LASIK (Laser in situ keratomileusis) Is NOT As Safe As Industry & The FDA Claim It To Be

 

For years, those damaged by LASIK have insisted to the FDA and industry that the severity of risks was severely understated and down-played. To this day, it still is! The $5,000+ these patients paid for their LASIK has cost them more medically AND financially. Although posted on the home page, emphasis should be given to the:

 

Top 10 Reasons To Avoid LASIK

Opinions By Damaged LASIK Patients For Those Considering LASIK

 

SOURCE

 

1. LASIK causes dry eye


Dry eye is the most common complication of LASIK. Corneal nerves that are responsible for tear production are severed when the flap is cut. Medical studies have shown that these nerves never return to normal densities and patterns. Symptoms of dry eye include pain, burning, foreign body sensation, scratchiness, soreness and eyelid sticking to the eyeball. The FDA website warns that LASIK-induced dry eye may be permanent. Approximately 20% of patients in FDA clinical trials experienced "worse" or "significantly worse" dry eyes at six months after LASIK.(1) In 2014, an FDA study found that up to 28% of patients with no symptoms of dry eyes before LASIK reported dry eye symptoms at three months after LASIK. Moreover, corneal nerve damage during LASIK may lead to a chronic pain syndrome known as corneal neuralgia.

 

2. LASIK results in loss of visual quality


LASIK patients have more difficulty seeing detail in dim light (loss of contrast sensitivity) and experience an increase in visual symptoms at night (halos, starbursts, glare, double vision/ghosting, ). A published review of data for FDA-approved lasers found that six months after LASIK, 17.5 percent of patients report halos, 19.7 percent report glare (starbursts), 19.3 percent report night-driving problems and 21 percent complain of eye dryness.(1)  The FDA website warns that patients with large pupils may suffer from debilitating visual symptoms at night. In 2014, an FDA study found that up to 46% of patients who had no visual symptoms before surgery, reported at least one visual symptom at three months after surgery.

 

3. The cornea is incapable of complete healing after LASIK

 

The flap never heals. Researchers found that the tensile strength of the LASIK flap is only 2.4% of normal cornea.(2) LASIK flaps can be surgically lifted or accidentally dislodged for the remainder of a patient’s life. The FDA website warns that patients who participate in contact sports are not good candidates for LASIK.

LASIK permanently weakens the cornea. Collagen bands of the cornea provide its form and strength. LASIK severs these collagen bands and thins the cornea.(3) The thinner, weaker post-LASIK cornea is more susceptible to forward bulging due to normal intraocular pressure, which may progress to a condition known as keratectasia and corneal failure, requiring corneal transplant.

 

4. There are long-term consequences of LASIK

 

•  LASIK affects the accuracy of intraocular pressure measurements,(4) exposing patients to risk of vision loss from undiagnosed glaucoma.

• Like the general population, LASIK patients will develop cataracts. Calculation of intraocular lens power for cataract surgery is inaccurate after LASIK.(5) This may result in poor vision following cataract surgery and exposes patients to increased risk of repeat surgeries. Ironically, steroid drops routinely prescribed after LASIK may hasten the onset of cataracts. In 2015, researchers reported that people who've had Lasik are having cataract surgery approximately 10 years earlier, on average, than people with the same axial lengths of the eye who have not had Lasik, and about 15 years earlier, on average, than the general population. Another study presented in 2015 found that people who have undergone LASIK have cataract surgery six years sooner than people who have not had LASIK.

• Research demonstrates persistent decrease in corneal keratocyte density after LASIK.(6) These cells are vital to the function of the cornea.  Ophthalmologists have speculated that this loss might lead to delayed post-LASIK ectasia.



5. Bilateral simultaneous LASIK is not in patients’ best interest


In a 2003 survey of American Society of Cataract and Refractive Surgery (ASCRS) members,(7) 91% of surgeons who responded did not offer patients the choice of having one eye done at a time. Performing LASIK on both eyes in the same day places patients at risk of vision loss in both eyes, and denies patients informed consent for the second eye. The FDA website warns that having LASIK on both eyes at the same time is riskier than having two separate surgeries.

6. Serious complications of LASIK may emerge later


The medical literature contains numerous reports of late-onset LASIK complications such as loss of the cornea due to biomechanical instabilityinflammation resulting in corneal haze, flap dislocationepithelial ingrowth, and retinal detachment.(8) The LASIK flap creates a permanent portal in the cornea for microorganisms to penetrate, exposing patients to lifelong increased risk of sight-threatening corneal infection.(9) Complications may emerge weeks, months, or years after seemingly successful LASIK.

7. LASIK does not eliminate the need for glasses

Since LASIK does not eliminate the need for reading glasses after the age of 40 and studies show that visual outcomes of LASIK decline over time,(10) LASIK patients will likely end up back in glasses – sometimes sooner rather than later.

Imagine putting on an old, outdated pair of glasses. That's what LASIK vision is like years after surgery -- your old prescription is permanently lasered onto your corneas. It's like being stuck with an old pair of glasses of the wrong power.

8. The true rate of LASIK complications is unknown

There is no clearinghouse for reporting of LASIK complications. Moreover, there is no consensus among LASIK surgeons on the definition of a complication. The FDA allowed laser manufacturers to hide complications reported by LASIK patients in clinical trials by classifying dry eyes and night vision impairment as "symptoms" instead of complications.(1)

 

9. Rehabilitation options after LASIK are limited


LASIK is irreversible, and treatment options for complications are extremely limited. Hard contact lenses may provide visual improvement if the patient can obtain a good fit and tolerate lenses. The post-LASIK contact lens fitting process can be time consuming, costly and ultimately unsuccessful. Many patients eventually give up on hard contacts and struggle to function with impaired vision. In extreme cases, a corneal transplant is the last resort and does not always result in improved vision.

10. Safer alternatives to LASIK exist


It is important to remember that LASIK is elective surgery. There is no sound medical reason to risk vision loss from unnecessary surgery. Glasses and contact lenses are the safest alternatives.

References:

  1. Bailey MD, Zadnik K. Outcomes of LASIK for myopia with FDA-approved lasers. Cornea. 2007 Apr;26(3):246-54.
  2. Schmack I, Dawson DG, McCarey BE, Waring GO 3rd, Grossniklaus HE, Edelhauser HF. Cohesive tensile strength of human LASIK wounds with histologic, ultrastructural, and clinical correlations. J Refract Surg. 2005 Sep-Oct;21(5):433-45.
  3. Jaycock PD, Lobo L, Ibrahim J, Tyrer J, Marshall J. Interferometric technique to measure biomechanical changes in the cornea induced by refractive surgery. J Cataract Refract Surg. 2005 Jan;31(1):175-84.
  4. Cheng AC, Fan D, Tang E, Lam DS. Effect of Corneal Curvature and Corneal Thickness on the Assessment of Intraocular Pressure Using Noncontact Tonometry in Patients After Myopic LASIK Surgery. Cornea. 2006 Jan;25(1):26-28.
  5. Wang L, Booth MA, Koch DD. Comparison of intraocular lens power calculation methods in eyes that have undergone laser-assisted in-situ keratomileusis. Trans Am Ophthalmol Soc. 2004;102:189-96.
  6. Erie JC, Patel SV, McLaren JW, Hodge DO, Bourne WM. Corneal keratocyte deficits after photorefractive keratectomy and laser in situ keratomileusis. Am J Ophthalmol. 2006 May;141(5):799-809.
  7. Leaming DV. Practice styles and preferences of ASCRS members--2003 survey. J Cataract Refract Surg. 2004 Apr;30(4):892-900.
  8. MEDLINE database of citations and abstracts of biomedical research articles. PubMed
  9. Vieira AC, Pereira T, de Freitas D. Late-onset infections after LASIK. J Refract Surg. 2008 Apr;24(4):411-3.
  10. Zalentein WN, Tervo TM, Holopainen JM. Seven-year follow-up of LASIK for myopia. J Refract Surg. 2009 Mar;25(3):312-8.

 

Timothy J. McCulley, Charles W. G. Eifrig, Norman J. Schatz, Steven I. Rosenfeld, and Byron L. Lam; Miami, FL, USA 33136; fax: (305) 326-6474; Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA; Inquires to Byron L. Lam, MD, 900 NW 17th St, Manuscript accepted 18 March 2002;

 

 

PURPOSE: To report infraorbital nerve dysfunction after laser in situ keratomileusis.

 

DESIGN: Observational case report.

 

METHODS: Neuro-ophthalmologic examination with brain and orbital magnetic resonance imaging (MRI) and orbital computed tomography (CT).

 

RESULTS: During laser in situ keratomileusis, two healthy women, aged 42 and 46 years, experienced acute onset of sharp ipsilateral cheek pain. Both cases occurred during manipulation of the eyelid speculum. Postoperatively, ipsilateral numbness and tingling or pain of the upper cheek was reported, and examination showed decreased sensation in the distribution of the infraorbital nerve. In both cases, brain and orbit MRI and orbit CT were normal. Both patients were managed medically. In one patient, mild symptoms persisted 1 year postoperatively, and in the second patient, moderate discomfort persisted 8 months postoperatively.

 

CONCLUSION: Infraorbital nerve palsy is a potential complication of laser in situ keratomileusis. Symptoms improve but may persist.

http://www.nzherald.co.nz/category/story.cfm?c_id=204&ObjectID=10412475

 

Excerpt:

Sunday November 26, 2006
By Miles Erwin

 

Concern has been raised about the long-term effects of laser eye surgery after a new study has shown that tens of thousands of Kiwis are likely to suffer defective vision from the surgery in their later years. Studies from Otago and Oxford Universities have shown that laser surgery for short-sightedness could cause haze, glare and blurred vision as people reach their 60s and 70s. Given that around 25,000 New Zealanders have had the surgery, Otago University head of ophthalmology Anthony Molteno said there could be significant legal class actions in the future, an issue that is causing major concern among eye surgeons.

In the procedure the central cornea is flattened. That provides better eyesight, but research shows that it seriously affects the movement of corneal cells, which affect sight. In a normal eye, the cells start at each end of the eye and migrate towards the centre. The top cells move quicker and meet the lower cells below the pupil. Where they meet, called the Hudson-Stahli Line, they create pigment, scattering light and causing glare, haze and blur.

As people age, that area increases and moderately affects eyesight but isn't a real problem, as the line is below the pupil.

"But after the surgery, the top cells move slowly down the flattened cornea, meeting the lower cells in front of the pupil. That causes haziness immediately, and most people who have the surgery see as though they're "looking through hazy spectacles", according to Molteno.

The new findings show the new location of the Hudson-Stahli Line will cause haze and glare in front of the pupil as people age. "The question is, is this permanent, and is it going to increase in the normal manner with age? If so, a lot are going to have a hazy, soft, fuzzy view of society as they get older. This is a long-term effect, and we are following these people. If this turns out to be a major effect, I presume it will one day see a major class action suit."

Molteno said the problems could be serious, with people unlikely to be able to drive. "Anybody who's had their cornea planed would be eaten by a lion at the water hole... If there was serious break-down of law and order, they would probably get shot before the others because they couldn't see so well."

At present, the process cannot be fixed. "The issue is really this: if you pay the private sector to do this, they do it at a profit and pay taxes. The question is how much of those taxes come to the public sector, and how much is it going to cost to clean up the mess? We don't know."

 

http://www.eyeworld.org/ewweek.php?id=454#4

 

 

Lawrence Tychsen, M.D., professor of ophthalmology and visual sciences and ophthalmologist-in-chief at St. Louis Children’s Hospital, St. Louis, developed specialized testing and now does refractive surgery on children with cerebral palsy, Down syndrome and neurobehavioral disorders such as autism. About 80% of children with severe neurological disorders have some kind of vision impairment, and about 10% have a severe impairment, according to a Washington University School of Medicine news release.

Tychsen and his staff perform LASEK, which is safer for children, who will inevitably rub their eyes after surgery. Because many of the children Tychsen treats are unable to communicate clearly or are uncooperative, he and his team use several noninvasive, electronic techniques to measure eyesight and determine the success of surgery. A computer-recording method measures the improvements that can be achieved in the visual brain while the child is awake. Other instruments take precise measurements before surgery while a child is under anesthesia. Although the surgeries can make significant improvements in the child’s vision and overall quality of life, most laser-treated children will see mild regression in their vision over time and about 10% require repeat surgery.

Refractive Surgery – A Ten Year Learning Curve

 

“Ten years on, LASIK appears to have lived up to its promise, although not for the high refractive errors that had originally been proposed.”

 

“In the case of LASIK, patient outcomes showed that visual outcomes became more unpredictable and unstable as refractive error increased.”

 

Read The Full Story

Cataract & Refractive Surgery Today April, 2006

Good—The Enemy of Great

 

Why refractive surgeons must adopt a philosophy of continuous improvement.

By Shareef Mahdavi

 

 

Excerpt: This past fiscal quarter, the refractive surgery industry in the US reached a milestone: 10 million eyes have now undergone laser vision correction since the first excimer lasers received FDA approval 1 decade ago. That's 5 million Americans who are ambassadors for LASIK as well as for the new generation of refractive procedures available to surgeons and their patients.

That's good, but it's not great.

I'm not sure whether the 10-million mark is a tremendous accomplishment or a mild disappointment. My columns over the past 5 years have explored why market adoption for LASIK and other refractive surgeries hasn't been higher, stronger, or faster. On the one hand, LASIK is now the single most commonly performed elective procedure in the country, far outpacing procedures performed by plastic surgeons. On the other hand, LASIK's adoption should be much higher given its high success rate (90% achieving a UCVA of 20/20), the immediacy of visual improvement (the "WOW" factor), and the emotional impact on peoples' lives ("It's a miracle!").

 

Read the entire article at http://www.crstoday.com/PDF%20Articles/0406/CRST0406_17.html 

Will customized LASIK procedures replace standard treatments?

 

http://www.birkacre.freeserve.co.uk/new_page_7.htm

BY William I. Bond, MD; Jack T. Holladay, MD, MSEE, FACS; Steven J. Dell, MD; James Schumer, MD; and Sam Omar, MD

 

Customized LASIK procedures, with their promise of tailored corneal laser treatments, will no doubt generate a lot of interest this year. In November 2002, the FDA approved the LADARVision system with the CustomCornea indication (Alcon Laboratories, Inc., Fort Worth, TX) for use in customized myopic laser procedures, and other companies expect similar approvals in 2003. Not only does customized LASIK look promising for those LASIK candidates who have been waiting for refractive technology to improve, but it is also exciting surgeons with its potential for re-treating patients who were disgruntled with their initial refractive surgeries. Cataract & Refractive Surgery Today asked a group of surgeons whether they thought this new-and-improved procedure would unseat conventional LASIK as king of the refractive marketplace.

William I. Bond, MD

I don’t think that customized LASIK will replace standard LASIK for at least the next 2 or 3 years. The first reason is that the technology simply isn’t there yet. We talk about customized LASIK technology a lot, but I don’t feel that it is accomplishing what it promises. We are only beginning to be able to measure higher-order aberrations with time-consuming and cumbersome technology, and we are unable to measure aberrations with any real sense of confidence or consistency.

The desire for surgeons to be able to say that they possess “customized” or “wavefront” technology pervades the refractive industry and currently far outstrips our ability to deliver concrete results to patients. There are so many treatments currently available that we refer to as “customized,” “wavefront,” “tailor-made,” or “individualized.” Abraham Lincoln said, “If you call a tail a leg, how many legs does a dog have? Well, the answer is four, because calling a tail a leg doesn’t make it a leg.”
More importantly, however, I feel that we are unsure of what we are trying to accomplish in correcting aberrations. I remember believing that a cornea free of aberrations was a desirable state of affairs, but that was just an assumption. Now, we are finding that 20/10 and 20/8 vision can exist with fairly large aberrations, and we aren’t certain what to make of that. Until we determine what the desired refractive state really is, the great hope for customized LASIK is to be able to address previously induced refractive surgical problems. This indication could be a godsend for long-suffering patients and their long-suffering surgeons.

Jack T. Holladay, MD, MSEE, FACS

In order to perform customized ablations effectively, the laser must be able to do what we ask it to do. Specifically, there is not a single laser on the US market today that delivers the appropriate overall energy for the ablations we perform. The reason is that the lasers are calibrated on a flat surface, so their energy is always delivered perpendicular to the treatment site. Because the cornea is not flat, the lasers today only deliver the appropriate amount of energy to the central point of the treatment site, where it is perpendicular. As the beam moves farther out, regardless of the type of beam it is, it strikes the periphery of the treatment zone obliquely, so its energy diminishes from what is necessary for the proper ablation. Our data show that the lasers are actually undertreating in the periphery—at 6.0 mm, it is about 25% reduced from its designated calculation—and in doing so, they make the cornea more oblate, rather than preserve its natural prolate shape.

I recognized this problem with excimer lasers about 3 years ago, and I have since added a new algorithm to the software of the LaserScan LSX excimer laser (LaserSight Technologies, Inc., Winter Park, FL) that increases the amount of laser energy to compensate for hitting the cornea obliquely. Of the 20 patients I have treated with this new software, all have postoperative corneas that are shaped exactly like virgin corneas. They do not have a shrinking optical zone such as those induced by current standard treatments, and these patients’ contrast sensitivity and wavefront measurements are as good as those of patients who have never undergone surgery. Moreover, these treatments were standard—not what we would normally refer to as a customized ablation.1 Correcting the systematic calibration errors in the lasers will produce better results than the wavefront-guided ablations performed today.
From my perspective, there will not be significant differences between the outcomes of customized over conventional ablations, but there will be a noticeable improvement if we calibrate all laser systems to compensate for their error when they hit the cornea obliquely. I believe that correcting the calibration error will account for approximately 99% of the improvement that patients will then receive from corneal laser surgery, and the other 1% will be attributable to customized wavefront technology. The aberrations that wavefront technology corrects are minute compared with the spherical aberrations induced by the calibration error of the lasers. I also feel that we currently understand too little about wavefront technology to significantly benefit patients who see well with glasses and contact lenses; I think that patients with more difficult visual problems will benefit most from customized ablations.

Steven J. Dell, MD

With the widespread use of customized ablation just around the corner, are we about to witness the technological obsolescence of standard LASIK? The answer is more complex than it may seem on the surface. The concept of customized treatment is very appealing, both to patients and surgeons. We obtain a unique map of each individual eye and custom tailor the treatment accordingly. This obviously will be better than an “off-the-rack” treatment, right?

Some early studies with wavefront treatments have demonstrated better UCVA and BCVA as compared with standard treatments, with fewer induced higher-order aberrations. In many cases, wavefront treatments have reduced spherical aberration in particular and improved night vision. These are remarkable achievements, but which specific aberrations should we eliminate? In a very interesting study presented at the 2001 AAO meeting in Orlando, Florida, Steven Schallhorn, MD, examined aviators at the Navy’s Top Gun school in Nevada. He looked at higher-order aberrations in individuals who had not undergone any type of refractive surgery. Surprisingly, he found that individuals with the very best UCVA had more higher-order aberrations than those with worse UCVA. Should we aim to leave some higher-order aberrations on the cornea, and if so, which ones? This question obviously warrants further study.

Additionally, it has been shown that creating a LASIK flap induces aberrations that are unpredictable. Does this fact steer us more in the direction of surface ablation for customized work? Perhaps, but the epithelial remodeling that occurs for months following surface ablation creates its own constellation of aberrations. Even after LASIK, we see substantial epithelial changes for many months. It will also be interesting to see how lenticular changes affect the situation. In my practice, the average patient requesting refractive surgery is 41 years old, and many individuals are in their 50s. How will these patients fare in the long term, and how will we deal with their residual aberrations when we extract a substantial component of the aberration equation at the time of cataract surgery? Pupil size is another factor that dramatically affects the wavefront profile of any given eye. As this variable changes from moment to moment and in general shrinks with time, how will this influence matter?

Customized ablations hold huge potential in refractive surgery. There are many patients with irregular corneas resulting from problems with prior refractive surgeries who may benefit substantially from this technology. Applying customized ablation to the mainstream refractive surgery patients will require careful consideration of all these issues. The analogy of a “made-to-measure” suit versus an “off-the-rack” suit certainly applies, but we should bear in mind that, if we gain or lose 5 pounds in a few years, or styles change, we can simply buy another suit. Customized ablation is for the duration.

James Schumer, MD

Wavefront technology and customized ablations are in their infancy. However, the tremendous impact these advances will have on our surgical strategies and treatment options is quickly becoming clear. In order to answer the question of whether customized treatments will replace standard LASIK procedures, we first have to agree on the definition of customized ablation. Does it mean simply wavefront-guided ablations, or does it mean reducing the higher-order aberrations of an eye using wavefront technology? This distinction is not a subtle one and is very important to understand for the following reasons. Alcon’s LADARVision 4000 is the first excimer laser in the US approved for customized ablation. However, the pre- and postoperative wavefronts taken of the participants in the study show that their average higher-order aberrations increased after treatment. Although the LADARVision’s customized-ablation approval will allow surgeons to treat eyes using wavefront technology, we are not yet able to reduce pre-existing higher-order aberrations. In fact, we are still increasing higher-order aberrations with our current treatments.

Clinical diagnostic wavefront analysis is teaching us that visually significant higher-order aberrations measured preoperatively are not the norm in our refractive surgery population. In other words, completely correcting sphere and cylinder surgically, without inducing visually significant higher-order aberrations, will delight nearly 100% of our refractive surgery patients. However, it is the atypical refractive surgery patient who complains of higher-order aberrations preoperatively, while most postoperative complaints are due to surgically induced higher-order aberrations (ie, spherical aberration).

Therefore, I feel that wavefront-guided customized ablations will eventually supplant the phoropter-guided LASIK procedures surgeons currently perform. The phoropter, manifest, and cycloplegic refractions will become safety checks included in preoperative evaluations, but they will no longer be the driving parameters of the excimer laser treatment. However, customized ablation (ie, treating the higher-order aberrations of an eye) will not be the typical treatment objective in the refractive surgery population, due to the ocular demographics that show that the number of lower-order aberrations far exceed higher-order aberrations in terms of visual significance. Formulating treatment parameters that eliminate and prevent the induction of higher-order aberrations remains elusive, but the journey will be stimulating and provide us with true customized-ablation (ie, treatment of higher-order aberrations) potential.

Sam Omar, MD

"New-and-improved" is a marketing tactic employed by companies in order to boost their corporate bottom line. Physicans need to cautiously evaluate any revolutionary or evolutionary refractive technology. The refractive surgery industry is extremely motivated to promote new-and-improved technologies, particularly in the form of wavefront-guided refractive surgery, which may supplant current, “conventional” LASIK surgery. Unfortunately for the industry, wavefront technology is still in its infancy, and conventional treatments now feature improved ablation algorithms, smoother ablations, blend zones, and optimized optical zones, which all eliminate many differences between conventional and wavefront-guided LASIK treatments. This comparison has been well demonstrated in countries that are 12 to 18 months ahead of the US in developing refractive technology, and thus far, customized LASIK procedures have not displaced conventional LASIK in these advanced, foreign settings.

Until our understanding of wavefront technology improves, refined conventional refractive treatments may actually outpace wavefront treatments for consistent, effective, and stable refractive results. The potential of conventional treatments can be seen when comparing the postoperative results from specific excimer platforms with the wavefront-guided postoperative results of competing excimer laser platforms. Prior to achieving “supervision” for virgin eyes, the refractive industry needs to develop additional treatments to re-treat postrefractive surgery patients who manifest suboptimal outcomes with decreased BSCVA and decreased-quality mesopic/scotopic vision. Once refractive surgeons develop more effective methods for treating irregular astigmatism and safer microkeratome technology, refractive surgery’s penetration into the general population will tremendously enhance the industry's perceived and actual safety rate.

In order for wavefront-driven excimer treatments to displace conventional LASIK, a number of philosophic and technological hurdles must be overcome. Due to the pioneering work of Cynthia Roberts, PhD, of Columbus, Ohio, and Dan Reinstein, MD, of Cambridge, England, wavefront researchers have begun to comprehend the effect of biomechanical changes in the cornea induced during the lamellar surgical portion of LASIK. The fact that so few wavefront investigations include standardized microkeratome variability partially demonstrates the limits of current refractive surgery knowledge. Because wavefront treatments require micron and submicron resolution, a greater working knowledge of the factors involved with epithelial and stromal wound-healing responses will be critical to maximizing successful customized ablations. Elevation-based topography data must be incorporated into these treatments in order to provide the highest-probability “best fit” for a customized ablation. Current excimer laser beam delivery and tracking technology is rapidly improving, but it still lags behind what is theoretically required to perform wavefront-driven customized ablations. Additionally, adaptive optics, which introduce virtually any desired aberration profile into a subject's eye, must be refined to evaluate a patient’s vision for each controlled aberration profile. This “wavefront phoropter” or “visual simulator” would allow surgeons to determine the exact relationships between specific aberrations and visual quality.

Despite the best designs of current wavefront investigational trials, until the issues described previously are rigorously developed and applied, any significant visual improvement via customized wavefront ablations will be entirely accidental and difficult to reproduce. Therefore, it is unlikely that in the near future customized LASIK will unseat conventional LASIK as king of the refractive marketplace.

 

William I. Bond, MD, is Director of Bond Eye Associates in Pekin, Illinois. He holds no financial interest in any technology discussed herein. Dr. Bond may be reached at (309) 353-6660; This email address is being protected from spambots. You need JavaScript enabled to view it..

Jack T. Holladay, MD, MSEE, FACS, is Clinical Professor of Ophthalmology at Baylor College of Medicine in Houston, as well as Medical Director of LaserSight Technologies, Inc., in Winter Park, Florida. Dr. Holladay may be reached at (713) 668-7337; This email address is being protected from spambots. You need JavaScript enabled to view it..

Steven J. Dell, MD, is Director, Refractive and Corneal Surgery at Texan Eye Care in Austin, Texas. He holds no financial interest in any product or technology mentioned herein. Dr. Dell may be reached at (512) 327-7000; This email address is being protected from spambots. You need JavaScript enabled to view it..

James Schumer, MD, is in private practice at Eye Surgery Consultants in Mansfield, Ohio. He holds no financial interest in any product or technology mentioned herein. Dr. Schumer may be reached at (419) 525-3737; This email address is being protected from spambots. You need JavaScript enabled to view it..

Sam Omar, MD, is from Advanced Vision Institute in Orlando, Florida. He holds no financial interest in any product or technology mentioned herein. Dr. Omar may be reached at (407) 389-0800; This email address is being protected from spambots. You need JavaScript enabled to view it..

1. Holladay JT, Jane, JA. Topographic changes in corneal asphericity and effective optical zone size following LASIK. J Cataract Refract Surg. 2002;28:942-947.

Clin Experiment Ophthalmol. 2005 Apr;33(2):115-6.

Mantry S, Shah S.

Excerpts:

"Problems identified following excimer laser surgery include: increased risk of dry eye, corneal availability for eye banking, effect on intraocular pressure (IOP) measurements, effect on intraocular lens calculations and iatrogenic keratectasia. As the population of patients who have undergone refractive surgery increases, increasing numbers will need cataract surgery and the alteration in corneal power makes biometry unpredictable. Further work is required to accurately calculate appropriate lens power following photorefractive keratectomy (PRK) and LASIK."

"Indeed the long-term problems created by laser refractive surgery are not yet a major issue, but soon will be."

Most traits we can measure in humans vary continuously. Like blood pressure. Blood glucose levels. Corneal thickness. Plot the measurements you obtain for any such trait across enough individuals and you obtain a bell curve. Individuals at the extremes of the bell curve are more rare... and if the measurement you're making is a physiological measurement, there may be a disease process associated with occupying the extremes of the bell curve.

Extremely high intraocular pressure may mean glaucoma.

Extremely thin corneas may predispose to ectasia.

The threshold concept: there is a certain physiological value or threshold, when crossed, results in disease symptoms.

LASIK patients, on average, have lost more than 40% of their corneal nerve density 3 years after LASIK. This may leave a young male, who is in a low risk group for dry eye asymptomatic, while a middle aged female who has lost a similar % of her pre-operative nerve density may experience debilitating dry eye.

Same situation with contrast sensitivity. All patients lose contrast sensitivity... depending on age and other factors, not all of them experience this loss as disabling/debilitating.

An important point is that all patients who have LASIK lose some visual and neural reserves. This means as they age they may cross the threshold to a symptomatic and/or disease state sooner.

People who never would have lost their ability to drive at night or enjoy comfortable vision may lose these abilities at middle age or even sooner because of laser eye surgery.

The point is that refractive surgery has robbed millions of their visual and corneal nerve reserves.

Millions of Americans have been pushed nearer the threshold for dry eye, loss of functional night vision, and corneal failure (ectasia).

Contributed with permission by Meredith Perry

 

The eyes are the windows to the soul. And the relatively new LASIK procedure supposedly can make those windows crystal clear.

This quick and painless procedure produces perfect vision.

LASIK surgery has helped millions of people see clearly, yet for a small, but growing number of patients the procedure has not helped, but hurt. For Dominic Morgan the surgery seemed like a dream come true -- but turned out to be a nightmare.

"I had my surgery done April 23 and April 30, 1998".

Dominic's surgery did not go as planned, and now he suffers the consequences of that ten minute procedure every day of his life.

"I had problems from the get-go".

Dom's problems included halos, glare, blurry and fluctuating vision, and starbursts. But for thousands, basic LASIK surgery is simple and harmless.

Dr. Sarah Hay performs LASIK. "I’m going to put drops in your eyes and numb your eyes. The surgery does not hurt. I’ll put the speculum in so you don't have to worry about keeping your eyes wide open. I'll put that suction ring on to create the flap, then I'm going to ask you if you see that aiming light. Also when I put that suction ring on you do lose your vision for a little bit, and I'll remind you of that before I do it. The pressure you feel does not hurt like the pressure on your arm with a blood pressure test. I'll ask you if you see the aiming light, and it is very important that you tell me you see it, because that is where I need your cooperation. I’ll lock on the tracker and tell you how long it will take for the laser to treat your prescription. Now when you get up some of you will think a miracle just happened, but it is normal for your vision to be blurry. Well, I've cut your cornea, fired the laser, rinsed it, reattached it and lubricated it. It is not going to be clear right away. The next day everybody should be functional"

And it was for Dr. Hays' LASIK patient Jackie Small. The surgery was painless and successful. Can it be this easy? Don't throw away your glasses quite yet.

Dominic Morgan wanted to get LASIK surgery so he could do just that - throw away his heavy glasses.

"I had big thick glasses, and they kept sliding down in the summer time because the glasses were so heavy".

LASIK advertisements can be seen everywhere. And they all have one thing in common - promising the end of glasses. So the public is led to believe LASIK equals a life without glasses. That's not entirely true.

"Then you can have reading difficulty. So that will not change. That deteriorations due to aging is going to happen whether or not you get LASIK. That will still bring about reading deficiency, and you might have to get reading glasses. And a very small percentage will have distance deterioration" says Dr. Ming Wang.

Dr. Ming Wang of Nashville, Tennessee dedicates most of his time to LASIK patients with complications - patients similar to Dominic Morgan. Dom, as he likes to be called, had retinal problems since he was an infant due to his premature birth.

"They (doctors) told me I was a good candidate. I went to their retinal doctor and he said I was fine".

Dr. John Herman says "My statement to virtually everyone I’ve ever talked to about this - three out of four maybe nine out of ten people who had laser vision correction were not good candidates - meaning the ones with complications".

Dominic said the same of his doctor "In August I saw another doctor out of curiosity. The doctor told me I should not have been considered for surgery. Every cornea specialist I have talked to since them told me the same thing".

Dom wishes he would have consulted those doctors before his surgery. His piece of advice is to seek many other opinions before the laser hits your eyes.

Dr. John Herman of Pittsfield, Massachusetts says there are many tests that need to be done before considering LASIK. And most LASIK places overlook them.

"When they look at your eyes before laser surgery there is a lot of things they don't do. In my opinion it's an inadequate report that comes out of those places".

Dr. Ming Wang states - "First and foremost you need to make sure you are a good candidate. Second is the instrumentation. It is very challenging for a person to figure out the differences between all of the lasers. Ask other doctors".

And Dominic Morgan wished he had done just that. Because if he did he might not be where he is today.

(VISUAL SHOT OF QUESTIONNAIRE) - Dom found out his laser surgeon Anita Nevyas-Wallace had used a non-FDA approved laser. A laser her father Dr. Herbert Nevyas had invented. And later Dom discovered that there were eleven lawsuits because of that laser's use.

"Since they dismantled their laser two years ago they haven't had any lawsuits against them".

Drs. Herbert Nevyas and Anita Nevyas-Wallace of Philadelphia did not hide the fact they used a non-FDA approved laser.

Dom stated - "They give you a series of questions. Afterwards you answer true or false. 'The excimer laser used for my procedure has been studied and proven by the FDA'. I marked true. It was false".

Dr. Herbert Nevyas invented the laser and used it on patients for research purposes, including Dom. He hoped to have it approved by the FDA. And Dr. Nevyas did not use the laser only on Dominic, but also on Joe Wills' husband, Keith.

Joe Wills states "Dr. Nevyas called him to delay the enhancement surgery. At that point he told my husband he would have to wait for the FDA approval. When we got to trial we realized he was using his own invention".

Both Dominic and Keith sued the Nevyas' - and they both lost.

" Philadelphia courts ripped my case apart. I was not allowed to bring in anything pertaining to the FDA" Dom said.

Because Dominic could not bring the fact of the non-FDA approved laser into the trial he could only sue on negligence. And Dr. Nevyas said he had no way of knowing the surgery would fail.

Less than one percent of patients who have received LASIK have experienced serious, vision-threatening problems - like Dom's. The incidence of less serious complications such as halos and glare is between 3 and 5 percent.

Dom states "Nighttime was a joke. I had the glare, I had the ghosting, I had the starbursts. I couldn't focus on anything. I expressed my concerns to them and they just kept telling me as my eyes healed, I’ll lose all of that and I'll get better. They told me it would take up to three months the first time. Then three to six months. Six to twelve months, and then after a year they told me because of my problems I had, because of the history I had, it could be longer. And then they told me it could be permanent".

Joe Wills describes her husband's adverse effects from the surgery, and they are eerily the same as Dominic's.

"My husband is legally blind at night and has multiple vision. He has the glare, the halos, the foggy vision".

And like Dominic, there is no cure for Keith's vision.

"When my husband had his two year anniversary of his surgery, he was supposed to go in for another evaluation. They told him to go for a second opinion and they evaluated him and told him there was not enough cornea left to repair his eyes".

So what went wrong with these surgeries? Is the laser to blame? Or the doctor?

Joe Wills - "Dr. Nevyas told him to look at the red light. My husband told him he could not see the red light. And it got real quiet in the operating room and there were whispers amongst the doctor and his assistants. The doctor left the room and then came back in and asked again if he could see the red light. My husband said he couldn't. The doctor then told him to look as straight as he can and don't move your eye".

Dominic was once a mainframe computer operator making 50,000 dollars a year. He is now legally blind and living on disability Social Security.

"I was working, I was driving, I was doing everything anyone else would do. I don't do anything anymore - I can't even sit at a computer at length. There's no clarity to anything. I have total loss of night vision. I did read quite a bit, now I'll pick up a book, and I was used to going through it in two days. Now it takes me a couple of months. The book is up to my face like this".

These complications are never mentioned in advertisements.

Dr. Ming Wang States "I think there is too much advertising of only the good in LASIK surgery. The general public should be educated about risks and limitations. LASIK surgery should be looked at with a balanced viewpoint. First and foremost like all medical procedures it has risks and complications. And very often I have patients saying make me have 20/20 vision. And I say can you name a medical procedure that is perfect? Why should the laser vision correction be any different?"

And that is a great point. LASIK has been extensively advertised as being a miracle surgery - but there are risks involved. And as with any surgery some patients come out happy, while others deal with complications. Diana Howard, of Birmingham, Alabama, dealt with the complications. Her eyes were under corrected, and eventually she had to get the surgery done by another doctor, and pay for it a second time.

"I went to this place and I had my surgery done, and I complained because I noticed my eyes were not corrected, and I told them the problems I had and they never called me back. So I sent them a letter saying that I had problems and that I wanted my money back or the surgery to be corrected. I never heard anything from them again. A couple of months later I read in the paper where they had a bunch of people who sued because the place I went for the surgery apparently the calibration of the laser was incorrect. So a lot of people had problems. But I didn't know about the lawsuit until I read it in the paper. And by that time it was too late to do anything".

Diana might have thought it was too late for legal action, but Dr. Herbert Nevyas did not. He is now suing Dominic. That's right - he is suing Dom.

"They are suing me because of my website. The point of my website is to let other people know there are risks, to be very careful if you are not a candidate, such as myself. Don't be misled".

WWW.lasiksucks4u.com states Dom's feelings about LASIK and Dr. Nevyas very clearly. But Dom says his intention is not to discredit the Nevyas'.

"My intention is strictly to put the truth out there".

Dominic's problems all began with a non-FDA approved laser. Technology causes some of the botched surgery. But lack of training also creates LASIK complications. Currently the medical boards across the country are only requiring a weekend training course for LASIK surgeons.

Dr. Herman states "It turned out they had a training session for optometrists and a training session for surgeons. Well I couldn't make the session for optometrists so I knew the guy in charge and I called him up, and I went to the one for surgeons. Basically the training session was the same as the weekend before for the optometrists. And I could remember driving home saying to myself these cataract surgeons are going to go do laser surgery next week. So the bottom line is there are no stringent rules applied to the surgeons themselves".

And Dr. Ming Wang "I think we need to go back. Would you allow a surgeon to perform open-heart surgery if all he got was a weekend training?"

"It's a weekend course - and they don't do human eyes. They do cow eyes, and then they are ready to do human eyes? And if you spoke to most surgeons although they would be defensive because it is their system. If you got a couple of beers in them they would say it's nonsense" says Dr. Herman.

Laser surgeons cut the cornea with a microscopic, hand-held razor during laser surgery. This is the most dangerous part of the procedure and where the most risk is involved.

Dr. Ming Wang states "The cornea is the thickness of a couple of strands of hair, and a laser surgeon has to cut a flap in the cornea using a hand-held razor. They must do this without cutting through the cornea".

"My guess is there's more surgical errors than there are bioengineering errors" notes Dr. Herman.

Lawsuits, lasers, insufficient training, the FDA - LASIK surgery has never seemed so complicated. What happened to that quick and painless surgery we all know and love? It never existed.

"Every citizen should go by the fundamentals. Make sure you are a good candidate, make sure you have the best technology. Ask other doctors where you would go for your own eyes" cautions Dr. Ming Wang.

The eyes are the windows to the soul. And you never know what you have until you lose it.

Dom adds, "Socially I use to go out. I use to go to bars. I use to do a lot of traveling - going fishing, casino (laughs), now I don't like to do anything especially at night. You can't enjoy what you can't see".

Due to litigation from a patient previously interviewed this article has been edited to remove all reference of patient.

I wish to acknowledge with much appreciation for contributing with permission to post on this site by Professor James O'Reilly the following study on Lasik liability exceptions:

E-Text Version of article published in 71 Univ. Cincinnati Law Review 541 (2003), copyright Univ. Cincinnati 2003 

 

AN EYE FOR AN EYE:

FORESIGHT ON REMEDIES FOR

LASIK SURGERY’S PROBLEMS  Prof. James O'Reilly1

SUMMARY:

... Laser eye surgery is remarkable. ... " The FDA requires device sponsors to report the number of patients who seek a second LASIK procedure to improve vision after the first surgical results were inadequate, but "no laser company has presented enough evidence for the FDA to make conclusions about the safety or effectiveness of enhancement surgery. ... Night vision deficiencies are "one of the main challenges" to improving laser eye surgery. ... The bold and attractive promises being made in LASIK advertising by eye surgery marketing corporations, some of whom are publicly traded entities, may give rise to express warranty claims as well as claims against the individual surgeon or the surgeon's corporate entity as conventional malpractice claims. ... The FDA has jurisdiction over the advertisements for a prescription medical device and, although the FDA requires that warnings be stated for prescription drug ads made to consumers, it does not require the same communication about risks in LASIK advertising. ... The injured LASIK patient's compensation claim against a LASIK device maker is likely to be barred by the Supreme Court's interpretation of the Food Drug & Cosmetic Act to prevent state verdicts asserting design defect claims against FDA- approved medical devices. ... 

TEXT:

[*541]

   I. Introduction

   Laser eye surgery is remarkable. Never before in American medical history have 3 million people each year responded to massive advertising by paying for an innovative, elective surgery. Never before have surgeons competed so vigorously on price; and never has a surgery been so skillfully isolated from liability lawsuits. If LASIK eye surgery becomes the Mass Tort of 2025, will Americans regret accepting it as the benign 20/20 solution of today?

   The first decisions in a series of liability suits against LASIK surgeons have been reported, with one plaintiff receiving a $ 4 million verdict. n1 Yet, the procedure is too new for a body of reported appellate precedent, so this review must be a forward-looking prediction of future judicial behaviors. This article examines the conundrum that an injured LASIK patient, whose vision deteriorates several years after the surgery, may be unable to find a viable defendant, thus leaving the customer without an effective remedy.

   II. Understanding the Context

   What is LASIK Surgery?

   Open your eyes, read a newspaper, watch a television, see a billboard, and elective surgery advertising hits your eye. From thousands of dollars down to hundreds, the competition to sell this mass volume elective surgical procedure has driven down prices. The specific service that was to be provided to an estimated 3,135,000 patients in 2002 is LASIK. n2 LASIK is the acronym for "laser in- situ keratomileusis," a form of computer software-guided cutting of the cornea in the eye using [*542] laser light beams. LASIK and other eye surgery procedures n3 flatten the central curvature of the cornea of the eye, with a flap of skin peeled back in order to effectively alter the ability of the eye to see without external spectacles or contact lenses. A Pennsylvania court summarized the mechanics of the LASIK process in a succinct summary:

   During the LASIK procedure, after the surface of the eye has been anesthetized by eyedrops, a microkeratome is used to create a flap in the outer layer of the cornea which is folded back to allow an excimer laser access to theexposed corneal surface. Computer-controlled laser beams then remove thin layers of corneal tissue to reshape the curvature of the cornea so that visual images will focus directly onto the retina, thereby improving visual acuity. The corneal flap is returned to its original position without utilizing sutures, and a protective "bandage" contact lens is applied to prevent the eyelid from rubbing against the eye surface as the outer layer of cells regrow and the flap re-adheres. n4

   Measurement of the eye and setting the correct parameters into the computer- controlled laser equipment appear to be the principal determinants of surgical success. An experienced surgeon can perform many surgeries in the same day by using the staff of an outpatient surgery facility to prepare the patient. Though the equipment is constantly being improved, the computer controls depend on the accuracy of the data being fed into the system by a skilled surgeon during the pre-surgical evaluation of the patient.

   The reader may choose to read more of the technical details of the surgery elsewhere. n5 This paper will deal with LASIK, but some of the issues are relevant to other processes. Relative to older forms of such refractive surgery, LASIK does not appear to produce greater glare or halo effects during the early stages after surgery. n6 However, the long-term consequences of LASIK are still unknown.

   Is LASIK Surgery Safe?

   As with any surgery penetrating through body tissue, cells are affected by the cutting of corneal tissue. The eye cells heal differently with [*543] different patients whose personal health and other characteristics will affect recovery. In the event that slowly-developing cellular changes in the cornea may cloud the vision of LASIK patients in future years, we simply do not know how a LASIK procedure's adverse effects will manifest themselves. An experience base of five or more years may be needed to follow the progress of patients whose corneal cellular changes are manifested by slow blurring of the vision or the appearance of nighttime glare effects that hinder their ability to drive. This poses the same causation challenge that lawyers experience in other medical delayed-effects situations: the manifestation of eye deterioration attributable to the cutting of cells may be hard to differentiate from deterioration attributable to the effects of normal aging or of unrelated eye problems. For the short term, LASIK appears to be safe, with a small number of adverse effects, as discussed later in this article.

   Why Is LASIK Different from Other Surgical Procedures?

   Surgery is typically a drastic interventional response to a medical emergency or to the failure of an organ or bone system. Any surgery carries risks, especially the in-patient surgery that involves the risk of hospital-related infections. The development of skilled surgical techniques involving micro-surgical interventions has made American surgical capabilities well respected around the world.

   But not all surgical interventions respond to health necessities. Persons who find contact lenses annoying or spectacles inconvenient are being pressed to "try the safe and affordable alternative: LASIK." n7 Americans are willing to pay for various types of elective surgery for anatomical flaws and cosmetic defects. Because the word "cosmetic surgery" draws angry rebukes from eye surgeons, the LASIK processes can at best be called "improvements on nature," rather than the classic use of surgery for a needed remediation of injuries. The wave of 3,300,000 annual LASIK procedures in the United States may be the greatest volume of surgical procedures ever voluntarily undertaken by consumers in the history of medicine. n8

   The sales target for expanding LASIK is thirty-five percent of the 180 million Americans who may need vision care. n9 Of course, such a goal is ambitious, and it amplifies the concern that even a small percentage [*544] of damaged eyes might mean that tens of thousands lose their optimal eyesight as a result of flawed surgery. The market's size is great and the potential downside for a fraction of that population could produce substantial damages. One symptom of the fluid nature of change in this marketplace is the way in which the manufacturers earn their profits: new eye lasers, once approved, are leased to surgeons in return for a per-surgery fee, with new equipment emerging continually in a hot, competitive climate.

   III. The Regulatory Context

   FDA's Twelve-Month Norm

   A traditional question arises again: how much of a database of safety experience should society demand before a new technology is "safe enough" for use on humans? The Food and Drug Administration (FDA) has statutory jurisdiction over medical devices. n10 The FDA has used this authority to specifically approve numerous laser devices for surgical use on the eye. n11 So, it would then seem that the consumer expects to be fully protected by prior government approval before the LASIK device enters the competitive marketplace.

   But, the human clinical studies of comparative surgical results, needed for FDA approval of a new laser eye device, are only required to study patients in the small test sample for twelve months post-surgery. Some studies go to twenty-four months, continuing after the approval of the new device. n12 The laser device maker must supply extensive information about the machine from which the FDA can evaluate the safety and efficacy of the design, and these "premarket approval applications" can be voluminous. n13 But the experience base is relatively short and cannot be expected to catch long-term deterioration effects on the eye, if such effects occur. This does not mean LASIK is going to be found to have a higher risk than we now expect-we just do not know. If ill effects do not arise among the three million customers per year, then a definitive risk conclusion can be made at some future date.

   [*545]

   A review of the FDA website's summaries of product safety for the approval of new laser devices n14 consistently shows that manufacturers submit, and the FDA grants approval based upon, twelve months' experience with the new laserdevices. The FDA examines both the adverse events reported during the twelve month post- surgery follow-up and the complications from surgery reported by the surgeons. The FDA's Office of Device Evaluation in the Center for Devices & Radiological Health then makes a decision about the product's acceptability. n15

   The protection of LASIK surgery patients by the regulatory intermediary, the FDA Office of Device Evaluation, is premised on experiences of up to twelve months post- surgery. By its own public admission, the post-approval examination of medical devices "is not working well." n16 The FDA requires device sponsors to report the number of patients who seek a second LASIK procedure to improve vision after the first surgical results were inadequate, but "no laser company has presented enough evidence for the FDA to make conclusions about the safety or effectiveness of enhancement surgery." n17 Possibly, vision effects may be manifested after a longer period, as reports slowly arrive that demonstrate evolving patterns of experience with clouding of vision as cells change. Such effects might be noticeable after several years have passed: for example, when a patient changes eye doctors and complains about the results promised by an earlier eye surgeon who sold a LASIK procedure as the ideal solution for that person's desires.

   In the liability claims context, the time of reported effects becomes significant. Corneal surgery of various types has a long history, but LASIK's laser/computer interface combined with mass marketing isa relatively recent novelty. A few warning flags are visible in the medical literature, n18 but no one can reliably predict the percentage of ten or twenty-year post-surgical experiences that will be adverse for LASIK patients. It may be that LASIK produces no adverse long- term effects. [*546] On the other hand, LASIK might cause a more rapid and serious cellular degeneration than other causes. The nexus of uncertainties regarding cellular change, rates of deterioration, the value of a twelve month pre-approval study as a predictor, and patient intolerance of vision problems, make for an intriguing challenge to the would-be tort plaintiff.

   How are the Surgeons Regulated?

   The FDA has no jurisdiction over physicians such as the surgeons who use the laser equipment. n19 The FDA requires adequate labeling for proper use by physicians n20 but cannot police the physicians themselves. Surgeons' performance is left to the state medical boards n21 and to the private malpractice system. n22

   The FDA tracks post-approval rates of injury under its Medwatch program of voluntary adverse effect reports on medical devices, n23 as explained on the FDA's Center for Devices website. n24 The surgeon who finds a malfunctioning LASIK device could file a report online with the Medwatch system but is not required to do so. Congress responded to complaints by manufacturers and hospitals, severely restricting the FDA's medical device user reporting authority n25 in the 1997 amendments to the device statutes. n26

   IV. The Liability Context

   Identifying Causes of Action

   At the rate at which LASIK surgery is being sold to new patients, even a small percentage of vision loss claims-a fraction of the millions of cases-could produce a significant volume of potential tort suits. This is a statistical certainty, since the smaller occurrence of adverse eye [*547] effects would become manifest slowly, as the several millions of LASIK recipients age during the years since their eyes were cut by the surgery. n27

   The classic tort negligence test requires a showing of foreseeability of the injury and fault by the responsible product manufacturer or physician. Modern strict liability imposes a compensation obligation on the manufacturer of a defective product regardless of fault n28 and leaves malpractice law to remedy the problems caused by the professional user of the device. Strict liability shifts the costs of injury to the designer and marketer of the product that caused the injury, without the need to show fault or even proof that the injury was foreseeable. n29

   However, strict liability is a policy that carries an important exception-it does not apply if the product offers a special societal benefit like a rabies vaccine or an important pharmaceutical to cure cancer. n30 These latter products were deemed by the creators of modern strict liability to be "unavoidably unsafe," and, thus, subject only to negligence law norms in order to prevent the advance of medical progress from being retarded by the costs of strict liability. n31

   The Third Restatement Shield

   One of the controversial aspects of the 1997 adoption of the Third Restatement of Products Liability was the virtually complete shield from strict liability for prescription drugs and devices that have any beneficial effect for any class of patients. n32 The concept holds that with the existence of a class of patients that will benefit from the device, the device can be sold for all other classes as well and will be immune from the strict liability analysis. n33 For example, leprosy is rarely encountered among United States residents, but a drug that was beneficial to leprosy [*548] patients would not be vulnerable to challenges against its marketing for some other medical indication, such as cancer. The express predicate for this exclusion from strict liability was that the FDA "adequately review(s) new prescription drugs and devices, keeping unreasonably dangerous designs off the market." n34 If one believes the FDA achieves this goal, the Third Restatement makes sense.

   Eye laser devices benefit from the protective shield that the Third Restatement seeks to apply to prescription-only products. Arguably, the availability of laser surgical devices benefits some patients whose eyes are medically impaired and for whom the corneal surgery has a therapeutic purpose. A contrary argument can be offered, however, that three million annual uses of a surgical tool for appearance and aesthetics far outweigh the smaller number of uses of these devices for cases of real medical necessity.

   The Case of the Disappearing Defendants

   In the event that even a small number of LASIK patients experience eye difficulties later, a small fraction out of three million customers each year is still a substantial population of potential plaintiffs. A significant concern for these plaintiffs is that tort law lags far behind laser technology. Lasers are improved each year, but liability systems lag behind, so no compensation for injury may be available to the LASIK customer at the time when a belated manifestation of injury to the eye is diagnosed. If vision clouding problems appear, there may be no financially responsible defendant available against whom a plaintiff can obtain sufficient recovery. This is a particular problem when the longer-term cellular effects of today's LASIK eye surgery manifest themselves years after the surgeon has been paid.

   In part, this tort liability phenomenon of "no viable defendant to sue" reflects business practices that emphasize the very short term orientation of the coverage of malpractice insurance for ophthalmic surgeons. The malpractice insurance industry seems well protected by its preference for "claims-made" policy coverage, the dominant form of new coverage. Such coverage pays claims made during the years for which the insurance was in force. The coverage would not shield the individual surgeon when a claim about delayed corneal blurring effects is made long after the brief LASIK operation is over. This makes a difference for the plaintiff because the absence of an insurance carrier diminishes [*549] the prospects that the plaintiff will ultimately receive damages after a favorable judgment.

   V. The Medical Context

   What Long-Term Issues Exist After LASIK Surgery?

   LASIK is widely performed worldwide "despite the absence of thorough data on the healing response and long-term complications at the tissue level. Clinically visible complications . . . are relatively well known, but the underlying cell biology of these phenomena is less well understood." n35 One study found a loss of cells in a layer of the eye beginning six months after surgery, but the cause of this diminution is unknown and requires further research. n36 Corneal haze of several types "may degrade the retinal image" and more research is needed about its clinical impact. n37 These concerns are more long-term; issues concerning the flap of corneal tissue cut in the eye are among the near-term concerns of eye surgeons, as illustrated in American Academy of Ophthalmology publications. n38

   A frequently cited challenge for surgeons is "irregular astigmatism." When the same eye has been subjected to multiple laser surgeries to improve on conditions initially reported by the patient after surgery, "corneal stability in the long-term is still a worrying factor," and in individuals with a major degree of irregular astigmatism, loss of visual acuity is permanent and symptomatic. n39 Not all irregular astigmatism can be corrected; careful patient selection is often recommended. n40 The LASIK technique is too new for surgeons to understand the natural history of future effects of "central islands" on the cornea, which cause numerous detrimental effects. n41 For the estimated 165,000 photorefractive keratectomy (PRK) procedures done annually, "visually debilitating corneal haze may persist in approximately 5% of all PRK [*550] patients." n42 Enhanced cellular reflections from high numbers of wound healing keratocytes are an important contributor to haze, and drugs may be useful to aid clarity of vision after PRK. n43 Night vision deficiencies are "one of the main challenges" to improving laser eye surgery. n44 Corneal scarring and keratectasia, or dilation of the eye, were a particular issue with patients who had multiple LASIK surgeries, with cautions for surgeons about third and fourth retreatments of the same eye. n45 A Utah researcher/surgeon noted the "paucity of peer review literature" to substantiate LASIK's safety and efficacy and expected in a 1998 article that better computer software would reduce the percentage of patients who required retreatment-which was then at about thirty percent. n46 We simply do not yet know enough.

   VI. The Litigation Context

   Are Long-Term Effects Actionable?

   If a patient is dissatisfied with the resulting vision after LASIK, a second surgical procedure may be offered, but the literature cautions about more serious consequences with each successive cutting of the eye tissue. n47 Corneal perforation is rare, but other potential complications include ingrowth of the epithelial layer, infection, severing of the flap of skin cut in the cornea, wrinkling of the flap, and corneal astigmatism. n48 The longer-term effect of the surgery on cellular changes in the complex tissues of the eye is being studied, but time will tell whether the current favorable view of the surgery is altered by future studies showing eventual degradation in vision in a LASIK population compared to an uncut-cornea "control group." As of now, evidence is unavailable. There are indications that the collective profitability for surgeons performing the procedure may inhibit other doctors from rendering [*551] critical second opinions about LASIK. n49 Regardless, the cases that have reached litigation have involved a variety of vision impairments, including disabling impairments for persons who need excellent night vision, such as pilots. n50

   Whether the individual's impaired vision effects are worth litigating is a matter of judgment for the patient and counsel. The contingent fee system makes the plaintiff's counsel somewhat reluctant to challenge multiple defendants on a cause of action that does not yet have substantial case law illuminating the duty and liability of the manufacturer and surgeon. The population of persons paying for this elective surgery tends to be somewhat more affluent than average patients, and for some of them, perhaps a later experience of complications will stimulate the search for legal relief on a fee-paid hourly basis. Counseling such a client to initiate damages litigation involves a number of considerations, including the unavailability of insurance carriers for claims that are made several years after the surgery.

   The causes of action would include defects in LASIK equipment design, defects in the knife-like microkeratome used to slice the cornea, failure to adequately communicate risks to the patient, failure to adequately warn of the long-term effects observed in the LASIK medical literature, and, perhaps, claims of breach of express warranty that the procedure is "safe" for the eye of the patient. The bold and attractive promises being made in LASIK advertising by eye surgery marketing corporations, some of whom are publicly traded entities, n51 may give rise to express warranty claims n52 as well as claims against the individual surgeon or the surgeon's corporate entity as conventional malpractice claims. n53 Safety advances in the design of machines for laser eye surgery [*552] may have reduced the adverse effects that would have been seen with the earliest LASIK equipment, though an insufficient time has passed to form reliable statistical projections. An elaborate publicity campaign against criticism of LASIK has been launched by a trade group, funded by manufacturers using a national public relations firm. n54

   Plaintiffs confront numerous barriers, including the Daubert standard, n55 which allows equipment makers and surgeons to exclude the testimony of a critic of the LASIK device's use if that critic had not passed the scrutiny of pre-trial screenings. A climate for product design liability regarding inadequacy of pre-market testing of the machines may exist when future claims are brought. The makers of the expensive laser equipment are rapidly altering and upgrading their machines and software as the marketplace demands rapid responses to competitors' innovations.

   What Barriers to Recovery Exist?

   The first barrier to recovery will be time: if the now-reasonable balance of risk data and effectiveness were to shift against LASIK after five to ten more years of experience, the patient with blurred eyes must establish a causal connection to his or her present condition. The complexity of medical proof of causation would be formidable because many post-surgery events might have triggered the harm.

   Time also affects the viability of a damages claim by the impact of the statute of limitations on the ability of a plaintiff to sue for an effect that became evident long after the laser surgery was completed. A cause of action would arise either when the surgery was performed or when the plaintiff discovered the connection between the surgery and the plaintiff's presently deficient vision. Plaintiffs could claim that they sued within a reasonable period after discovering that a tort had been committed, this "discovery rule" in torts would halt the tolling of the statute of limitations. n56 But, the degree to which any belated discovery of blurred vision can be tied to knowledge of the surgery-injury connection will be very fact-specific. This is not an easy issue for the plaintiff to reopen, several years after surgery. State medical [*553] malpractice procedures form an additional barrier against the potential plaintiff's recovery. n57

   Effects of the Malpractice Crisis

   The second barrier will be a likely absence of malpractice insurance as a force for settlement. An immediately observable injury tied to malpractice can produce a sizeable claim and a large settlement, as demonstrated in a recent Colorado case. n58 But, LASIK's cellular effect on the eye, if it occurs in a patient, will take time to develop.

   Timing is everything when insurance coverage is at stake, and here it will be central to the plaintiff's attorney selecting the right contingent fee case to accept. There has been a significant rise in the use of "claims-made" malpractice policy forms, under which most medical malpractice carriers decline to pay claims that have not been presented to the insurer during the contract term or within a short "tail" thereafter. n59 This type of surgical malpractice policy contrasts with the "occurrence" policy covering the acts of the surgeon during the entire policy period, even if the claim is made after expiration of the policy years. n60

   The severe lack of profitability is driving some insurance carriers out of the medical malpractice insurance market. Aggregate 2001 industry statistics n61 show that about $ 10 billion was spent on health care malpractice insurance mechanisms in 2001, of which $ 5,586,584,000 was in insurance premiums. Loss ratios rose to 74.4% in 2000 from 54.3% in 1997. It is estimated that the malpractice insurance carriers' combined ratios of loss and expense exceeded 133% of the insurance carrier's income from premiums at the same time that income from [*554] investments was diminished by stock market declines. St. Paul Insurance Company quit the medical malpractice insurance market when its losses became too severe: in 2001, the major malpractice carrier lost $ 940,000,000 on medical malpractice coverage and halted all future policy renewals or new policies. n62

   If an adverse eye effect is only manifested some years after the surgery, the physician's carrier will decline coverage because the patient's vision deterioration claim was not presented to the carrier during the contract period of the "claims made" policy. The plaintiff is able to continue the suit against the corporate or individual entity that performed the service, but the likelihood of a major settlement payment diminishes without the presence of an insurance carrier at the negotiating table.

   Once the plaintiff's lawyer learns that no insurance coverage exists for the belated claim, the corporate structure of the eye surgeon becomes very important to the plaintiff's recovery efforts. n63 The corporate structures used to protect the surgeon's own assets in an LLC or professional corporation may have been dissolved by the year when litigation begins. The surgeon is quite likely to have imprinted the corporation's name on the documents to protect the surgeon's personal assets. Propensity of the LASIK surgeon's competitors to cut prices n64 and to reduce overhead leaves less residual cash for an insurance or loss reserve within the surgeon's LLC. In short, there may be no viable defendant left by the time the plaintiff determines that LASIK caused the vision problems.

   Effects of Consent

   Consent forms present the third barrier to the plaintiff. The attractive models in the LASIK advertisement and the terrific price claims for throwing away one's glasses will inevitably receive more visible space in advertisements for LASIK than the comparable visuals receive in prescription drug advertisements. That is because the surgical consent forms that contain the warnings only need to be presented at the time [*555] the buyer pays for the service. The FDA has jurisdiction over the advertisements for a prescription medical device and, although the FDA requires that warnings be stated for prescription drug ads made to consumers, it does not require the same communication about risks in LASIK advertising. n65

   The drafting of a surgical consent form is an art, at which defense counsel should excel. Surgeons have listened carefully to their defense counsel. If a LASIK surgeon is sued, the defense will argue that an ironclad consent form was executed by the plaintiff. The consent forms for laser eye surgery may be an extreme readability test for people who have selected one among several competing vendors for cheaper, faster and more efficient service for their eyes. The savvy surgical staff always has "one more form" to hand the patient to be signed. The person who has elected to get the surgery has probably signed the credit card receipt before signing all the other forms, including the surgical consent forms. The buyer of high volume elective surgery may be unaware that among the routine paperwork, the customer is signing away future rights by failing to focus on the consent forms. Breaking through this barrier to attack the failure to adequately warn will be a major inhibitor upon the willingness of the plaintiff's bar to take these cases on a contingent fee basis.

   Effects of Preemption Defenses

   The reader may expect that, even if the surgeon escapes liability, the device manufacturer is still an available defendant for a compensation claim. Alas, preemption of state tort recoveries by federal statutes is the fourth barrier to be faced by an injured customer. The United States Constitution permits Congress to govern interstate commerce. n66 Congress responded to a concern about medical device safety by regulating the interstate sale of medical devices. n67 At the time the specific authority to approve new medical devices was delegated to the FDA, Congress answered the device manufacturers' pleas by prohibiting the states from adopting "requirements" for medical devices that differed from federal "requirements." n68 In the 1976 Medical Device [*556] Amendments, Congress preempted states from imposing medical device requirements that are in addition to or different from federal medical device approval requirements. n69

   In two cases, the United States Supreme Court has interpreted the device legislation to shield virtually all manufacturers of innovative medical devices. The injured LASIK patient's compensation claim against a LASIK device maker is likely to be barred by the Supreme Court's interpretation of the Food Drug & Cosmetic Act n70 to prevent state verdicts asserting design defect claims against FDA- approved medical devices. n71 The plaintiff in a LASIK case against a manufacturer must overcome the legacy of the device industry's landmark victory in the 1996 Supreme Court decision Lohr v. Medtronic, Inc. n72 when combined with both the industry's successful effort to win 1997 amendments to the FDCA n73 and the 2001 Supreme Court industry victory in Buckman Co. v. Plaintiff's Legal Committee. n74 These efforts have collectively slammed the door on most causes of action for defective design of a medical device. n75 Suing the LASIK equipment supplier will be unlikely to succeed if the claim is related to design; claims of inadequate warning might also be blocked both by the FDA's specific product labeling approval n76 and by the patient consent forms, considering the breadth of wording in the pre-surgery consent documents that are routinely signed by LASIK patients.

   Effects of Market Volatility

   Finally, the medical device market is both global and volatile. Rapid changes in technology are altering the competitive landscape. Additionally, the manufacturers of LASIK devices are entering and leaving the market more rapidly than manufacturers in more conventional medical fields. n77 The marketplace of laser makers is [*557] rapidly evolving, with some of the makers of today's machines unlikely to be found in existence if cases arise several years hence, and others consolidating and merging assets, perhaps without retaining liabilities for past users of the equipment.

   It may be that the maker of the machine used in a 2001 surgery has disappeared entirely or is not doing business in the United States by 2011, when the LASIK customer learns that his or her serious vision problem was triggered by cellular changes in the aftermath of the surgery. Piercing the corporate veil is a rarity n78 and the device makers will presumably have acted within the law in their merger or dissolution of the corporate structures.

   Likewise, the physician who performs LASIK surgery as the agent of a corporation will seek to be shielded by the corporate form under state corporate laws, as occurred in a Pennsylvania LASIK negligence case. n79 The surgeon may attempt to structure the corporate shell as thinly as possible, so that the corporation or limited liability company can be terminated after a few years or will be insufficiently capitalized to pay judgments that arise from later-detected harms.

   The result of this litany of disappearing defendants is that the eye surgery purchaser of 2003 may be unable to gain compensation in 2013, if and when serious eye problems can be diagnostically attributed to the surgery. The maker of the device is shielded; the surgeon is shielded or the surgeon's corporation is dissolved; and the malpractice carrier is excluded by a claims-made policy format. Clairvoyance is not required to recognize that LASIK's future problems would bring calls for a legislative solution to the absence of compensation or remedy.

   VII. Solutions

   Suggesting a Pooled Reserve Solution

   A certain portion of those who claim a LASIK-induced eye deterioration will correctly attribute their harm to the surgery. Of course, for some injuries there is no compensation because an act of God or force of nature caused the harm: LASIK surgery, however, is the kind of expensive service for which the injured person will expect to be compensated should an unexpected harm occur. The adverse eye [*558] conditions will diminish occupational abilities for persons like airline pilots and will diminish the quality of life for all who depend on clear vision. Such harm would merit some form of compensation under tort law principles if the surgeon acted negligently, if the device the surgeon utilized was negligently designed, or if the plaintiff received inadequate warnings. But, the legal system involves the various limitations noted above, so tort law will deny compensation in most cases.

   Nature abhors a vacuum-and modern media and politics seem to abhor a remediless injured person. Federal compensation for mass injury situations is requested by victims and their advocates in numerous situations. But the actual passage of federal relief legislation is very rare. Agent Orange compensation to military personnel who had served in Vietnam n80 and swine flu vaccine for persons who developed a rare adverse effect are among the rare few. Relief by federal cash assistance to persons who had elective surgery is quite unlikely in this instance.

   The states can respond to future calls for compensation by requiring the insurance carriers who write surgical malpractice coverage to establish a sufficient reserve to be available for future claims. Perhaps in hindsight, such a reserve compensation pool should have been structured for asbestos and other chronic illnesses with belated onset. However, once the medical signs of future problems appeared for those products, the opportunity had passed. The later claims system has borne the higher transaction costs of that inactivity. A state insurance department imposing a surcharge on surgical malpractice policies could create the pool of funding, allowing for claims on the pool in future years to be adjudicated through the tort system, as it operates in the future. Claims for which a viable defendant or carrier exists would be required to be brought first against those viable parties.

   What Loss-Reserve Structure Could Work?

   In light of the probable unavailability of viable defendants for the compensation of longer-term LASIK injuries, as discussed above, this paper advocates the creation of a state-level statutory "risk reserve pool" to pay claims for which no other resources are available. The fund would be used as a limited compensation vehicle with a cap on individual benefits payable upon proof of the elements warranting compensation. Funding for the risk reserve would come from a required surcharge or supplemental coverage payment for the issuance of malpractice insurance covering physicians who perform elective, non- [*559] emergency eye surgery. The payments into the risk reserve pool would be made by the surgeons or their corporate structure, perhaps in the form of a state surcharge of fifty dollars per non-therapeutically indicated n81 eye surgical operation performed. The pool would be held by the state insurance department in escrow as a funding source for any future claims for compensation. If the funds were not the subject of claims for ten years, which seems unlikely given the size of the patient population receiving LASIK surgery, then the fund would dissolve with the surcharges returned to those physicians who "contributed."

   In the event that a LASIK patient's post-operative eye problems are persistent or appear at a point in time set in state legislation, claims would be made against the pool only if normal channels of compensation were foreclosed and only if the surgical event proximately caused the harm to the eye. The long-term negative consequences of these elective eye surgeries might manifest themselves after the plaintiff has found that the conventional routes of compensation, against malpractice coverage of the surgeon or against the device maker, are no longer available. The insurance excise charge would produce the "insurer of last resort" in the state insurance fund.

   Why a State Remedy?

   Since these surgeries are elective purchases of a medical service, n82 they have no federal Medicare cost consequence. These elective sur-geries are not paid for with federal funds, and are not usually provided as an employee benefit, so the federal rules that lead to ERISA pre-emption of state remedies are not likely to inhibit state legislators. At least one court has held that such surgery is not medically necessary but is elective. n83 The state primacy over such surgical activities will be mani-fested by state oversight of malpractice insurance terms and reserves n84 [*560] and by the medical licensure roles of the states. n85 The states that recognize a LASIK compensation issue would be free to employ their authority over insurance carrier policy conditions and loss reserves, as well as the state medical licensing powers over physicians practicing in this area of surgery.

   Of course, how the proposed LASIK injury compensation system will work is yet to be determined. State legislators will first have to hear from a constituency supporting compensation in numbers that can outweigh the power of the medical lobby and the LASIK machine manufacturers' probable defensive alliances. If the experience with HMO legislation in Congress is any indication, many legislators will undoubtedly approach the task of drafting remedial legislation with a pro-patient approach.

   The compromise legislation that ultimately passes may set a standard for recovery from the fund that requires exhaustion of other remedies before a claim can be made to the state fund. Simplified administrative hearings before an administrative agency physician or panel of physicians, attorneys and administrators might be convened. The hearing could be similar to a disability benefits hearing, without the transaction costs of adversarial litigation. Causation of the eye condition will be the major fact issue for the adjudicator or panel, as a delayed effect of damage to the eye could be causally attributed to the LASIK surgery only after close attention to the eye's present condition by an expert ophthalmologist employed as advisor to the panel. The plaintiff's expert would be expected to meet informal norms of qualification, less stringent than the constraints on expert testimony under the Daubert n86 test or other state-law tests of expert witness testimony. Proof of causation could be somewhat relaxed in claims against the fund, perhaps with a set of presumptions concerning the vision deterioration effects of eye surgery and of aging as causal factors, when the legislation establishing the compensation scheme is created.

   The hearing could determine the current amount of eye impairment compared to an age-appropriate eye functions grid, fix the percentage of such current eye condition attributed to the LASIK surgery, and then determine whether another source exists from which benefits would be accessible to the claimant. Payments from the state fund would not be available unless the administrative official in the state department of insurance found sufficient credible evidence from competent medical evaluators that the vision conditions in the patient's eye had been [*561] adversely affected by the results of the elective LASIK eye surgery and that the impairment of vision as of the time of a benefits application was causally attributable to the surgery. Awards could be set up to a maximum amount of compensation, perhaps $ 50,000. If there were a viable civil tort case to be brought, the compensation would not be pursued or might be deferred by the panel.

   Certainly, proponents of the relief legislation will argue for statutory presumptions that eye surgery caused the compensable deterioration while opponents of the statute, including eye surgeons and their malpractice carriers, will argue that the person who bought the elective surgery should be left with the consequences. The degree of relaxation of such proof of causation would likely draw intense debate in the state legislatures. The factual issue of causation based on competing expert testimony regarding the source of the eye deterioration will pose a tough question for the civil jury. If normal aging of the claimant's eye tissue exacerbated the adverse effects of the laser slicing of the eye, the expert will need to opine about relative percentages of causation attributable to the effects of the surgery. The standard of proof in a case involving an older adult with other health problems may be especially difficult for the plaintiff.

   VIII. Conclusion

   New issues suggest new solutions. While laser eye surgery seems today to have few near-term problems, the massive numbers in the target population and the vagaries of human optical problems will pose concerns for trial lawyers. Barriers to recovery, when and if problems are found, will be a challenge to the remedial system of the future. State legislative action and insurance regulatory decisions to establish a risk-pool surcharge may be the optimal means to assure that future claims can be compensated. Plaintiffs' trial counsel will have a role in the creation of this future mechanism for relief, which will entail a focused and intelligent effort for governmental assurance of remedies.

Legal Topics:

For related research and practice materials, see the following legal topics:

TortsMalpractice & Professional LiabilityHealthcare ProvidersHealthcare LawActions Against Healthcare WorkersSurgeonsInsurance LawMalpractice InsuranceClaims Made & Occurrence Policies

FOOTNOTES:

n1 See Diana Digges, $ 4M Award Over Laser-Eye Surgery Breaks New Ground, Law. Wkly. USA, May 27, 2002, at 24.

n2 The author thanks Spectrum Consulting and the media department of the American Academy of Ophthalmology for providing their January 2001 estimates, Spectrum Consulting Associates, 2001 Revised Estimate of the U.S. PRK/LASIK Market & Estimates of PRK/LASIK Breakdown.

n3 In addition to those who purchase LASIK procedures, approximately 165,000 others will purchase photorefractive keratectomy (PRK), another form of eye surgery designed to improve vision. Id.

n4 Oven v. Pascucci, 46 Pa. D. & C.4th 506, 509 n.1 (Pa. Com. Pl. 2000).

n5 A useful reference about LASIK safety is the FDA LASIK, at http://www.fda.gov/cdrh/LASIK/ (last visited Jan. 13, 2003).

n6 Peter Hersh et al., Photorefractive Keratectomy Versus Laser In Situ Keratomileusis, 107 Ophthalmology 925, 931 (May 2000).

n7 Of course, the wording of the advertisements vary with the particular sales approach offered. The emphasis remains on cosmetic appearance benefits, the easier alternatives to glasses, and the affordability of the surgery.

n8 Spectrum Consulting Estimates, supra note 2.

n9 Id.

n10 21 U.S.C. § 321(h) (1999).

n11 Id. § 360E(c) (2000); 21 C.F.R. § 814.20 (2000).

n12 FDA, Checklist of Information Usually Submitted in an Investigational Device Exemption for Refractive Surgical Lasers (Oct. 10, 1996), at http://www.fda.gov/cdrh/ode/2093.html (last visited Sept. 12, 2002).

n13 See FDA-Center for Devices & Radiological Health, Checklist for Filing Decision for PMAs (2001), available at http://www.fda.gov/cdrh/ode/checklist/pma.html (last visited Jan. 13, 2003).

n14 See, e.g. FDA, Center for Devices and Radiological Health Consumer Information: Recently Approved Devices, CDRH Consumer Information Recently Approved Devices at http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cftopic/mda/mda -list.cfm?list=1 (last visited Sept. 21, 2002).

n15 See FDA, Checklist of Information Usually Submitted in an Investigational Device Exemption for Refractive Surgical Lasers § 3.2.6 (Oct. 10 1996).

n16 FDA, Performance Plan 2002 § 2.6.1 Program Description, Context and Summary of Performance (2002), at http://www.fda.gov/ope/fy03plan/part2 med.html.

n17 FDA, Center for Devices & Radiological Health, LASIK Eye Surgery: What Should I Expect Before, During and After Surgery?, at www.fda.gov/cdrh/lasik/expect.htm (last updated Oct. 1, 2002).

n18 See infra Part V.

n19 Sigma-Tau Pharms. Inc. v Schwetz, 288 F.3d 141, 145 (4th Cir. 2002).

n20 21 U.S.C. § 352(f) (2000).

n21 See Colo. State Bd. of Med. Exam'rs v. Roberts, 42 P.3d 70 (Colo. Ct. App. 2001).

n22 See, e.g., $ 1,750,000 Settlement in Suit Arising from LASIK Eye Surgery, Verdicts, Settlements, & Tactics, July 2002, at 297; Misassembled LASIK Surgery Implement, 45 ATLA L. Rep. 328 (2002).

n23 21 C.F.R. pt. 803.

n24 http://www.fda.gov/medwatch/articles.htm (last visited Jan. 13, 2003).

n25 21 U.S.C. § 360i(b) (2000).

n26 The device user reporting section was partially repealed by Pub. L. No. 105-115, Title II, sec. 213(a)(1)(E), 111 Stat. 2347 (1997).

n27 The rapid increases in volume of LASIK surgeries "adds to the importance of identifying even small risks associated with these elective procedures." David O. Mazur et al., Retinal Detachment in Myopic Eyes After Laser in Situ Keratomileusis, 129 Am. J. Ophthalmology 823, 824 (June 2000).

n28 Restatement (Third) of Products Liability § 2 cmt. a (1997).

n29 A product that is defective and unreasonably dangerous will be addressed with strict liability even if the designer was not negligent. Restatement (Second) of Torts § 402A (1965); see also Restatement (Third) of Products Liability § 2 (1997).

n30 Restatement (Second) of Torts § 402A, cmt. k (1965).

n31 Id.

n32 Restatement (Third) of Products Liability § 6(c) (1997): A prescription drug or medical device is not reasonably safe due to defective design if the foreseeable risks of harm posed by the drug or medical device are sufficiently great in relation to its foreseeable therapeutic benefits that reasonable health-care providers, knowing of such foreseeable risks and therapeutic benefits, would not prescribe the drug or medical device for any class of patients.

n33 Id. at cmt. b.

n34 Id.

n35 Minna Vesaluoma et al., Corneal Stromal Changes Induced by Myopic LASIK, 41 Investigative Ophthalmology & Visual Sci. 369, 373 (Feb. 2000).

n36 Id. at 375.

n37 Hersh, supra note 6, at 932.

n38 See, e.g., My LASIK Flap Management Technique, Eye World (Aug. 2002), at http://www.eyeworld .org/aug02/0802p43.html (last visited Sept. 12, 2002).

n39 Jorge L. Alio et al., Selective Zonal Ablations with Excimer Laser for Correction of Irregular Astigmatism Induced by Refractive Surgery, 107 Ophthalmology 662, 670 (April 2000).

n40 Id. at 670.

n41 Yi-Yu Tsai & Jane-Ming Lin, Natural History of Central Islands After Laser In Situ Keratomileusis, 26 J. Cataract & Refractive Surgery 853 (June 2000).

n42 Torben Moller-Pedersen et al., Stromal Wound Healing Explains Refractive Instability and Haza Development After Photorefractive Keratectomy, 107 Ophthalmology 1235, 1236 (July 2000).

n43 Id. at 1243.

n44 Mihai Pop & Yves Payette, Photorefractive Keratectomy Versus Laser in Situ Keratomileusis, 107 Ophthalmology 251, 256 (February 2000).

n45 See Simon P. Holland et al., Avoiding Serious Corneal Complications of Laser Assisted in Situ Keratomileusis and Photorefractive Keratectomy, 107 Ophthalmology 640, 651 (April 2000).

n46 Thomas Clinch, Discussion, commenting on Howard Gimbel et al., Incidence and Management of Intraoperative and Early Postoperative Complications in 1000 Consecutive Laser In Situ Keratomileusis Cases, 105 Ophthalmology 1839, 1847 (Oct. 1998).

n47 See id. at 1847.

n48 Yuichi Hori et al., Medical Treatment of Operative Corneal Perforation Caused by Laser in Situ Keratomileusis, 117 Archives of Ophthalmology 1422 (Oct. 1999).

n49 Posting of letter No One Wins Unless Everyone Wins by Marguerite B. McDonald, Chief Medical Director, Eyeworld, on LasikInfoCenter website (1999) (copy on file with the University of Cincinnati Law Review) ("We are only starting to ride the enormous growth curve of LASIK in this country. There will be more than enough surgeries for everyone to benefit if we keep our heads by sharing information openly and honestly and by resisting the temptation to criticize the work of our colleagues when we are offering a second opinion to a patient with a suboptimal result.").

n50 See Digges, supra note 1, at 24.

n51 Attractive websites offering "safe" surgery include http://www.sightsolutions.com/index-dhtml.htm (last visited Feb. 21, 2003) (no claim is made that this site or others creates an express warranty; it is used for illustrative purposes only).

n52 Conceptually, eye surgery is a service rather than "goods," so the conventional treatment of express warranties under Uniform Commercial Code section 2-313 is available only by analogy.

n53 Laser eye surgery is a source of malpractice claims that have successfully asserted "conscious disregard for the rights and safety" of eye patients. See Siuda v. Howard, No. C- 000656, 2002- Ohio-2292, 2002 WL 946188, at *11 (Ct. App. May 10, 2002). Websites critical of LASIK present more reports of verdicts and settlements. See generally www.lasikdisaster.com (last visited Jan. 2003); http://members.tripod.com/lasik facts (last visited Jan. 2003).

n54 Ellen Dean Smith, New Campaign Aims to Tell the Truth About Laser Surgery, Eye World, at http://www.eyeworld.org/june02/0602p13.html (last visited Jan. 13, 2003).

n55 Daubert v. Merrell Dow Pharms., 509 U.S. 579, 592- 93 (1993). This doctrine is followed in seventeen states. See Joseph Eaton, Survival of the Fryest, 30 Prod. Safety & Liab. Rep. (BNA) 333 (Apr. 15, 2002).

n56 See, e.g., Kubrick v. United States, 444 U.S. 111 (1979) (requiring actions to be initiated within a reasonable time after discovery of the malpractice).

n57 These statutes place procedural restrictions upon the malpractice plaintiff and reduce the potential damage awards.

n58 Colo. State Bd. of Med. Exam'rs v. Roberts, 42 P.3d 70 (Colo. Ct. App. 2001).

n59 A major professional liability insurer explains the distinction: "A 'claims made' policy protects the policyholder against claims or incidents that are reported while the policy is in force, or during an 'extended reporting period.' The negligent act, error or omission must have also occurred during the specific time frame set by the policy." American International Group, Inc., Frequently Asked Questions, at http://www.aigdirect.com/small business/customer service/faq inde x.cfm? PageID=fq020#top (last visited Jan. 13, 2003).

n60 Experts in malpractice coverage estimate ninety percent of malpractice coverage is on a claims-made basis and assume that "in the next five years or so occurrence [policies] will all but disappear." E-mail from Jim Kelley, Coverage, Inc., to James O'Reilly, Visiting Professor of Law, University of Cincinnati College of Law (October 29, 2002 10:43:00 EST) (on file with the University of Cincinnati Law Review).

n61 The statistics are taken from A.M. Best reports and other sources, and were presented to the 2002 Annual Meeting of the American Bar Association by malpractice insurance experts. Theresa W. Bourdon, Address at the 2002 Annual Meeting of the ABA, Tort and Insurance Practice Session (Aug. 10, 2002).

n62 The St. Paul Companies, Inc., News, (Dec. 12, 2001) ("The St. Paul Announces Fourth-Quarter Actions to Improve Profitability and Business Positioning," press release of St. P a u l C o m p a n i e s ) , a t http://www2.stpaul.com/spc/corp/spcnews.nsf/6d54d5b37c9943cc86256 a64006eba96/c007bc65ef 4993c686256b200049e504?OpenDocument (last visited Feb. 21, 2003).

n63 Oven v. Pascucci, 46 Pa. D. & C.4th 506 (Pa. Com. Pl. 2000) (eye laser litigation against corporate provider of the surgical service).

n64 For example, in September 2002, a company called LasikPlus advertised laser vision correction for only $ 299 per eye. Genuine LasikPlus Laser Vision Correction: Now Only $ 299 Per Eye, Cin. Enquirer, Sept. 13, 2002, at D7 (on file with the University of Cincinnati Law Review).

n65 21 U.S.C. § 352(r) (2000) literally covers advertising for "restricted" devices, but in practice the broader class of prescription devices have been within FDA's advertising controls; see also 21 C.F.R. § 801.109.

n66 U.S. Const. art. I, § 8, cl.3.

n67 21 U.S.C. § 321(h) (2000). The LASIK machinery is classified as a medical device under federal regulations. See 21 C.F.R. § 886.4390 (2000).

n68 21 U.S.C. § 360k(a)(1) (1999).

n69 Id.

n70 Id. at § 360k (1999).

n71 See, e.g., Medtronic, Inc. v. Lohr, 518 U.S. 470 (1996).

n72 Id. (holding that 21 U.S.C. § 360k(a) preempted certain state tort claims).

n73 Pub. L. No. 105-115, 111 Stat. 2296 (1997).

n74 Buckman Co. v. Plaintiff's Legal Comm., 531 U.S. 341 (2001).

n75 See, e.g., Baker v. Medtronic, Inc., No. 2:99- CV- 1355, 2002 WL 485013 (S.D. Ohio Mar. 28, 2002) (holding that preemption precludes virtually all state tort claims against medical device manufacturers).

n76 The issue remains debatable for medical devices like LASIK equipment. Several courts have held that FDA clearance of a label does not preempt state tort cases for failure to adequately warn. See, e.g., Webster v. Pacesetter, Inc., 171 F. Supp. 2d 1 (D.D.C.,2001) (medical device); Eve v. Sandoz Pharms. Corp., No. IP98-1429-C-Y/S, 2002 WL 181972 (S.D. Ind. Jan. 28, 2002) (drug).

n77 Devices for laser eye surgery incur large development costs, making some companies vulnerable, with corporate survival consequences if the equipment does not achieve the desired results. See S.E.C. v. Schiffer, No. 97 Civ. 5853 (RO), 2001 WL 504860 (S.D.N.Y. May 11, 2001); see also In re VISX Sec. Litig., Nos. C-00-0649 CRB, C-00-0815 CM, 2001 WL 210481 (N.D. Cal. Feb. 27, 2001).

n78 This piercing would mean that parent or related corporations and successors might be held liable for injuries alleged to have been the result of a prior dissolved corporation's actions.

n79 Oven v. Pascucci, 46 Pa. D. & C.4th 506, 509 (Pa. Comm. Pl. 2000).

n80 38 U.S.C. § 1116(a)(1) (1991).

n81 A norm such as that used by Medicare for "medically necessary" surgical procedures would separate the aesthetic or convenience self-paid surgeries from those where eye surgery had been performed to respond to a medical need. "Under the Medicare Act, a physician's certification that the ambulance services provided are medically necessary is required before Medicare reimbursement is available." Howard Med., Inc. v Temple Univ. Hosp., No. 00-5977, 2002 WL 169380 at *4 (E.D. Pa. Feb. 1, 2002) (citing 42 U.S.C. § 1395n(a)(2)(2002)). Since this is not provided as an employee benefit, ERISA preemption is not likely to inhibit state responses.

n82 Steven Z. v. Kimberley Z, No. CN00-7918, 2000 WL 1658620 (Del. Fam. Ct. 2000).

n83 Stasack v. Capital Dist. Physicians' Health Plan Inc., 736 N.Y.S.2d 764 (A.D. 3 Dept. 2002).

n84 Federal ERISA recognized the primacy of states in regulating insurance within the states, and these malpractice insurance reserve issues are properly within the realm of state insurance departments. 29 U.S.C. § 1144(b)(2)(A) (1991); UNUM Life Ins. Co. v Ward, 526 U.S. 358 (1999).

n85 See, e.g., Colo. State Bd. of Med. Exam'rs v. Roberts, 42 P.3d 70 (Colo. Ct. App. 2001) (LASIK surgical malpractice led to state medical board disciplinary action).

n86 Daubert v. Merrell Dow Pharms., 509 U.S. 579 (1993).

A recent study on the effects of the excimer laser on corneal tissue: Joshua Ben-num (Tzriffin, Israel)

Photorefractive Keractectomy and Laser in situ Keratomileusis: A Word From the Devil's Advocate.

Archives of Ophthalmol. Vol.118, Dec.2000, p.1706-1707.

At a time when there has been a significant improvement in the technology of treatment of refractive errors by laser in-situ keratomileusis (LASIK), this author has issued a very timely warning both to patients undergoing the procedure and to the people performing LASIK.

The procedure involves a laser beam at 193nm that evaporates part of the cornea, breaking cells and molecules to create the smooth corneal surface necessary for best optical results.

The creation of free radicals, is an inseparable part of the cornea reshaping process.

Both photorefractive keratectomy (PRK) and LASIK are known to cause keratocyte apoptosis in the cornea of laboratory animals and hence, though there is no short-term damage, long-term damage must be considered.

These procedures are also known to have caused biochemical and ultrastructural modifications in the lens, both of which are markers of cataractogenesis. The vitreous base, located just posterior to the lens may be affected by the same process that affects the cornea, anterior chamber and the lens. Free radicals damage the vitreous collagen, leading to vitreous liquefaction. They have also been shown to promote tumours.

PRK might initiate a cascade of events leading to slowly developing abnormalities of the cornea, lens, vitreous retina and choroid.

On one hand there is a marked increase in the popularity of LASIK promulgated by massive advertisement. Hence there is an urgent need for intensive research into the potential threats to ocular function caused by LASIK which may occur in patients decades after the initial procedure, slowly but almost surely.

 

Fatal Focus, a novel by Jonathan Maxx

 

The long-term effects of photorefractive eye surgery remain unknown. It’s clear that LASIK and other forms of eye surgery using the excimer laser are not as promised –“quick, painless and effective.” And we know that some people will never recover their vision, lost as a result of this next “miracle of modern medicine.” If, after ten years, we look back and see that laser eye surgery was simply a mistake, a risk-prone procedure imprudently pushed for the sake of the money to be made, it will indeed be a sad day for the medical profession. However, might there be an even greater evil lurking?

The excimer laser is a source of ultraviolet radiation, a form of energy closely associated with mutagenicity and carcinogenesis. For more than a decade, researchers have questioned whether this laser-generated radiation might trigger the growth of cancer in human tissues. A clear-cut answer has never been obtained.

While some researchers proclaim that the 193 nanometer argon-fluorine laser does not produce radiation in the known mutagenic wavelengths, (the blanket statement that even the primary radiation from the 193 nm laser is entirely safe is not presently accepted by all researchers), and therefore cannot be mutagenic, others have pointed out that the interaction of human tissues with laser radiation causes the radiation to change— changing its wavelength into the mutagenic ranges. What is the effect of this “secondary radiation?”

Consider the facts. Last year over 800,000 people underwent laser refractive eye surgery. In each instance the patient’s eye was irradiated with ultraviolet radiation. The secondary radiation produced during the photoablative process has the potential of scattering into the surrounding tissues. Since this secondary radiation falls into the known mutagenic ranges, these tissues may be genetically altered by this radiation, and some cells may become malignant. If only one-half of one percent of those 800,000 patients sustained DNA damage—that may be as many as four thousand people whose lives are NOW threatened by the onset of cancer.

There is practically no research being conducted into the long-term effects of laser eye surgery. Is there a lack of interest? Or, is it more a matter of the ostrich hiding its head in the sand? At this time more than 1 million people have been prompted to undergo laser eye surgery. If laser radiation triggers cancer it may become apparent soon. (Alternatively, the histopathological effects may mimic the effects of x-ray exposure, and become apparent after several years.) However, determining the existence of a correlation between photorefractive surgery and cancer depends entirely on whether or not researchers are looking for it.

Jonathan Maxx is the author of the fictional novel entitled, “FATAL FOCUS”, which follows the lives of two physicians attempting to publish research about the potential deadly effects of the excimer laser. A portion of the proceeds from this book will go to long-term research concerning laser eye surgery.

Available by e-mailing the author, Jonathan Maxx.

Bibliography

Gebhard, E., Lang G.K., Tittelbach, H., Rau, D., Naumann, G.O. (Institut fur Humangenetik, Universitat Erlangen-Nurnberg) “Chromosome mutageniticy of a 193 nm Excimer laser” Fortchr Ophthalmol 1990; (3):229-33

Green, H., Boll, J., Parriesh, J.A., Kochevar, I.E., Oseroff, A.R.

“Cytotoxicity and mutagenicity of low intensity, 248 and 193 nm excimer laser radiation in mammalian cells.” Cancer Res. 1987 Jan. 15, 47 (2) : 410-3

Kochevar, I.E. (Wellman Laboratories, Mass. General Hosp., Boston) “Cytotoxicity and mutagenicity of excimer laser radiation.” Laser Surg. Med 1989; 9(5): 440-5

Lubatschowski, H., Kermani, O. (Institut fur Anewandte Physik, Universitat Bonn.) “193 nm Excimer laser photoablation of the cornea. Spectrum and transmission behavior of secondary radiation.” Ophthalmologe 1992 Apr: 89(2): 134-8

Muller-Stolzenburg N., Schrunder S., Helfmann, J., Buchwald, H.J., Muller, G.I. “Fluorescence behavior of the cornea with 193 nm excimer laser irradiation.” Fortschr Ophthalmo; 87(6): 653-8 1990

Phillips, A., McDonnell, P.J. (Doheny Eye Institute, Los Angeles) “Laser-induced fluorescence during photorefractive keratectomy: A method for controlling epithelial removal” Amer. Jour. Opht. 1997 123; 42-47

Seiler, T., Bende, T., Wincker, K., Wollensak, J. “Side effects in excimer corneal surgery. DNA damage as a result of 193 nm excimer radiation” Graefes Arch Clin Exp Ophthalmol, 1988; 226(3): 273-6

Trentacost, J., Thompson, K., Parrish, R.K., Hajek, A., Berman, M.R., Ganjei, P. “Mutagenic potential of a 193 nm excimer laser on fibroblasts in tissue culture: Ophthalmology; 94(2): 125-9 1987

Email Author

J Cataract Refract Surg. 2004 Sep;30(9):1861-6.

Bailey MD, Mitchell GL, Dhaliwal DK, Wachler BS, Olson MD, Shovlin JP, Pascucci SE, Zadnik K.

Ohio State University College of Optometry, Columbus, OH 43210, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

 

PURPOSE: To evaluate the reasons patients who have had laser in situ keratomileusis (LASIK) recommend it to others and examine the disparity between high levels of satisfaction and patient reports of night-vision symptoms and/or dry eye after LASIK.

 

SETTING: Northeastern Eye Institute, Scranton, and the University of Pittsburgh, Pittsburgh, Pennsylvania, and the University of California at Los Angeles, Los Angeles, California, USA.

 

METHODS: Questionnaires assessing symptoms and satisfaction after LASIK were mailed to 2,100 patients. The questionnaires included items about night-vision symptoms and satisfaction and an open-ended question for patients to give their reasons for recommending LASIK to others. The open-ended responses were categorized and tabulated.

 

RESULTS: Four hundred thirty-four patients provided reasons for recommending LASIK to others. Sixteen categories of reasons were identified. "No more spectacles/contact lenses" was listed by 180 patients (42%), followed by "better vision" (21%) and "convenience" (15%). Women were significantly more likely to cite "better comfort" (27 women versus 3 men; chi square = 8.99, P =.003) and "better quality of life" (41 women versus 9 men; chi square = 7.36, P =.007) as a reason for recommending LASIK. Of the 35 patients who reported dissatisfaction with post-LASIK vision, 20 (57%) would recommend LASIK to a friend because "LASIK helps others."

 

CONCLUSIONS: Categories of reasons for recommending LASIK to others were similar to reasons given by patients for seeking LASIK. Some patients who reported dissatisfaction with their vision said they would recommend LASIK, suggesting that recommendation of LASIK to others is not necessarily a measurement of the quality of a patient's vision after LASIK.

SOURCE

Although promotional, this study was still done by Synovate

Excerpts from the full text:

CHICAGO, Oct. 14 /PRNewswire/ -- Nearly 1 in 3 Americans have complained of under or over correction in one or both eyes, loss of quality of vision, vision fluctuations and poor vision in dark conditions, after undergoing Lasik surgery. The survey conducted by Synovate and commissioned by NeuroVision Pte Ltd, also found that of all Americans who experience these conditions, those in the South and the mid-West, like Chicago, are more likely to have a second Lasik operation, compared with other regions.

"As Lasik is an invasive surgery performed on a very delicate part of the eye, potential problems may arise as a result of the operation," said Prof. Donald Tan, Director, Singapore Eye Research Institute, Deputy Director Singapore National Eye Centre. "Lasik has been an invaluable tool in vision correction, reducing refraction in patients by a significant percentage but it is not without its drawbacks."

1 in 3 respondents who encountered post-Lasik problems still wear their glasses or contacts and 1 in 7 of all respondents underwent a second Lasik operation.According to the survey, women are nearly three times more likely than men to undergo Lasik but men were more likely to complain and are twice as likely to be disappointed with their Lasik results complaining of over or under correction and poor night vision.

(1) Population of the United States (2005) - 295,734,134 (Source: CIA World Fact Book). Extrapolated numbers: Completed Lasik - 13,308,036 (4.5%); Did not feel satisfied - 2,209,133 (16.6%).

BACKGROUND -- A Synovate eGage, a bi-weekly online omnibus that surveys a nationally representative sample, was conducted between 3 October 2005 and 11 October 2005. The total number respondents for the Lasik questionnaire were 9,495, with 428 who responded "yes" to having undergone Lasiksurgery.

LIKELIHOOD TO UNDERGO LASIK

-- Women are nearly three times more likely than men to undergo Lasik

- Out of total number respondents who responded "yes" to having undergone Lasik surgery, 314 female versus 114 male.

-- People in West, like California, were most likely to undergo Lasik - 5.3% versus 3.6% (East), 4.4% (Mid-West), 4.6%(South).

VISION PROBLEMS FROM LASIK

-- 32.2% or 1 in 3 Americans suffer from an under or over correction in one or both eyes, loss of quality of vision, vision fluctuations and poor vision in dark conditions.

 

DISSATISFACTION WITH LASIK

Geographical region

-- More than two million Americans are not satisfied with the results of their Lasik.

- Population of the United States (2005) - 295,734,134 (Source: CIA World Fact Book). Extrapolated numbers: Completed Lasik - 13,308,036 (4.5%); Did not feel satisfied - 2,209,133 (16.6%).

-- Americans in the East are least likely to be satisfied with the results of their Lasik. - 77.5% (East) versus 79.9% (South), 86.5% (West), 89.7% (Mid-West).

Age group

-- Americans 18-29 years old were less satisfied with their Lasik than other age groups. - 66.7% (18-24 years), 68.0%(25-29 years) versus 70% satisfaction and over for other age groups

Gender

-- Men are almost twice as likely to be disappointed with their Lasik results and mainly complain of over or under correction and poor night vision. - 7.9% (men) versus 4.8% (women) were somewhat/very dissatisfied. - Men complained about over or under correction - 16.7% (male) versus 11.1% (female) - Men complained about poor night vision - 20.2% (male) versus 19.7% (female)

ACTIONS TO CORRECT THE PROBLEMS

Re-doing Lasik -- 1 in 7 had to re-do Lasik - 15.2% underwent second Lasik enhancement -- Men are more likely than women to re-do Lasik - 18.4% (male) versus 14.0% (female) -- Americans in the Mid-West and South are most likely to have a second Lasik operation - 17.2% (Mid-West), 20.8% (South) versus 8.3% (East), 9.4% (West)

Wearing glasses/contact lenses

-- One-third who experienced common post-Lasik conditions still wear glasses/contact lenses - 33.3% still wear glasses/ contact lenses -- Women are 35% more likely to wear glasses/ contact lenses after Lasik - 37.9% (female) versus 23.7% (male)

Complaining about results -- Men are more likely to complain about the results - 13.2% (male) versus 9.0% (female)

SOURCE NeuroVision Pte Ltd

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Issuers of news releases and not PR Newswire are solely responsible for the accuracy of the content. Terms and conditions, including restrictions on redistribution, apply. Copyright © 1996- 2005 PR Newswire Association LLC. All Rights Reserved. A United Business Media company.

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Can J Ophthalmol. 2000; 35(4):192-203 (ISSN: 0008-4182)

 

 

Casson EJ; Racette L University of ottawa Eye Institute, Ont.  

We review the vision requirements for driving with the goal of revising current Canadian Ophthalmological Society (COS) recommendations for vision standards for driving. The report comprises two sections. In the first section we report the results of a survey of transportation authorities in Canada and the United States conducted on behalf of the COS to determine the current standards and medical review procedures. The results suggest that although the standards in Canada are more consistent than those in the United States, few of the standards in either country are evidence-based. In the second section we review the recent literature on visual function and driving. We conclude from this review that adequate contrast sensitivity is as important as, if not more important than, good visual acuity for driving and that there is little evidence to support a monocular standard for acuity, contrast sensitivity or visual field. Although there is evidence that the extent of a visual field defect is related to the ability to perform driving tasks, there is little evidence to suggest a relation between the location of the visual field defect and fitness to drive.

REFRACTIVE SURGERY UNTIL IT’S TOO LATE TO DECLINE

The importance of pupil size measurement, and anterior chamber depth…

“What good is making pupil size measurement a part of the standard of care if it is never utilized (by the doctor, or to communicate to the patient the risks it implies about the surgery they are considering)?

It’s a (kind of sick) joke.

Couple that w/the size of the correction AND with VERY deep anterior chambers (think about the notion of an ‘exit pupil’ taught in most classical physics classics as it pertains to optics – it is obvious that the farther away the ablation from the point of lens focus, the larger that ablation need be). Forget about it – I was guaranteed to have a miserable outcome.”

Patient , age 23, with smeared vision and debilitating dry eye as a result of Custom Vue LASIK on the VISX S4

"Last year, the medical journal Ophthalmology said the failure rate for eye surgery was one in ten, not the one in 1,000 figure widely advertised."

LASER EYE SURGERY FAILURE RATE REPORTED AT ONE IN TEN

http://news.scotsman.com/index.cfm?id=1395042004

 

"SCOTSMAN.COM"
Alison Hardie, Health Correspondent
Mon 6 Dec 2004


In part:

"Last year, the medical journal Ophthalmology said the failure rate for eye surgery was one in ten, not the one in 1,000 figure widely advertised.

 

The Medical Defence Union, Britain’s largest insurer for doctors, said negligence claims involving laser eye surgery more than doubled among its members since 1998. Which?, the organisation formerly known as the Consumers’ Association, has warned that people having the surgery are "gambling with their sight".

It found that some clinics did not highlight possible side-effects until after patients had signed up for treatment."

SMEARED VISION AND CHRONIC DRY EYE PAIN FROM CUSTOM LASIK DEVASTATES 21 YEAR-OLD

Another night indoors at apartment looking at a smeared TV set...and yet I can make out the letters on the TV just fine...most would say I have 'excellent vision' (as one neuroopthalmologist said)...if he was made to see like this he'd cry & scream bloody murder, & yet he makes & records comments like that...not much different than 9-10 months ago, when I spent my 21st bday 3days post-LASIK w/tremendous migraine headaches & a newly-smeared world, laying in bed w/compresses & closing my eyes trying not to look around...a pretty fun way to spend a 21st bday in a college town. They told me it would go away in a few days, then a week, then a month; that it was 'contrast sensitivity' and that it was perfectly normal; that there were 'frequently imperfections immediately following LASIK surgery'. (that everything being directionally smeared in the same direction in each eye was normal/ok/nothing to worry about!)

NEVER would I have imagined that nearly a year later I'd be worse - the vision would be the same (still uncorrected), I'd be out many thousands of dollars, that I'd spend all my time trying to get better completely futilely, that I'd have lost SO much time in my life & missed out on SO many experiences & that there would be NO end in sight, & that I'd soon develop eye pain (esp right eye) that would change my life even more.

Read these words from a physician who had LASIK last year

"I had "Custom Wavefront" LASIK on both eyes last January which puts me at about eight months. I have severe dry eye and had to have both my lower puncta cauterized three months ago.  I've also developed erratic visual acuity and loss of contrast sensitivity; glasses and contacts can't help since refraction for me is a moving target.  I also now have terrible accommodative dysfunction which no one seems to be able to explain.  I guess this generates a lot of the eye pain that I experience.

I am in a procedure-intensive specialty and I have some knowledge of the informed consent. The consent form offered up by most refractive surgeons is a sorry document which is guided by legal standards and doesn't give the patient realistic information by which to make their decision.  I fully believe that that constitutes malpractice in the setting of an elective procedure. There is also too much reliance on patient satisfaction surveys and not enough emphasis on real science.
Sure, if you were trying to market an expensive surgical procedure, glowing patient testimonials are better for the bottom line than evidence-based medicine. Not even a marketing 101 flunkie would submit a brochure which lists these real, possible outcomes...

- likely decrease in low light and night vision
- definite decrease in tear quantity and/or quality...no real way to estimate if 

  you will be symptomatic or not

- eye fatigue and/ or eye pain

- unpredictable quantities of metallic debris left behind
- permanent denervation or paresthesias of the cornea –retinal detachment or

  ischemia during surgery

If I would have suspected that any of the above outcomes were possible, I'd be sitting here right now CLEARLY viewing my computer screen with my old trustworthy glasses on.

Sorry for the long rant..I'm having a particularly bad "eye day"today."

Refractive Surgery is a Crime:
"I genuinely believe that RS [refractive surgery] is a crime in its present form.  LASIK maybe the worst of the offenders.  It "cheapens" the field of medicine and is perpetuated by greed.  I don't consider refractive surgeons colleagues...these people aren't healers.  I've also given lots of thought on how to reach potential victims of the RS industry.  At least patients deserve accurate information before making such a potentially life-altering decision."


 Complications waiting to happen:

"It's frightening to think of all the potential complications which haven't yet happened. There are thousands of people out there who will follow you and I into the [complications] heap ... patients that the ophthalmologists would like to forget... patients marketing types don't even consider when pressing out their glossy brochures. I really feel for these unsuspecting myopes. I'd give almost anything to have it back, to be in the pre-surgical decision phase.  Next best thing is to keep others from making the catastrophic mistake that I did."

Dryness and eye pain after LASIK:

"My conjunctivochalasis didn't exist to any degree before LASIK. With the severe dryness, my conjunctiva has thinned and degenerated and has now become an additional contributing factor to my eye pain."

Night driving:

"I'm still struggling with accommodation dysfunction and wild variance in acuity. Night driving is Hell. I've developed alternate routes to and from work based on day vs night driving. My night route puts me on the roads with the brightest street lights but is the least direct."


On anti-LASIK activism:

"Accidental altruism is what I call my experience. I couldn't save myself from the bad outcome, but I am determined to save others from it.  I see that in you. Sure, everyone is angry with bad RS outcomes, but it is clear to me that what sustains your passion is altruism. The only way to avoid degraded low light vision, weakened corneas, and dry eyes is -  "don't get LASIK!"  If you bury this procedure, you'll have created more healthy eyes than a city of ophthalmologists."
 

His LASIK outcome:

"I was using drops as prescribed every 1-2 hours for the first month. At month two, I had severe eye pain, shitty vision, and accommodative dysfunction. My lame refractive surgeon and lamer yet co-managing OD said these were transient symptoms. At month six, they basically abandoned my case because the transient nature of my symptoms seemed more tenacious than they were able to deal with. I found a better OD who tried everything to help with my accommodation problems. Reading glasses just gave me horrendous headaches. (I love to read and this "benefit" of LASIK has caused me great hardship). His diagnosis was irregular astigmatism, accommodative spasm with gross refractive fluctuations as a result of dry eye.
Christmas is tough. I'm coming up on my year anniversary of the char and scar, sometimes referred to as LASIK."

 ”Any Ophthalmologist performing LASIK is unethical by reasonable standards”:

The medical board answers to no one.... the board's function is to monitor, review and police substandard care and non-professional behavior of the licensed physican. As a medical professional, I can assure you that your butcher's actions are unethical.  Well, any ophthalmologist performing LASIK is unethical by reasonable standards."

Permanent eye strain after refractive surgery:


"I do find that eyestrain is now a way of life. The headaches get me down sometimes.The OR is brutal since the relative humidity is kept below 20% for infection control-so dryness is always an issue. I blast in a couple of drops of Freshkote before a case. My colleagues know about my ordeal with refractive surgery. I've managed to scare off a number of potential LASIK candidates who've asked if I was pleased with my results. My answer to that one usually renews their affection for their glasses or contacts."

A special place in Hell for refractive surgeons:

"I'm not religious by any means, but if there is a Hell, there is a
special place in it for Refractive surgeons. I've been trying to understand the phenomenon of LASIK surgery's tenacity despite all the clear indications that it should be abolished.
I believe that there are several key elements that refractive surgeons consciously or inadvertently exploit. First, we all hated our glasses and contact lenses. The promise of "perfect", unaided vision is so very seductive. The lure took away much of my objectiveness so I was hearing and reading only the propaganda and little of the real science. The dense marketing overwhelms the objective information on RS. Next, vision is poorly quantitated. Visual acuity is a subjective report by the patient..."yeah, one looks clearer than two...wait, let me see two again". No none really assesses how light is refracted by the anterior eye then interpreted by the retina and brain. The optics of the human eye are not static either. So the patient, ecstatic to be free of lenses, believes he or she is now seeing great just because the 20/20 line can be resolved without glasses. Never mind the loss of contrast sensitivity, loss of night acuity, loss of accommodation, corneal derangement, dry eye...........etc. Now you have a population of LASIK patients who want to believe their vision has been improved. They go on to be poster children for LASIK and tell their friends and the vicious cycle perpetuates. Those of us that get the complications are written off as unlucky bastards. Like the crazy aunt in the basement, no one wants to acknowledge us.


The FDA is not protecting the public from the refractive surgery industry:

The FDA is a joke. They obstruct good medications, devices and procedures and seem to bless the crap. Physicians on those panels are notoriously the bottom 5% of their medical school classes. Most couldn't critically read a peer reviewed journal if their lives depended on it. It may take a class action lawsuit to stop the butchering of eyes. [Deleted name of physician's lasik surgeon] is big here in [deleted city of surgeon's residence]...the TLC equivalent.
What about this- "LASIK special $499, red-tipped cane included!" Or maybe "LASIC- Lost Acuity Since I Came." It would get some righteous publicity.

Getting physicians to organize a campaign might be a start. Let's get the PhD's involved too.

I do have a wonderful wife who has helped me through all this. I don't think she can ever comprehend the magnitude of the damage LASIK has caused me. She has witnessed my decline into the darkest depression that I have ever experienced. I do understand what [deleted name of University of Michigan Psychiatrist who committed suicide in 2004 over his bad LASIK outcome] was dealing with. I believe that I came frighteningly close to his fate."

 
Lasik-damaged Physician contemplates life after LASIK:

"I was contemplating life in general today. It's amazing how drastically the LASIK has altered my life. I know you are experiencing that as well. I realize that for me, I'm waging two battles. The obvious one is the post-LASIK eye damage with all the associated treatments and daily misery. But possibly more debilitating is the way that this outcome has screwed up my psyche. At first, pure regret and anger wore me down until I was clinically depressed. Then medication helped me out of that dark state but I haven't yet regained my previous self. I still feel kind of dazed. Have you felt this?  It seems everything about my daily experience has recentered on my eyes and vision. If my eyes feel better one day, it's a good day. If I'm seeing particularly bad one day, getting through a day is Hell. Every activity from reading to driving at night reminds me of what I once had but have no more. I hate having my mental state and moods hard-wired to my eyes...know what I mean?"

"You are more than welcome to use anonymous excerpts from my emails. If we can save a single potential LASIK victim, we've given someone an
invaluable gift for life."
 
On Glenn Hagele:

”One of the things that really irritated me about USA eyes and LME was that idiot Glenn Hagle (sp.?) What a bag man for the LASIK industry. He tries to come off as some patient advocate but he shamelessly promotes the butchers. His stupid disclaimer "I am not a doctor" at the end of every posting should read "I am not in any way reputable." Patients with real injuries are simply referred to the "links". I watched a long thread where some guy with serious complications was communicating with Glenn. Glenn's advice was so pathetically worthless. Those generic "links" and canned advice Glenn was touting were going to get him nowhere, and might delay some needed intervention. Turns out that the guy was sitting on an overlooked retinal detachment. NICE!"

On people who won't express dissatisfaction with bad LASIK outcomes:

"Too negative," now that's rich. Someone nearly blinds you, curses you with unrelenting eye pain, and robs you of essential tears and you are angry? I wouldn't pay much attention to the lemmings. After all, they dilute the visible dissatisfaction with the procedure which allows more victims to be injured."

On LASIK suicide:

"It really sucks about your friend's vision. Her dry eye sounds miserable too. I know that pain all too well. LASIK will not only damage your vision and ocular health, it can be poison to your psyche. Her suicidal ideations ARE scary. I was there once. Looking back, I was dangerously close. By telling you, she may be seeking help. I didn't tell anyone. If she gets silent about it, it's time to worry."

More on LASIK suicide:

"Wow, the suicidal times seem like a dream now (nightmare of course). I was really thinking about driving over to the [Deleted name of LASIK surgeon] clinic in the early AM hours, putting a sign on the windshield;

"NICE RESULTS [surgeon name deleted]", and blowing my brains out with a pistol. The media coverage would've dinged the bastard pretty good. I actually had the sign made. I came so close it now gives me the creeps to think about it. You are the only one I've told that to. I'm like you though. There is a threshold of debilitation above which I will not accept.  That would be an unfair life sentence."

" I spent five months in the deepest, major depression.  Only in the last month have I felt that I might not end up as a suicide statistic. There were many, many nights where I would lie down in bed at night, hoping for an arrythmia or ruptured cerebral aneurysm to keep me from waking up to another day. Every morning when I drove to work, I wished for a big truck to T-bone me in an intersection...living was certainly more painful than dying.  I first though about inert gas asphyxiation with nitrogen, cheap, painless and easy. I thought about carbon monoxide but levels from new cars with catalytic converters isn't enough to give you more than a headache.
KCL, good if given through a central line, but caustic to veins...so you inject it in an arm vein and get pain and a quickly clotted vein. Later, I bought a gun, Glock 9mm. It was the knowledge that I would destroy my wife's life that kept me from aerating my skull. I was really messed up!

The one thing that the psychiatrists don't realize is that nothing follows you around like your vision. We are constantly reminded of the damage which wears your psyche down in the most effective, cruel way. It takes extra effort and strength to come up out of that type of depression."

On a movie theater experience after LASIK:

"My first post-LASIK movie experience sucked. I was in the nasty part of my depression and went to see that pathetic film "The terminal." The low light, ambient light aberrations were horrendous. I was so dizzy from them that I barfed thirty minutes into the flick."

On vision after LASIK and pain:

"My irregular astigmatism seems to be minimized when my eyes are moist with natural tears. If they are dry, my vision, day or night, stinks.
Night vision can be really bad with halos. Dryness also gives my a wierd haze during the day, as if I were looking through a glass of skim milk. The best artificial tears don't alleviate this regardless of how often I use them. Natural tears really resolve the haze. I still have constant eye burning, but it's now a 5 rather than myprior 9's. The accomodative spasm only occurs once a week or so, usually after reading or a demanding case at work. Reading glasses are a no-no. In an optimistic fugue a couple of days ago, I tried them on to read and was rewarded with a Godzilla of a headache and reallyblurred vision for about 24 hours."
----------------------------------------------------------------------------------------------------
After reading about what happened to this surgeon, do you still want LASIK?

The Promise of Refractive Surgery: A Promise Not Kept

An Insiders Journal on the Evolution and Misinformation of Refractive Surgery

Dedicated to:

And the thousands of others whose quality of life has suffered greatly as a result of

believing the professionally communicated promise of refractive surgery

Table of Contents

Section Page

Introduction 2

Refractive Surgery and Misinformation 3

Fundamentals of LASIK 5

·  LASIK’s surgical landscape: the Cornea

·  Asphericity and imaging of light rays on the retina

·  The loss of contrast sensitivity and quality of vision

·  Dry eye

·  DLK (diffuse lamellar keratitis)

·  Accuracy of the microkeratome

·  Enhancements and the use of misleading terms

 

Informed Consent 12

·  The absence of incidence data

·  A physician’s internally developed data

·  Physician use of manufacturer sales aids

·  Physician’s and conflicts of interest

·  Referrals to LASIK surgeons

·  Looking through a patient’s eyes

·  Websites

·  Recent FTC actions

 

FDA Approvals 16

·  Adverse events, complications, and visual symptoms

·  LASIK – an unapproved, off-label use of medical technology

·  LASIK – the initial & unusual FDA approval

o Day One

o Day Two

·  “Company Sponsored” LASIK PMAs

o Approval for the Bausch & Lomb Technolas™ 217A

Excimer Laser for LASIK

o University of Rochester Survey of FDA Approved

Lasers

Reported Patient Problems and Their Incidence 20

Discerning the Truth About the “Next Big Thing” 23

·  Wavefront guided LASIK

·  IntraLASIK™ (Intralase™ LASIK)

·  LASEK (an emerging off-label procedure)

·  Radio-frequency based procedures for hyperopia

·  Lens Based Refractive Surgery

o The ICL™ (implantable contact lens)

o The Artisan™ Lens

 

Summary 31

 

Appendix A 32

 

INTRODUCTION

The practice of businesses selectively using information to market products is widespread. Selectivity is a critical tool in marketing. But is it ethical in the marketing of therapeutic products and/or services in healthcare? Isn’t there more at stake when a manufacturer, a health system, and/or a health professional selectively uses information to move a medical or surgical therapy than when a business executive tries to move a product? Isn’t the obligation to tell the truth heightened when something to treat and possibly alter a person’s state of health is being proposed? Are not roles in healthcare clearly distinguished by their unique moral responsibility?

Unfortunately, the selective use of information in the marketing of healthcare products and services is rampant and growing. When I entered medicine years ago, the promise was to heal. Today, the promise of medicine has become money – to doctors, providers, and suppliers. This change in focus necessitates that we, as patients, more than ever, must take responsibility for our health.

But “Patient Power” in this changing landscape requires full knowledge, not a biased selection of facts. Knowledge that is unbiased, truthful, and complete. This puts the burden on the manufacturers, health systems, and healthcare professionals to provide patients with all unbiased, truthful information on expected costs, outcomes, and complications. Good, informed patient decisions cannot be made with selective information. Anything less than full disclosure is a disservice to the patient, the healthcare system, and society.

I have seen refractive surgery grow to 100,000 US procedures per year three years after 1978 introduction of RK (radial keratotomy). As long-term complications became known, it dropped to 30-40,000 procedures per year in the mid-1980’s. RK was reinvented in the early 1990’s emerging as “Mini-RK,” with shorter incisions and enhancements. It fell victim to laser based procedures in the mid-1990’s with the FDA approval of PRK, and then, the off-label LASIK procedure. Laser based procedures, mainly on the strength of LASIK, topped out at 1½ million procedures per year in 2000.

My concern for the patient has also grown with the introduction of each new procedure and the increasing numbers of procedures. The accuracy, breadth, and depth of the information used to move patients to a decision have been deficient. Concerns and knowledge on both outcomes and complications by the medical community have not been fully disclosed to an unsuspecting public. This is unacceptable as these procedures are elective, cosmetic, and irreversible.

Defense lawyers and doctors will point to a signed “informed consent” as proof that the patient’s are informed. But as you will learn, patients have been left out in the cold on key facts, and have been misled by clever copy. This began with the introduction of RK and has continued ever since. For instance, did RK patients, or even the more recent mini-RK patients, know that 40% of the corneas with RK after ten years were unstable and experienced progressive hyperopia? While evidence of these untoward outcomes were known in the late 1980’s, they were not communicated to patients.

Refractive procedures, with one exception, are permanent and irreversible. While permanence, at first blush, appears to be a positive attribute, it has a dark side – permanent problems, permanent outcomes, and no upgrades. The so called permanent correction (outcome) will not be so pleasing as one ages since the optical system changes with age. The required visual correction at one point in life may not be the desired correction later. Upgrades to improved or newer ways to correct vision will be ruled out since most of the present procedures involve permanent changes to the corneal structure (permanent removal of tissue). Those opting for these procedures are locked-in. Imagine being locked into a clunky 1980 car phone with no chance to upgrade to a newer, smaller, portable, feature laden, cell phone. I, like many who are interested, wear contact lenses and would like to be rid of them. But the question for me has always been at what risk? With what I know from surgeon’s private hallway conversations, I prefer my contact lenses, and will have them for some time. I will get rid of contacts when something comes along with these proven attributes:

·     minimal risk

·     great vision

·     no maintenance

·     allows prescription changes as my visual system changes with age

·    allows me to upgrade to newer procedures as they are introduced

·     reasonably priced

·     and allows me to undergo effective, proven therapies I may need as I age for glaucoma,

cataracts (IOLs), and macular degeneration. Then I will put my contact lenses aside, and become an enthusiastic refractive surgery supporter and patient.

 

”Letters to the Editor, Re: Corneal refractive power after myopic LASIK,” Ophthalmology,” September, 2003

(These letters refer to the difficulty of determining which IOL should be used in cataract surgery following LASIK. Since the cornea is now abnormal, there is some uncertainty on what should be done.)

Vahid Feiz, MD, Little Rock, Arkansas; Mark J. Mannis, MD, FACS, Sacramento, California

 

“The recent article by Hamed et al1 addresses an emerging problem that many ophthalmologists will be facing in the relatively near future. It has two main conclusions: (1) when manual keratometry and topography are used for intraocular lens (IOL) calculations after myopic LASIK, the power is underestimated, and (2) there is a direct, linear relationship between the degree of corneal refractive surgery and IOL power error as evidenced by regression analysis…What exactly is the source of error in determining true corneal power after keratorefractive surgery? The answer most commonly cited is the alteration in the relationship between the anterior and posterior corneal surface that results in a change in refractive index…In summary, the authors' conclusions and recommendations appear to verify the results of previously published studies.2,4 The most accurate method of calculating IOL power at this point remains use of refractive change induced by LASIK and a fudge factor to compensate for the change in refractive index of the cornea. In doing so, the relationship between corneal power and refraction needs to be considered...”

 

Douglas D. Koch, MD and Li Wang, MD, PhD, Houston, Texas

“We enjoyed reading Drs. Feiz and Mannis' letter and welcome the study of new approaches for calculating intraocular lens (IOL) power in patients who have undergone LASIK and photorefractive keratectomy. However, we do not feel that their letter accurately characterizes their method or the current state of knowledge regarding this challenging problem...

We are surprised by their comment that the clinical history method "still underestimated the IOL power." Asthey state in their article, none of these methods has been tested in a clinical series...Therefore, any comparative evaluation of these methods is purely speculation, pending further clinical study…the ultimate goal is the development of accurate methods of measuring true corneal power.”

 

REFRACTIVE SURGERY AND MISINFORMATION

Misinformation and hype in refractive surgery began with the introduction of RK and has followed a predictable pattern ever since. With the introduction of each new and/or improved procedure, the problems of older procedures, which were previously misrepresented or not even discussed, were made public. When “mini-RK,” an “improved” RK procedure, emerged in the early 1990’s, the real problems (and their probable incidence) of the “older RK” procedure were fully disclosed. The case for an improved procedure had to be made so that the new “mini-RK” would be adopted.

When the FDA approved PRK, the problems of the “mini-RK,” heretofore denied, were now openly discussed in light of an even better procedure. When LASIK gained momentum in the late 1990’s, PRK’s problems, again accepted privately but previously denied publicly, were publicly discussed to move surgeons and patients to LASIK. And with the introduction of laser-based procedures, new stakeholders - optometrists, manufacturers and emerging commercial refractive chains - joined the refractive surgeons in misinformation and hype. The “refractive surgery industrial-medical complex” was born.

We are now moving into the era of Wavefront, IntraLASIK, LASEK, and various intraocular lenses. LASIK, which surgeons, optometrists, refractive surgery chains, and manufacturers just three short years ago said had “1 in 10,000 problems”, “Throw your glasses away forever,” and “100% of the outcomes are 20/20”, etc., will now be beaten up with the unvarnished truth about its outcomes and complications. Unfortunately, the new and/or improved procedures will be marketed as LASIK was – with misinformation and hype. The truth on these newer procedures will emerge from the “refractive surgery industrial-medical complex” only when there is a need to obsolete them with “the next big thing”. And pay close attention to the spokesperson surgeons for the new procedures, they are the same people who hyped, with selective information, the procedures being abandoned.

 

Where have the Medical Societies been? Medical Societies need revenues to survive. They cease to exist without dues paying members and the financial support of industry. Industry provides financial support through medical journal advertising, medical meeting participation, and support to various causes vital to the member interests. Taking a stand, which can impact the revenues of an important member and industry group, can be difficult. One society did take a stand against RK in the early 1980’s and suffered. A lawsuit was filed and was successfully litigated against this society for interfering with the commercialization of RK

(free speech).

More recently in 2002, some surgeons, concerned with lawsuits, have discussed in their doctor-to-doctor web based chatrooms the blackballing of those doctors who serve as expert witnesses for plaintiffs. At the annual meeting of the American Academy of Ophthalmology in 2002, a Canadian surgeon, who testified in an Arizona malpractice case resulting in a $4 million judgment, was accosted by fellow US surgeons. His mistake was testifying for the plaintiff. Remarkably, this doctor had changed his view saying that he mis - spoke under oath at the jury trial. The ruling has been set aside and the case is waiting to be retried. Fear of retribution permeates the field of ophthalmology. Patient’s, with legitimate malpractice issues, now have difficulty finding an “expert” surgeon who will testify on their behalf. Rather than taking responsibility, refractive surgeons are shifting guilt to the patient and to those trying to help the patient. Misplaced guilt is not restricted to business and politics!

And where has the FDA been? While the FDA can regulate manufacturers, they cannot regulate doctors. Physician advertising is the responsibility of the FTC. This complicates the communication of accurate, nonselective information as cross-jurisdictional responsibilities dilute the effort.

 

“Vision Quest: Laser eye surgery has worked for millions but goes awry for 18,000 patients a year. A new

approach aims to fix that.” Mary Ellen Egan, Forbes, September 15, 2003, pg. 222.

“…Two years ago Heinbockel had a new kind of eye surgery called wavefront, approved by the Food & Drug Administration in October 2002…Though some 3.7 million Americans have had successful surgery since 1995, problems such as night vision, cloudiness, glare and halos occur in about 3% of patients – upwards of 18,000 per year. The new wavefront approach reduces flaws to just 1% of cases and fixes vision problems LASIK cannot…The procedure costs about $2,500 per eye, or 20% more than LASIK…But LASIK and wavefront are as different as ordering a suit off the rack and being fitted for a custom-tailored one… Thomas Wilson, 57, had two LASIK surgeries that left him with halos and night vision problems…His original LASIK doctors “thought I should be satisfied with my results,” he fumes.

 

“Lens-based refractive procedures offer advantages over LASIK,” William F. Maloney, MD, Ocular Surgery

News Europe/Asia Edition, September 2003

“The limitations of LASIK and other keratorefractive procedures are increasingly difficult to ignore. The aberrations inherent in corneal reshaping methods simply do not always allow the accuracy and predictability most refractive surgery patients have come to expect. Anatomical limitations (there is only so much cornea that can be ablated) combined with functional limitations (treatment zone vs. pupil size, etc.) have resulted in the realization that LASIK just cannot do it all, as many had hoped it would 5 years ago. The steady reduction in the amount of ametropia that can be reliably corrected with corneal refractive techniques has left surgeons looking elsewhere…the IOL has clearly emerged to fill this void… Lens -based refractive surgery also brings us back to basics, in the sense that surgical skill is a prerequisite to successful outcomes and satisfied patients. It seems to me that at least part of the appeal of LASIK and other corneal procedures was perhaps that they presented an opportunity to circumvent this basic issue, but this did not happen…

 

“Ten-Year Results on Radial Keratotomy Released,” National Eye Institute Information Office,

NEI Press Release, October 13, 1994

“…the study found that more than 40 percent of RK-operated eyes continued to have a gradual shift toward farsightedness. This finding suggests that some people who have RK may need glasses at an earlier age for poor close-up vision, a common problem after age 40, than if they had chosen not to have the surgery. ‘Based on these findings, it may be that some people will be pleased with their vision shortly after having RK, but their opinion may change five, ten, or fifteen years down the road,’ said Peter J. McDonnell, M.D., of the Doheny Eye Institute at the University of Southern California and the study's co-chairman. Today's findings, published in Archives of Ophthalmology, were issued from the Prospective Evaluation of Radial Keratotomy (PERK). The PERK study is the first large, well-designed clinical study to evaluate the long-term effects of radial keratotomy on the eye and vision.

RK is performed to improve poor distance vision, called myopia, which affects millions of Americans. For some people with myopia, RK offers the prospect of good distance vision without the need for glasses or contact lenses.

The surgery changes the shape of the cornea, the clear, rounded tissue at the front of the eye. It is performed by making spoke-like, partial-thickness incisions into the healthy cornea. These wounds cause the cornea to flatten, producing clearer distance vision. Today, about 250,000 RK surgeries are performed annually in the United States, up from 30,000 operations just five years ago. However, eye care professionals still have little scientific information about the procedure's long-term effects on the cornea and vision.

To provide these data, PERK clinicians periodically examined the eyes of the 435 participants since the study began in the early 1980s. Based on these examinations, researchers have published occasional reports in medical journals, including the results issued today. At the PERK's 10-year mark, researchers reported that RK effectively reduced but did not completely eliminate myopia in all patients. They found that 53 percent of the RK-operated eyes registered 20/20 vision, while 85 percent of the eyes had 20/40 uncorrected vision or better (required for a driver's license in most states). Approximately 70 percent of study participants said they did not wear corrective lenses for distance vision at the 10-year mark.

RK also had "a reasonable margin of safety," resulting in few vision-threatening complications. However, the researchers noted that 3 percent of operated eyes had poorer distance vision with glasses one decade after surgery, although none had corrected vision worse than 20/30.

Interestingly, the PERK scientists reported that 43 percent of the RK-operated eyes continued to have a gradual change toward farsightedness, called hyperopic shift. In fact, 36 percent of the eyes had become farsighted at the 10-year point…According to the researchers, this shift was detected in some affected patients as soon as six months after surgery and continued to progress a decade later. They said they do not know when and if this change will cease in the future. The scientists noted that the shift in vision was not related to the patient's age or post-surgical outcome. They added that they could not predict based on the PERK data which patients will develop the hyperopic shift. They did note, however, that the shift was more common in those who had RK surgery using longer incisions in the cornea, a common technique in younger and/or more myopic patients. Participants (in this study) were examined before and after surgery at two weeks, three months, six months, annually for five years, and again at 10 years.”

 

FUNDAMENTALS OF LASIK

LASIK has inherent problems due to the nature of the procedure. These problems occur whether $499 or $5000 is paid for the procedure. It has been frustrating to observe the “refractive surgery industrial-medical complex” position the higher priced procedure as providing better outcomes and fewer complications. There are no unbiased scientific studies to support this.

 

LASIK's surgical landscape: the cornea

Go to www.surgicaleyes.org for a complete description of LASIK and other refractive procedures. The cornea, the part of the eye operated on during LASIK, is the front most tissue of the eye. It is normally transparent and does not contain blood vessels. The cornea is only 0.5 to 1 mm thick, and is generally thinner centrally than peripherally. The cornea provides two-thirds of the eye's image focusing ("refracting") power. The other one-third is provided by the eye's internal lens, which is not involved in LASIK. The cornea has five layers, and two of these are very important in LASIK. The outermost layer, the epithelium, is a highly sensitive tissue about six cells thick. It acts as a barrier between the inner eye and the outside world, much as skin does for the rest of the body. It also provides a smooth surface allowing light rays to pass into the eye without being distorted. The epithelium has a bas ement membrane that helps it to adhere to the cornea's middle layer, the stroma. If the epithelium and/or its basement membrane are abnormal, the cornea may not heal properly, and an irregular surface and/or scarring may result.

The cornea's middle layer, the stroma, is the layer at which most of the LASIK procedure is performed. The stroma accounts for about 90% of the cornea, and is made up mostly of water and layered narrow bands of collagen/protein fibers. These bands crisscross the cornea and are under tension, much like the rubber bands in golf balls. The stroma consists of about 500 layers of these bands. Scarring in this layer can result in loss of corneal transparency.

LASIK makes the stromal layer thinner by removing tissue, and cuts through the collagen bands, severing them, to the depth of the flap. These bands never reconnect making the cornea both weaker and nonhomogeneous.

Enhancements make the cornea thinner and sever more collagen/protein bands . The severing of the bands allows a surgeon to lift the flap years after the procedure. The cornea is sealed around the periphery (minimal risk of infection) but never heals to its original anatomy. One of the biggest unknowns is what happens over time to the weakened cornea. It is under constant outward pressure from the intraocular pressure in the eye. Mechanics of materials would suggest that the cutting of the collagen bands would be a prime suspect in a serious complication called ectasia. Ectasia is the bulging of the cornea outward, and leads to progressive hyperopia and/or serious complications that may lead to a corneal transplant. How many LASIK’s would have been done if patients were informed that the flap never healed, that the cornea was no longer anatomically homogenous, that the cornea had been weakened considerably, and that the cornea was under constant outward stress due to intra-ocular pressure? How many patients know that this could lead to ectasia, an unnatural and unforgiving bulging of the cornea?

 

“Epithelial in-growth after laser in situ keratomileusis: a histopathologic study in human corneas,” Naoumidi I.

Et al. Archives of Ophthalmology, Volume 121, (7): 950-5, July 2003

Corneal epithelial cells lose their characteristic morphologic features and eventually degrade in the metabolically “unusual” environment of the flap interface. Concurrently, a capsule of connective tissue similar to scar tissue forms, separating them from healthy cornea.

 

“Histological and immunohistochemical findings after laser in situ keratomileusis in human corneas,” Philipp

WE, Speicher L, Gottinger W., J Cataract Refract Surgery, 2003;29(4):808-20.

This study, conducted in Austria, described histopathological and immunohistochemical findings in human corneas after myopic laser in situ keratomileusis (LASIK), followed by iatrogenic keratectasia and after hyperopic LASIK…Researchers concluded that the wound-healing response is generally poor after LASIK, which may result in significant weakening of the tensile strength of the cornea after myopic LASIK, probably due to bio-mechanically ineffective superficial lamella. After LASIK in patients with high hyperopia, compensatory epithelial thickening in the annular mid-peripheral ablation zone might be partly responsible for regression.

 

“Late-onset traumatic laser in situ keratomileusis (LASIK) flap Dehiscence,” American Journal of

Ophthalmology, April 2001

“ A 37-year-old male had bilateral laser in situ keratomileusis (LASIK) surgery performed on November 5, 1999 in Canada…On May 16, 2000 a tree branch snapped into his left eye…He noted an immediate decrease in vision and went to a local emergency room. The on-call ophthalmologist diagnosed a corneal flap dehiscence…Visual acuity, LE, was count fingers (CF at 6 inches)…the patients clinical status did not change over the next three months. This case has several interesting clinical lessons. Patients often ask when the LASIK flap will be finally healed. Since there is minimal wound healing except at the edges of the flap, given enough force directed against he cornea, the flap may become dislodged months and even years after uneventful surgery. Patients should be educated about this possibility and wear eye protection when performing potentially hazardous activities…This patient originally had low myopia and a photorefractive keratectomy (PRK) procedure would have been equally effective and obviously would not have led to this complication.”

 

“The Cornea is Not a Piece of Plastic,” Cynthia Roberts, PhD, Journal of Refractive Surgery, Volume 16,

July/August 2000

Page 409+. A conceptual model is presented in Figure 4 that predicts biomechanical flattening as a direct consequence of severed corneal lamellae. Rather than a piece of plastic, the cornea can be conceived as a series of stacked rubber bands (lamellae) with sponges between each layer (interlamellar spaces filled with extracellular matrix). The rubber bands are in tension, since there is a force pushing on them underneath (intraocular pressure), and the ends are held tightly by the limbus (the peripheral edge of the cornea where the clear cornea merges with the white of the eye). The amount of water that each sponge can hold is determined by how tautly the rubber bands are pulled. The more they are pulled, the greater the tension each carries, the more water is squeezed out of the interleaving sponges, and the smaller the interlamellar spacing. This is analogous to the preoperative condition in Figure 4A. After laser refractive surgery for myopia, a series of lamellae are severed centrally and removed, as shown in Figure 4B. The remaining peripheral segments relax, just like the taut rubber bands would relax once cut…This allows the periphery of the cornea to thicken. Postoperative corneal shape, and thus visual performance, is a function of at least three factors: the ablation profile, the healing process, and the biomechanical response of the cornea to a change in structure.

 

Letters, American Journal of Ophthalmology, Volume 130 Issue 2 (August 2000) Pages 258-259

"In the interesting article by R Lin and RK Maloney (Am J Ophthalmology) 127:129–136, January 1999), they confirm earlier reports that flap-related complications after laser in situ keratomileusis (LASIK) occur in 5.0% to 8.7% of cases…

Complications continue to be reported after LASIK, including unexplained delayed-onset keratectasia after treatment of moderate myopia…These reports indicate that LASIK weakens the structural integrity of the cornea and that the list of complications is as yet incomplete. We feel that fast and painless recovery after LASIK and the marginally better UCVA of 20/20 or greater may not outweigh the risks of this procedure in myopia less than -6.0 diopters…”

 

Letters, by Brauweiler, MD, Wehler, MD, and Busin, Ophthalmology, September 1999, pgs 1651-1655.

“It is my opinion that PRK and LASIK should not have been approved beyond 8.00 diopters. Beyond this limit many corneas will have had too much stroma removed to allow long-term stable vision. …Carmen Barraquer responded that 100% of eyes that had undergone similar thinning technique, known as myopic keratomileusis lost effective correction (in many cases up to 50%) over a twenty year period…Essentially what this means is that all eyes over 8 diopters that have their corneas thinned by laser surgery will result in significant return of their myopia…the main purpose of this communication is to alert patients to ask their patients physicians how much of their cornea is being removed before it is irreversibly vaporized.

 

“Iatrogenic Keratectasia Following Myopic LASIK of Between <4 and 7 Dioptres,” S. Percy Amoils, et al,

Poster, Annual meeting of the American Cataract and Refractive Surgery Society, Seattle, Washington, April

1999

”Results: The cases show progressive ectasia that developed from 1 week to 27 months after LASIK…Conclusions: LASIK surgery can cause permanent weakening and ectasia of the cornea even in low myopia…LASIK has certain intrinsic problems and the combination of incisional surgery and laser ablation has the potential for serious short and long term problems. Thinning and thus weakening of the stromal bed as well as the minimum strength inherent in the flap are the causative factors for the development of keratectasia.”

 

Asphericity and imaging of light rays on the retina

Think of the eye as a camera. Parallel light rays enter the eye through the transparent cornea. The cornea (and the eye's internal lens) then focus the light rays in much the same manner that the lens of a camera would, by bending the light rays so that they come to a single clear focus at a specific distance. This process of bending light is called refracting. In a normal eye, the cornea focuses light at a distance that produces a single sharp image on the retina, the neurosensory tissue that is akin to the film in a camera.

Light rays that are bent too little or too much do not focus at the correct distance, and a blurred image results from this refractive error. How much or little a cornea refracts light depends on the cornea's curvature. That is why refractive surgery seeks to change the refracting power of the eye by changing the cornea's curvature.

In nearsightedness (myopia), the cornea is too steeply curved, giving it too much focusing power and causing light rays to focus before they reach the retina. In myopia, the eyeball itself may also be elongated, contributing to the problem of light focusing in front of instead of on the retina. Conventional spectacle or contact lenses seek to optically decrease the focal power of the cornea, and thus correct the myopia, by placing a concave spherical lens (a "minus lens") in front of the eye. LASIK seeks to achieve the same result by removing tissue from the central cornea, flattening the cornea's overall curvature and thus reducing the cornea's focusing power. Exactly the reverse is true in farsightedness (hyperopia). Astigmatism is different from myopia and hyperopia, and it can occur concurrently with either condition. But changing the curvature of the cornea is not simplistic, as some make it out to be. The natural shape of the cornea is what the medical community calls aspheric which means that it is steeper in the center and flatter in the periphery. If one were to focus light rays from any angle outside the cornea, the aspheric shape would bend them so that they would fall in a small area on the back of the eye on the retina, called the “the center of least confusion.” This small area acts like a data collection plate for our human computer, the brain. The more data (light rays) that get to this collection plate, the more data the brain has to process for good vision. Since laser procedures get their effect by flattening the center of the optical zone, the cornea does not end up aspheric but oblate. After the procedure, the cornea is flatter in the center, and steeper in the periphery, causing light rays to fall outside the data collection plate. While this causes few problems in bright sunlight, since we do not need a lot of information to process a good image (much like a camera), it does cause problems as the Iris opens up seeking more data in low light or nighttime situations. Vision is not as sharp and is degraded. This can be demonstrated by testing for the loss of contrast sensitivity. Most, if not all, laser procedures today work by flattening the central optical zone creating the oblate (reverse of aspheric) surface. For Wavefront Guided LASIK (discussed later), an aspheric surface can be created, but it requires deeper tissue removal (and weakening) in the periphery.

The cornea has two surfaces that contribute to its refractive power, the front surface, which you see, and the back of the cornea, which you cannot see as it is inside the eye. It would be wonderful if these surfaces were uniform. If they were, then one could change the front curvature of the eye, in an aspheric shape, without concern for the back and its refractive power. Neither the front nor the back surfaces are uniform in their shape, which means that they are irregular. Therefore, cutting in the front, which is done at present, is not being done with the back surface taken in consideration. This can lead to refractive differences and/or uneven corneal thickness across the front of the eye. The thinner areas will be weaker than the thicker areas.

 

The loss of contrast sensitivity and quality of vision

Visual problems come with the creation of an oblate surface, uneven thicknesses, and with the transition zone from the flap to the untouched cornea. The most important diagnostic test for the quality of vision is the test for contrast sensitivity. Arthur Ginsburg, PhD, developed this test for the U.S. Air Force. The AF wanted to learn why some pilots who tested for 20/20 (quantity of vision) were missing objects while others who were 20/20 were seeing them with ease. The Air Force learned that the Snellen Eye test (black letters on a white background) is not a good test for vision quality. While one may see 20/20 after LASIK, and be counted as a LASIK success, one may actually have degraded vision. There can be a significant difference between the quantity of vision and the quality of vision.

Years ago, hearing tests were crude and involved the movement of a single sound frequency towards the person being tested. When the person heard it, hearing ability was determined - 20/20, 20/100 hearing etc. Researchers then realized that we heard sounds across a range of frequencies and this test-measured sound only at one frequency. The audiometer was then developed to measure hearing losses/gains across the full range of frequencies required for high quality hearing. If you were to suffer from a hearing loss, it would be described as a low frequency, middle frequency, high frequency or multi-frequency loss. And fortunately, tunable hearing aids are now available to amplify sounds in regions where the loss(es) exist. The full range of frequencies has also been translated into improving the listening pleasure of car radios, stereo systems, etc. Today we have the use of equalizers for audio sound allowing us to amplify selected frequencies (high, lows, middle range) for our listening pleasure.

Vision is very similar to hearing in that the quality of vision is not a function of one frequency but rather a range of frequencies. In the case of vision, these frequencies are spatial frequencies. The Snellen Eye Chart is crude and tests vision at one spatial frequency, providing woefully incomplete data on the quality of vision. The test for Contrast Sensitivity test measures vision across the full range of frequencies needed for quality vision, like the audiometer does for hearing. We know that any hearing frequency loss can interfere with the ability to discriminate what is heard. And we now know that any vision frequency loss can interfere with the ability to discriminate what is seen. This becomes particularly acute in low-light and/or nighttime situations, and explains why so many refractive patients like the vision they have in bright light but have significant difficulties in low light or nighttime situations. Bright light produces high contrast. Unfortunately, we do not have tunable eyewear to make up for these losses. For a much more complete description of contrast sensitivity, go to either www.surgicaleyes.org or www.vsrc.com (Dr. Ginsburg’s site).

 

“Post-LASIK changes in Corneal Asphericity,” Optometric Physician May 2003, (SOURCE: Anera RG,

Jimenez JR, Jimenez del Barco L, et al. Changes in corneal asphericity after laser in situ keratomileusis. J

Cataract Refract Surg 2003;29(4):762-8)

This Spanish study analyzed the origin of the changes in corneal asphericity (p-factor) after laser in situ keratomileusis (LASIK) and the effect of post-surgery asphericity on contrast-sensitivity function (CSF) under photopic conditions.

Clinicians measured the p-factor and CSF (best corrected before surgery and one, three and six months after surgery) in 24 eyes. They noted an increase in the p-factor after LASIK; there was an 87.2 percent change in the asphericity using the paraxial formula of Munnerlyn and coauthors. Other factors such as decentration, type of laser, optical role of the flap, wound healing, biomechanical effects, technical procedures and reflection losses of the laser on the cornea could account for the greater than expected increase (12.8 percent) in the p-factor. The CSF measurements deteriorated after LASIK; the change was significant in patients with myopia worse than -4.00D at frequencies of 9.2, 12, 15 and 20 cycles per degree. The increase in corneal asphericity after surgery, greater with a higher degree of myopia, and the deterioration in CSF with high myopia justify new ablation algorithms and further study of the variables that could modify the ablation unpredictably.

 

“Capriati troubled by night matches,” www.SportingNews.com , August 9, 2002

MANHATTAN BEACH, Calif. -- Jennifer Capriati is wary of playing night matches because the court lights

affect her ability to see the ball.

Capriati, the No. 2 seed, struggled for more than two hours before beating No. 16 Tamarine Tanasugarn of Thailand 6-3, 6-7 (3), 6-2 in the third round of the JPMorgan Chase Open on Thursday night. "Maybe I just started rushing a bit. I got thrown off a bit as soon as it was getting dark," she said. "I have problems playing at night. I was shanking some balls on my groundstrokes." Capriati, who had Lasik eye surgery two years ago, also had trouble picking up the ball in a night match at last week's Acura Classic, where s he lost in the quarterfinals.

"I feel like it's wearing off a little bit," she said of the surgery. At Manhattan Country Club, the light poles are low on stadium court. "At night, lights can start to become very bright," Capriati said, describing the effect on her vision. "When they're really low like that, it just feels like there's a flashlight on me constantly."

She didn't react well to the glare, double-faulting numerous times in the second set. "In the second set, I just stopped hitting the ball and she started really dictating the points," said Capriati, who was cheered on by her friend, actor Matthew Perry.

At most tournaments, the top players are required to play at least one night match to draw crowds. Having survived that obligation, Capriati said officials here know not to schedule her under the lights again. "I know there's going to be night matches, especially at the U.S. Open, so what am I going to do?" she said." For more on this, go to http://www.capriati.host.sk/a15_02.htm

 

 

ASCRS, 2000 Presentation by William Jory, consultant eye surgeon at the London Centre for Refractive

Surgery on Contrast Sensitivity.

Dr. Jory, in his study, found that Contrast Sensitivity was impaired in 58% of the patients who had LASIK – to the point that these people were not fit to drive safely at night. The Department of Health took this study seriously, in conjunction with a separate study at the University of Ottawa, and recommended that any patient who had refractive surgery should have a night driving test performed before a driving license is granted. Jory said that nighttime vision problems did not seem to be related to high corrections.

 

 

 

“Determining Medical Fitness to Drive,” published by the Canadian Medical Association in 2000.

In this booklet, laser eye surgery was added to the list of risk factors for unsafe driving. See Canadian Press Newswire for full press release, August 27, 2000. This recommendation was later overturned after pressure was brought to bear by the Canadian Ophthalmology Association.

 

“Functional Vision and Corneal Changes After Laser In Situ Keratomileusis Determined by Contrast

Sensitivity, Glare Testing, and Corneal Topography,” Jack T. Holliday, MD, MSEE, et al, Journal of Cataract

and Refractive Surgery, Volume 25, May 1999.

Conclusions: Functional vision changes do occur after LASIK. The optical quality of the cornea is reduced and asphericity becomes oblate. Changes in functional vision worsen as the target contrast diminishes and the pupil size increases. These findings indicate that the oblate shape of the cornea following LASIK is the predominant factor in the functional vision decrease.

 

Guest Editorial, Michael Mrochen, PhD, Department of Ophthalmology, University of Zurich, EyeWorld

Week, April 2001

“Refractive corneal surgery currently focuses on the correction of spherocylindrical errors as the most apparent and disturbing optical aberrations of the human eye. Unfortunately, a significant increase in higher order aberrations accompanies these corrections; thus, higher-order optical errors such as coma and spherical aberration have become more common…(this) correlates with a significant decrease in the quality of vision, especially under scotopic conditions.

 

“Inside LASIK – Screening the keratorefractive big picture show”, Maxine Lipner, EyeWorld, April 2001

Quotes attributed to James T. Schweigerling, PhD, Assistant Professor, University of Arizona… “Current refractive techniques, such as PRK and LASIK, dramatically increase aberrations in the eye.” After such procedures, a wave may look spherical in the center, but tends to deviate due to distortions in the corneal periphery. “What happens is light going through the edge of the pupil tends to focus in front of the retina, whereas light going through the center ..tends to focus on the retina. This gives you a multifocal effect…In areas with such spherical aberrations, patients can still see sharp points of light, but the contrast is reduced and images appeared blurred and hazy.” In effect, during the day, the patient sees very well however, as the pupil dilates, the error increases dramatically.

Quotes attributed to Leo Maguire III, MD, Associate Professor, Mayo Clinic… “It (refractive surgery) threatens public health to the extent that it degrades optical performance and impairs the public’s ability to perform visually challenging tasks.” Maguire also reminds practitioners of refractive surgery…that changes will occur in the eye with aging, independent of refractive surgery, and that patients in the keratorefractive market of today will grow old like everyone else. He is concerned about how well these patients with seemingly insignificant higher-order aberrations today will perform when their visual systems are later taxed by conditions, such as, early lenticular opacity, macular degeneration, and a decrease in psychophysical compensation. “By 2025, one in four drivers in the US will be over the age of 65…Patients with degraded night vision and increased glare present a danger, not only, to themselves, but to others who share the roadway.”

 

Dry eye

Dry eye occurs naturally with age. Temporary relief from dry eye comes from the use of artificial tears. For some, it means eye drops every few hours; for others, it means infrequent use of eye drops. Drug companies and the NIH (The National Institute of Health, our tax dollars at work) have spent millions seeking a cure, and, at the very least, developing possible treatments.

It is now known that LASIK causes dry eye in a large number of patients. When the flap is cut, the microkeratome cuts the nerves in the front part of the cornea. Some believe that these nerves never heal completely interrupting the communication between the nerves and the tearing mechanism. Others believe that the unnatural post-LASIK oblate shape hinders proper tear flow across the cornea. Regardless of the cause, many feel that dry eye is the Achilles heel of LASIK.

Many surgeons implant “punctal-plugs” in the ducts that drain the tears to alleviate the symptoms of dry eye. These plugs prevent the tears from draining. Sales of punctal-plugs have skyrocketed with the introduction of LASIK. For those who still need relief, artificial tears are prescribed. The sales of tears have also skyrocketed. LASIK has expanded the problem of dry eye from being a naturally occurring phenomenon to being a surgically induced problem.

 

 

 

 

 

 

DLK (diffuse lamellar keratitis)

DLK is classified as a “real” complication in the FDA classification system. Little is known about its cause

and its incidence may be much higher than what is being reported.

 

“Bilateral diffuse lamellar keratitis following bilateral simultaneous versus sequential laser in situ

keratomileusis,” McLeod SD, Tham VM, et al, British Journal of Ophthalmology, 2003;87:1086-1087

”…A retrospective non-comparative case series of 1632 eyes that had undergone bilateral, simultaneous or sequential LASIK between April 1998 and February 2001 at a university based refractive centre by three surgeons…The main outcome measure was the incidence of unilateral and bilateral isolated, non-epidemic DLK…Of 1632 eyes, 126 eyes (7.7%) of 107 patients developed at least grade 1 DLK. In six operating sessions, DLK was observed in more than one patient per session…CONCLUSION: In isolated, nonepidemic bilateral DLK, a similar incidence (of DLK) was observed regardless of whether the surgery was simultaneous or sequential, suggesting an underlying intrinsic cause for DLK.”

 

Accuracy of the microkeratome

Laser based refractive procedures were initially marketed to a wary public as space age technology with space age precision (laser accuracy is to the micron level). Since this was technology driven, not surgical skill driven, there was little to worry about. While surgeons today are trying to differentiate themselves by skill (to avoid price competition), the precision of the laser is still marketed as an attribute of the LASIK procedure.

What the “refractive surgery industrial-medical complex” does not talk about is the inaccuracy of the microkeratome that is used to cut the flap. If the desired depth of cut for a flap is 200 microns, the actual cut may be plus or minus 16-20% of this desired depth. The variation of the microkeratome has been a weakness of LASIK from the beginning. The creation of the flap, its depth, and its thickness are not only important to the visual outcome, but also to the potential for long-term complications such as progressive hyperopia and ectasia.

 

“Some foresee limitations in wavefront technology.” Ocular Surgery News, August 1, 2002

Noel Alpins, MD, said, “No matter how finely tuned a microkeratome is, it’s still a gross change to the cornea as opposed to the changes required with wave-front guided treatments.” The flap presents a problem.

 

Enhancements and the use of misleading terms

The term enhancement originated with the mini-RK in the early 1990’s. The mini-RK involved making a small incision RK followed by a waiting period. For those who had good visual outcomes, nothing more was done. For those that did not, another procedure was done that involved slightly longer incisions. If this too failed, another procedure followed with even longer incisions. Rather than call these re-operations, ophthalmologists created a patient friendly but misleading term, enhancements. The term has continued with all subsequent refractive procedures.

One of the problems with the term is that it sounds like the procedure is benign. Does enhancing make it better? This is a matter of semantics. For LASIK and RK outcomes that are under-corrected, more tissue is removed or deeper, longer incisions are made respectively. While in some cases, vision can be improved; permanent damage to the cornea is increased. For LASIK and RK outcomes that are over-corrected, tissue cannot be added back to the cornea nor can permanent incisions be reduced or eliminated. In short they cannot be enhanced.

These procedures are not as flexible as some would have you believe nor are they upgradeable. While the cornea is further flattened, it is also made thinner, and weaker by the removal of more tissue. Enhancement are a one-way street and are irreversible. Additional terms that are now finding their way into the vocabulary of refractive surgery include “Tear Savers” for the use of punctal-plugs (you still have symptomatic dry eye), “Advanced Surface Ablation” for PRK (once trashed, some are now trying to reintroduce it), “Blended Vision” for mono-vision (this is not like Varilux lenses where one lens is blended, but rather one eye is corrected to see far objects and the other eye is left untouched to see near objects), and most recently, “HD LASIK”, high definition LASIK (is it really high definition for all? all the time? for many years?). Each of these terms provides a message to the patient that is selective, and misleads.

 

INFORMED CONSENT

Patient informed consent while critical in all medical treatments takes on special importance in refractive surgery since patients are electing to undertake the risk of irreversibly altering an otherwise healthy eye. Information provided by advertising, promotional materials (brochures, etc), in-office staff, referring doctors, and the surgeon are all considered part of the legal informed consent. The truthful setting of expectations regarding potential outcomes and complications in all of these communication tools is crucial to making an informed decision.

Refractive patients seeking information on refractive procedures should know that doctors, their staffs, an referring professionals have been well schooled (“in-practice marketing skills sessions”) on how to handle difficult questions and concerns in an effort to keep interested candidates “in play” for the procedure. “Inpractice marketing” covers every contact the patient has with the practice. Training programs have been developed and offered by manufacturers to be given off-site or at the practice site. Many of these trainers/courses provide the doctor and his associates with tools to overcome patient objections. One of the pioneering laser manufacturers created their own teaching “University” to educate surgeons and their staffs The “University” goal was to increase patient throughput and profitability for the physician and the manufacturer (the manufacturer received $250 per procedure until 2000 when it was reduced to $100-150). The course was offered to those who purchased the company’s laser (a $450,000 purchase).

 

The absence of incidence data

The “Informed Consent” document was developed to provide a legal defense for doctors in the event of a lawsuit. It was also designed so patients would not be discouraged from the procedure. Many Informed Consents list possible adverse events, complications, and/or visual complications, including death (even though no one knows of anyone who has died from a procedure). And most do not list the incidence (how often something occurs) specifying only that a specific complication “may” occur. The inclusion of  significant life-changing event, death, that never happens, creates, by comparison, the perception that many of the other complications that “may” occur” are rare and “may” never happen as well. For full disclosure, informed consents must list the incidence of complications to insure. There is a big difference between “may” occur and a 20% occurrence rate when one is making an irreversible decision.

What would you do if you were told that a car you were considering “may” have a problem with the front brakes, and in the context of “may,” you were led to believe that it was 1%? What if it were 20%? 40%? You will see later in this document that the incidence of many refractive surgery problems warrant incidence percentages and not the word “may.”

Today, when having a refractive procedure with a FDA approved (excepting the first LASIK approval) Class III technology, manufacturers are required by law to provide booklets noting the incidence of each untoward effect. The doctors, in-turn, are required to include these booklets as part of the informed consent to prospective patients. Read the booklet carefully, and do not let anyone lead you to believe that the outcomes and incidence of problems will be any different. Some doctors will try to tell you that “his/her” patients do not seem to have these problems. Don’t believe it for a minute! A hangover from the first FDA laser approvals is that many of the original laser machines are still being used. These approvals did not have great incident data when approved, nor were the manufacturers and doctors compelled to provide FDA reviewed booklets to the patients. As a result, the vast majority of LASIK patients did not receive full and accurate information on outcomes and complications.

Going forward, interested parties should stick to data generated from FDA studies (excepting the original LASIK study) to insure that apples are being compared to apples. All FDA studies must follow the same format. Be wary of non-FDA studies that create expectations of better outcomes and/or fewer problems. Pay very close attention to the inclusion criteria (who can be considered a candidate). Data can vary according to the type and size of correction required. The data generated for the FDA approval relate to a specific, well defined population of people. For those who do not fit the study population, extrapolation of the results is problematic.

 

A physician’s internally developed data (personal studies)

Some doctors may show you his/her own data, collected from his practice on a refractive procedure, and say that his/her data is m uch better than the FDA data. Be cautious! Have my colleague put this in writing. The differences between a surgeon study and a FDA study are significant. FDA post-procedure exams take about three hours. And, a third party, who has no vested interest, must do post procedure follow-up exams. If a surgeon followed this rigor, he/she would lose control and money. They simply cannot afford the rigor required by the FDA in a commercial setting. A decision based on a physicians’ data is speculative at best.

 

Physicians’ use of manufacturer sales aids

When a doctor uses marketing materials, ask who developed the pieces, and ask if the FDA had approved the materials. The FDA has authority to insure that outcome and safety data from a manufacturer are provided accurately. Unfortunately, this is not true for physician developed marketing pieces. The FTC (Federal Trade Commission) has jurisdiction over physicians. Individual physicians are of little interest to the FTC so an interested patient must be on guard with non-manufacturer developed material. It even pays to scrutinize manufacturer materials, one well-known laser manufacturer created a physician sales support piece showing the comparison of several procedures. It was done in such a way that the competitive procedures were misrepresented. The FDA called them on it and asked them to desist. They, however, were not asked to recall the sales piece, so it was in use long after the FDA warned them. This type of marketing was done not for the benefit of the patient but for the benefit of the manufacturer.

 

Physicians and conflicts of interest

We have the problem of multiple conflicts of interest (payments, free use of lasers & equipment, travel) in the medical community. Surgeons are not immune. It is important for patient’s to understand what a physician’s and/or refractive surgery centers ties are. One doctor takes great pride in having no conflicts as he consults for all manufacturers, pulling in over $1 million per year. It is not what he does for his clients , it is what he does not do…like talk about the complications that beset each category of procedures. The “Informed Consent” should include all conflicts so those seeking opinions and/or procedures can discern the ties of the physician or practice to outside forces.

Medical opinion Leaders, medical publication authors, optometrists, surgeons, and manufacturers all are suspect. Since many of these people are conflicted, the patient must be responsible for demanding full disclosure. One way to insure disclosure is to have my colleague state in writing that he/she has received no

 payments (cash, equipment, trips, discounts) in kind from any manufacturer.

 

Referrals to LASIK surgeons

Many LASIK surgeons, LASIK centers, and National Chains have built their LASIK business on referrals. Most often these come from Optometrists (OD). Referrals generally involve payments to the referring doctor. Since kickbacks are illegal, a co-management arrangement is generally put in place. These payments, in the good days of 1998-2000, approached $1000/eye. An OD could make much more from one referral than several contact lens or eyeglass fittings. Today, with the economic downturn and reduced LASIK pricing, referral payments have been reduced, and in some cases, eliminated. This change raises some serious questions - ‘how much co-management was really being done?’ and ‘was co-management really a cover for a kickback” – which need to be answered.

If you are being referred, find out what the referral arrangement is, and find out how much the doctor has earned from referrals over the past three years. You may be dealing with someone who is seriously conflicted.

 

Looking through the patient’s eyes

The article that follows, which recently appeared in the New York Times (2003), addresses the issue of patient information and perception. It underscores the need for complete disclosure so patients can make an

informed decision. These situations are fraught with misunderstanding, particularly when many sources are involved with providing information.

 

“Seeing Risk and Reward Through a Patient’s Eyes”, Robert Klitzman, MD, New York Times, May 27, 2003

But more important, many doctors weigh the risks and potential benefits of treatments in ways different from their patients without realizing that wide contrasts exist. Risks, after all are relative: what one person considers too dangerous, another might not. The way risks are presented and framed shapes our perceptions of them…In research too, (medical) investigators are supposed to warn of possible dangers. Yet, at times, they minimize such hazards and promote only the benefits…According to research, humans do not always think rationally about risks…they see patterns where none exist…With a side effect, too, it is one thing to say that the odds of its occurring are 30 percent. But the importance or unimportance of that symptom may range widely between people in ways that doctors do not take into account. Doctors often have trouble dealing with the inadvertent, side effects of their own treatments.”

 

Websites

Patient information websites are sponsored by doctors, refractive surgery centers, independent physician groups (many who have a vested interest in one procedure or another), former patients, manufacturers, and

the FDA.

Surgical Eyes (SE) www.surgicaleyes.org is the best. Any person considering refractive surgery, as part of the informed consent, should be sent to SE during the consideration process. SE provides the other side of the story. It is a counterweight to the hype of the refractive surgery community (optometrists, surgeons, and manufacturers). Ron Link has done a real service for patients, and while some may disagree, he has done a service for the surgeons as well. The more the patient knows, even if it results in fewer procedures, the healthier the industry will be.

Misleading information characterizes most other websites and their chatrooms. Some website chatrooms have permanent contributors who post frequently as “independent experts”. Be careful, some of these are not independent and are deeply vested. Discernment falls squarely on the shoulder of the reader. A appropriate caution for all is to know whom the expert is, and to know what financial ties they have to refractive surgery. If the person is a physician that does the procedure, find out how many procedures he/she had done and his/her annual income level from refractive surgery.

The procedure history is also important. For most, a high number would indicate experience and expertise. For some of us, a high number would indicate the physician’s vulnerability as problems surface. One would expect the higher the number, the greater the emotional investment in believing he/she did the right thing, and the stronger the defense of his/her actions.

 

“LASIK complications and the Internet: Is the Public Being Misled?” Fahey, Weinberg, Journal of Medical

Internet Research, Vol. 5, No. 1, March 2003.

Conclusion: the quality and quantity of the information on the Web on the complications of LASIK are poor. More work is required to encourage clear, accurate, up-to-date, clearly authored, and well-referenced, balanced ophthalmic information. “The poor quality of the information represents a negligent omission, as the public are being misled into believing that LASIK is without risk,” Fahey concluded. “This may lead to liability cases by patients with complications whose decision to have LASIK was based on the information they read on the Web site.” Dr. Fahey said he believes that if a surgeon is responsible for the content of the site, he or she bears the burden to ensure that the information “is accurate, well-referenced and balanced.”

 

“Surfer Beware: Don't Trust All Online LASIK Info: Online LASIK info incomplete, study finds,” December 13,

2002

NEW YORK (Reuters Health) - Consumers who turn to the Internet for information about LASIK eye surgery should know it's a surfer-beware environment, according to a team of eye specialists who evaluated online information and reported their results Friday at the American Optometric Association meeting in San Diego,

California.

Dr. James O. LaMotte, a professor of optometry at the Southern California College of Optometry, Fullerton, and his colleagues used 10 search engines to find sites on LASIK…Next, using a 74-topic checklist derived from the Food and Drug Administration, the researchers then rated the sites for accuracy, awarding one point for accurate information on each of 74 topics related to the eye surgery.

Only 26% of the sites were rated as "markedly informative," with 28% moderately and 46% minimally informative, LaMotte said. A site had to contain at least 67% of the total possible points to win a label of markedly informative. The minimally informative sites contained less than 33% of the possible points. "What the LASIK Web sites did was tend to talk about the benefits of LASIK and to ignore the risks and contraindications," he said. Misinformation on the Internet is nothing new, LaMotte told his colleagues. Previous studies have found misleading or even harmful information disseminated on the Internet about fever in children and vascular surgical procedures. Other sites contain misleading information on age-related macular degeneration, an eye condition that can lead to blindness, LaMotte stated.

 

“ Medical Ethics and the Excimer Laser”, Samuel Pecker, MD, Archives of Ophthalmology, May 1997

”…the marketing required to achieve economic viability (of PRK laser surgery, and fits LASEK as well) is something that medical professionals are either uncomfortable with or would rather have someone else do.” ”This new technology and this new partnership (with laser companies) have the potential to create notable ethical problems, in such areas such as (1) agency, (2) conflicts of interest, (3) informed consent, (4) marketing and advertising, and (5) social issues – the relationship of medicine to society. At the least, rule 15 of the American Academy of Ophthalmology’s Code of Ethics would be observed. It reads, ‘Disclosure of professionally related commercial interests is required in communications to patients, the public, and colleagues.’

The marketing and advertising of PRK will put an increased burden on the ophthalmologist when it comes to informed consent because the cus tomer will come to the physician’s office with preconceived ideas obtained from the media and because the physician is assumed to be a trusted agent for a patient.”

 

Recent FTC actions

The US Federal Trade Commission (FTC) recently took action against two companies that were considered to be advertising unsubstantiated claims for LASIK. The actions, taken against The Laser Vision Institute and Lasik Plus, are the first of their kind.

Despite welcoming its moves, Ron Link, Surgical Eyes, is concerned that the FTC can only take action against national chains. “It’s a pragmatic position to take, but how does the local violator (your local doctor) get addressed? I don’t have an answer.”

 

FDA APPROVALS

By law, anyone bringing medical technology (device, instrument, etc.) to the US market must seek FDA approval prior to commercialization. The three classes of devices and required approvals can be found at the FDA’s website. Class III devices are generally the most innovative, having no precedent, and are the most regulated. A Class III device requires that safety and clinical data be provided to the FDA for analysis, prior to approval. The development of these data must adhere to guidelines issued by the FDA. Most (99%) of the submissions to the FDA are made by manufacturers seeking commercial approval of a product that they have developed or want to distribute. These are called company sponsored IDEs/PMAs. Companies must follow strict guidelines in the selection of their clinical investigators, the patients that enter the study, how the procedure is provided, and how data is collected before and after the procedure. The firs laser clinical studies which were for PRK (it does not involve the cutting of the corneal flap) were staged, with approvals for subsequent stages coming only after rigorous review of the previous stage, and took many years before completion of the third and last stage. In addition, the FDA required data from follow-up exams for up to two years before approval was even considered These studies, which were sponsored by companies, were required to have and did have high percentages of follow-up. These were over 95%, which means that 95% of their trial patients completed all of the required pre-operative and post-operative exams. These data were used to determine safety and efficacy. The higher the percentage, the higher is the confidence that the data truly reflects the outcomes and side effects.

Radial keratotomy (RK), which preceded PRK, did not require FDA approval. The device, a surgical scalpel, required for doing the procedure, was commercially available when the procedure was introduced in the US. Surgeons who wanted to provide this to the public were in business immediately. Unfortunately while the procedure was available, clinical data, and science-based information on outcomes/risks were not. Since this is what is considered an off-label use of a device/technology, the physician assumed full responsibility for liability.

 

Adverse events, complications, and visual symptoms

The FDA’s published refractive surgery clinical study guidelines establish three categories for the reporting of untoward consequences - adverse events, complications, and visual symptoms. The problem with this classification system is that patients with a serious “visual symptom” feel that they have a complication, a real problem. This classification methodology is not relevant to the consumer/patient and can lead to mischief. What will the patient be told when asking about complications?

When someone has significant visual symptoms - dry eye, loss of night vision, starbursts, etc. – their quality of life is truly impacted. Just go to www.surgicaleyes.com to their chatroom to see how much. A LASIK patient may be spending $1000 per year for artificial tears, may have given up driving at night, may suffer with fluctuating vision, may have a whole host of other problems, and may still be counted as a LASIK success. He/she only suffers from a visual symptom!

 

LASIK - an unapproved, off-label use of medical technology

Once the laser was approved for PRK in 1996, it became a candidate for any off-label use. Surgeons were free to use the laser as they saw fit. Prior to the PRK approval, surgeons outside the US (Italy, Greece, and Columbia) frustrated with some of the consumer unfriendly issues (pain, long term healing, and spontaneous corneal clouding) related to this procedure, began to apply both the laser and a device called th microkeratome. The resulting procedure becam e known as LASIK. LASIK seemed to be an improvement. It appeared to overcome many of the barriers (mentioned above) slowing the consumer adoption of PRK. Since the microkeratome was approved for another use and was already available in the US market, US surgeons were free, after FDA approval of the laser for PRK, to combine the laser with the microkeratome for LASIK. As with RK, though, FDA clinical data and science-based information on outcomes and risks were not available. (Some will argue that data was available from outside the US, but this was no acceptable science-based clinical data). US Surgeons initially limited LASIK to patients who required more than 6 diopters of correction leaving PRK for those who required less. PRK had proven to be problematic with higher corrections. They were also concerned about the long term effects of cutting the flap and felt that LASIK was warranted for those requiring significant corrections since they were handicapped when they were without corrective lenses.

 

LASIK- the initial FDA approval

Refractive surgeons early-on were concerned about offering an “off-label” procedure which put them at risk if anything should go wrong. The FDA, at the same time, was concerned about the growth of what was becoming a very popular unapproved “cosmetic” surgical procedure.

Surgeons met with the FDA to find a path for gaining the FDA’s approval. If successful, an approval would get them off the liability hook, and they could offer it as “FDA Approved.” The FDA wanting to get a handle on this fast growing procedure agreed to letting the surgeons sponsor a clinical study. The FDA agreed to review the data. The FDA would grant approval if the procedure were “proven” safe and effective. In reviewing the FDA Panel discussion and approval, one can only wonder why the FDA approved LASIK after a clinical study that was incomplete, had minimal follow-up, and did not meet the same rigor manufacturers were required to follow.

LASIK received its initial FDA approval in 1999, based on two physician-sponsored, not manufacturer sponsored studies – one for the VISK laser and one for the Summit laser. The manufacturers chose not to sponsor these studies - their products were on the market and expensive studies were not required to sell equipment. With an approval to sell, and with momentum building for LASIK, they needed to focus only on marketing, sales, and equipment service.

The FDA’s Ophthalmic Panel reviewed the two studies for approval in July 1999, three years after LASIK was introduced in the US and after several millions of LASIK patients. The transcripts of these proceedings are publicly available. They are PMA’s 990010 and P930034/S13 and are a most worthwhile read. The data used for the approval was deficient prompting key panel mem bers to abstain from the final vote. Below are some key excerpts and the panel votes.

 

Day One

PMA 990010 (VISX Star laser model C used with the Chiron ACS micro-keratome)

Page 42 - Follow-up or “accountability as shown here with 90.3% at 3 months, dropping to 76.3% at 6months….”

Page 67 – Dr. Pulido: “I would like some clarification from Jan Callaway about the patient accountability concerns and how she feels about the fact that there was 43 percent exclusion of the data”

Page 82 – Dr. Bullimore: “…The biggest is this issue of accountability…One characteristic of the PMA is the very variable accountability of these clinics. Overall the accountability is less than 75 per cent at 3 months and less than 63 percent at 6 months…So, the potential for patient bias or surgeon bias or investigator bias is considerable because of this at best mediocre accountability…The range of approval, also, has relevance to the question of corneal ectasia, and there are a number of reports and comments in the literature by very distinguished people in the field about the risk of corneal ectasia above minus 10…I would point out that the potential for long-term changes in refractive error still exist. Only going to six months would not, for example, demonstrate the long-term hyperopic shifts that we saw in the PERK Study (for RK).”

Page 89 – Dr. Pulido: “…but I have strong concerns regarding accepting the study as a whole because of the data set and if the FDA accepts this kind of study were accountability is only 57%, only because there was a large number of patients where will we stop?…the doctors should be chided for bad science..”

Page 92 – Dr. Yaross: “I think one of the messages that intended or not is sometimes perceived is that there are different standards for investigator-sponsored PMAs brought to this panel than for industry sponsored PMAs, and I think that is something the panel should be aware of.”

Page 96 – Dr. Ferris (National Eye Institute): “…and the fact that there is even the 15 or 20 percent missing inform ation when we have bars that say you cannot have more than 5 percent of this or 1 percent of that…that tells me that as you added more patients you are reducing the mean and suggesting that the missing information might be in the direction of more harm or at least less efficacy and that is the concern…”

Page 96 – Dr. McCulley (Panel Chairman): “In the guidance document there is a target, yes.”

Page 96 – Dr. Matoba: “Ninety percent, So, okay.”

Page 101 – Dr. Rosenthal (FDA): “…the guidance is guidance, and as you know the office has I think quite publicly stated that is general for the office of Device Evaluation an 80 percent level is generally acceptable of accountability.”

Page 143 – Dr. McCulley: “..so just for the data as presented does the Panel feel like there is sufficient follow-up for the correction of myopia with or without astigmatism in the ranges indicated?’

Vote – 2 were yes, six were no.

Page 147 – Dr. Ferris: “And I take it this is an issue because the guidance suggests 1 year (follow-up). Is that right?”

Page 182 – Dr. Van Meter: “...why are you unhappy with less than 90 percent data now when you have not been happy in the past?’

Page 190 – Dr. McCulley: “…All right, we have a motion on the floor for approvable with the conditions that have been read into the record, and it has been seconded…All those in favor of the motion, please raise your right hand high?”

On the vote for approvable, there were 9 yeas, 0 noes, two abstentions.

Page 192 – Dr. Macsai: “I abstained because there is a body of information out there that is in the scientific literature that has undergone peer review regarding this subject which provides knowledge regarding this procedure. However, I cannot assess that true safety and efficacy has been established due to the lack of accountability.”

Page 193 – Dr. Ferris: “I abstained from the vote because it is my belief that the data that were included I this PMA are not scientifically adequate for approval.”

The Panel Session ended with this recommendation to approve this LASIK application, with labeling conditions, as sponsored by the physician group. The uniqueness of this approval concerns itself with the low “accountability” and the short six months follow-up. No company would even be allowed to go to panel with data this inadequate. In the preceding fall, this panel recommended 3 year follow-up as a guideline for refractive IOLs.

 

Day Two

PMA P930034/S13 (Summit Apex Laser with unspecified microkeratome)

Page 100 – Dr. Kezirian: “ You will see that the PMA cohort has, at three months, an accountability rate of 89.6%, and at six months, 84 percent.”

Page 131 – Dr. Sugar: “We discussed this issue at very great length yesterday (VISX approval), and I don’t think it needs to be reviewed, but I think that the exclusion of sites that did badly is not an appropriate way to present data, either badly in accountability or any other regard.”

On the vote for approvable, there were 9 ayes, 0 noes, one abstention.

Page 172 – Dr. Ferris: I abstained from the vote of approvable with conditions, in part to be consistent, but also because I think in an issue of a degree of public health importance such as this, and where the side effects, statisticians always say compared to whatI believe with a follow-up of missing information of this magnitude, that I can’t adequately assess what that is…I am not a corneal surgeon…so I don’t want to vote against it, but neither do I feel I can vote for it.”

 

The panel session ended again with a recommendation to approve with conditions.

Unfortunately, the study as we shall see in future years was incomplete and flawed. Many refractive surgeons downplayed the physician study saying that improvements in technology had been dramatic since the study, and in their hands, outcomes were significantly better. Of course, there was no scientifically based proof to support this. “They are out of date.” “I get better results.” “They did not consider the new (whatever they wanted to emphasize) in doing their studies.” This refrain (since the days of RK) is repeated after each new study is released since most study results do not agree with what is being advertised to consumers. Unfortunately, time has proven that claims like these are to be taken lightly and these boasts of better results are overstated. FDA study results (with the exception of this first, physician sponsored study) should be taken seriously. Because as you will see shortly, physician generated data (even this so called physician sponsored PMA) does not jive with what we now know about LASIK, its outcomes and its complications.

 

“Company Sponsored” LASIK PMAs

Note the data set - the complications and incidence of these complications - provided in this, the first company sponsored FDA study of LASIK. The data set differs significantly from the physician sponsored FDA study, and gives cause for concern about what was marketed to an unsuspecting public.

 

Approval for the Bausch & Lomb Technolas ™ 217A Excimer Laser for LASIK

 

The following data were presented to the FDA for the Bausch & Lomb Technolas™ 217A Excimer Laser

System for LASIK. The date of this document is 2/28/00 and is publicly available.

This is the first company sponsored PMA for a laser used in LASIK. Therefore these are the first data presented in the more rigorously controlled company sponsor clinical trial. These data come from a rigorously controlled study with the normally high accountability.

Note that while some people had improved symptoms, others had worsening symptoms Approval, I believe, was based on the fact that the “improved” vs. “worsened” averaged out. This was good news for those whose conditions improved, but bad news for those whose condition worsened. These data suggest that symptoms LASIK patients were complaining about were real and more significant than what patients had been told since the introduction of LASIK to the US. And the incidence levels were more significant than what the informed consent’s use of the word may” suggested.

Data was presented for both 3 and 6 months for “eyes treated without astigmatism” and for “eyes treated for astigmatism.” Only one set of data is shown since “without astigmatism” is considered to be “best case” forany refractive procedure, and since six months is the longest time presented after surgery. To see all of the data, this document is available in the FDA archives. It is marked 217A-PINFO.

 

Eyes Treated Without Astigmatism at six months*

Visual Symptom Better No Change Worse

Dryness 21.6% 52.3% 26.1%

Halos 4.5% 76.1% 19.3%

Fluctuations of vision 6.8% 73.9% 19.3%

Variation of vision in dim light 14.8% 67.0% 18.2%

Light Sensitivity 14.8% 67.0% 15.9%

Blurred Vision 11.4% 73.9% 14.8%

Night Driving Vision 22.7% 63.6% 13.6%

Glare 10.2% 77.3% 12.5%

Variation of vision in bright light 6.8% 86.4% 6.8%

Redness 20.5% 73.9% 5.7%

Variation of vision in normal light 1.1% 93.2% 5.7%

Headaches 12.5% 83.0% 4.5%

Gritty feeling 18.2% 78.4% 3.4%

Tearing 9.1% 88.6% 2.3%

Burning 6.8% 90.9% 2.3%

Ghost images 1.1% 96.6% 2.3%

Double vision 3.4% 95.5% 1.1%

·  While it is not stated, some of the symptoms may occur in conjunction with other of these symptoms.

 

University of Rochester survey of FDA approved lasers

The University Of Rochester Medical Center presently has a Summary of Surgical Results Data for all FDA LASIK approved Laser Systems (The University of Rochester states all source data can be downloaded from www.fda.gov/cdrh/lasik/lasers.html ) Note the percentage who achieved “20/20 or better” by amount of required correction. This is certainly not 90% or 100%. It falls way short. Those who miss the mark will either have re-operations (enhancements) or will have to live with much less than perfect eyesight (even in high contrast environments).

They promote this to highlight the data from the newer B&L systems, which they use, and are promoting.

For systems other than the newer B&L systems, it shows uncorrected Snellen* results** as follows :

For -1.00 to –1.99 diopters of correction 46.4 to 88.2% achieved 20/20 or better**

For -2.00 to -2.99 diopters of correction 51.5 to 73.4% achieved 20/20 or better.

For -3.00 to -3.99 diopters of correction 41.7 to 67.9% achieved 20/20 or better.

For -4.00 to -4.99 diopters of correction 45.7 to 64.3% achieved 20/20 or better.

For -5.00 to -5.99 diopters of correction 40.5 to 50.0% achieved 20/20 or better.

For -6.00 to -6.99 diopters of correction 27.8 to 51.1% achieved 20/20 or better.

For -7.00 and above 32.0 to 49.1% achieved 20/20 or better.

* these data do not measure the quality of vision, eg. contrast sensitivity. The Snellen eye test was used

and only measures vision in high contrast situations.

** depending on system used.

The Medical Center’s (which appears to be marketing LASIK as StrongVision) stat sheet goes on to show that patients done on the B&L system achieve 20/20 or better 84.8 to 87.3% of the time. These data do not, to my knowledge, include re-operations, which are called enhancements. With re-ops, some of these may achieve 20/20.

 

REPORTED PATIENT PROBLEMS AND THEIR INCIDENCE

As you read the following publications, note the incidence of visual symptoms. These were not listed in the physician sponsored PMA data set (discussed previously), clearly supporting the abstentions by those who were concerned that the study was incomplete and insufficient. Unfortunately, for the millions of patients who underwent LASIK, either pre- or post- FDA approval, they made their decision on incomplete and insufficient data.

 

“Patient Satisfaction and Visual Symptoms after Laser In Situ Keratomileusis (LASIK),” Bailey, OD, MS, et

al, Ophthalmology, Volume 110, Number 7, July 2003

“97% would recommend the procedure to a friend…Halos were reported by 30%, glare by 27%, and starbursts by 25% of all subjects…The 25-30% rates of night vision symptoms here are higher than another previous study with a higher survey response rate but similar to or lower than other studies of PRK and LASIK…Increased age is associated with decreased satisfaction…Prospective LASIK patients still should be informed that LASIK has been associated with decreased satisfaction, and we specifically found that there is a 50% increased odds of dissatisfaction for every 10-year period increase of age.”

 

LASIK Has a 10% “failure” rate”, Michael Hatcher, www.optics.org, May 8, 2003

“That’s the conclusion of a study by researchers at the New Jersey Medical School. But because only most

only need one eye retreated, it means that one in five patients actually undergo a second LASIK procedure.

…This is something we have been saying for a very long time – people are not being fully appraised of their

degree of risk as it applies to their own set of eyes,” said Link (Ron Link, Executive Director of The Surgical

Eyes Foundation).”

 

 “Night Vision Disturbances After Corneal Refractive Surgery”, Fan-Paul, MD, MPH et al, Survey of

Ophthalmology, November-December, 2002

“A certain percentage of patients complain of ‘glare’ at night after undergoing a refractive surgical procedure.

When patients speak of glare they are, technically, describing a decrease in the quality of vision secondary to glare disability, decreased contrast sensitivity, and image degradations, or more succinctly, ‘night vision disturbances.’ …In most cases of corneal refractive surgery, there is a significant increase in vision disturbances immediately following the procedure. The majority of patients improve between 6 months to 1 year post-surgery…

With the exponential increase of patients having refractive surgery, the increase of patients complaining of scotopic or mesopic vision disturbances may become a major public health issue in the near future….” In the conclusion, the authors note with regards to existing testing methods, “ …lack of standardization, lack of scientific validity, hard to interpret by physician, time to administer test, hard to interpret by patient, cost, lack of correlation with symptoms, lack of familiarity with test, and superfluous…”

They go on to state, “an aging population with perplexing night vision impairments such as developing cataracts, dry eyes, or age-related macular degeneration may have worsening problems which may have a significant impact on public safety and health (in conjunction with previous refractive surgery).”

 

“Most Patients seem Happy after LASIK But They Still May be Having Vision Problems, German Study

Suggests,” John F. Henahan, www.escrs.org, October, 2002

“Although most patients who undergo myopic LASIK appear to be quite happy with the vision they achieve after surgery, they may, in fact, have measurable and sometimes significant problems with glare, halos and contrast sensitivity…However, when they were examined with a variety of objective measuring instruments, their vision was not really as good as they thought…When the Regensburg investigators used objective measurements to determine contrast sensitivity, they found that 24% had worse vision after surgery than they did before. That level of contrast sensitivity corresponds to dim -light conditions on a late autumn afternoon, and the difference was statistically significant. In addition, at 5% contrast, which simulates to night –time vision, 54% had problems…(for glare testing) 53.8% had significant problems with this test, which could be considered serious enough reduced their vision to the extent that it would interfere with their ability to drive a car…In another test (for halos), 60% were found to have some level of halos, although only 32% of the patients had subjective complaints…Therefore, even when our BCVA Snellen measurements tell us that the patient is seeing quite well, these (other) objective measurements tell us that they may be having problems especially at night…but if they come back and you question them carefully, you may find that they are no longer driving cars anymore or their vision is somewhat disturbed in the evenings.”

 

“Consumers on LASIK: Down, but Not Out,” Judith Lee, Senior Contributing Editor, Review of

Ophthalmology, Vol. No. 139:101, Issue: Oct 15 2002

“…VisionWatch Eyewear—a partnership of NOP/World Group, Jobson Publishing L.L.C. (publisher of Review of Optometry) and Greenfield Online—conducted a telephone survey of 72,000 U.S. consumers between June 2001 and June 2002. All respondents were age 18-65, and either wore some form of vision correction or had undergone refractive surgery.

Most patients surveyed who have had refractive surgery complained of nighttime glare, dry eyes, double vision and/or blurry vision. Still, most say they had recommended the procedure to others. Also, many spectacle or contact lens wearers surveyed say they are aware of refractive surgery procedures,with LASIK the most recognized. About one-third of these patients say they will likely have refractive surgery. The patients who don’t expect to have LASIK or other procedures are most worried about safety or complications. Additional concerns: cost, whether the outcome would be “worth it,” and whether the surgery will be effective as one’s vision changes.

You’re Number 1 (The Importance of the Doctor)

The survey clearly shows that eye doctors have much influence on patients. Of those who had already scheduled refractive surgery or were very inclined to have it, 35% say “my eye doctor” was the most important source of advice regarding surgery. Older patients, those with annual incomes above $60,000, and those living in the West are most likely to take their eye doctor’s advice—although patients across the board list the eye doctor as their top adviser….

 

LASIK Rules

Only about 1.5% of the total sample had already had a refractive procedure. Of this group, 87% had LASIK, with the rest divided between PRK and LTK. A surprisingly high percentage of people who had already received surgery made less than $40,000 a year. They tended to be young, live in the West or South, and had their surgery more than one year ago…

Nearly 90 % of patients had bilateral surgery, and 83% were myopic. About half were astigmatic. Six of 10 say they have suffered from haloes and glare at night and/or dry eyes. Patients age 35- 44 and those 55

 and older complained of dry eyes the most. Patients age 45-54 had the most problems with haloes and nighttime driving…

 

What Matters

Refractive-surgery candidates are most interested in improving their vision, but also would like to stop wearing glasses or contact lenses. These were the two top reasons given by patients who had already scheduled surgery or were very likely to have it.

Better vision was most important to older patients, those who made less than $40,000 and those living in the

 South. Eliminating hassle was most important to younger patients, those earning more than $60,000 and

those in the West.

When asked about other reasons they would have refractive surgery, patients mention eliminating discomfort of contact lenses or glasses, lower cost over the long term, never getting caught without glasses, and improving self image.

When deciding whether to have surgery, these highly interested patients acknowledge the risk of complications and the cost as concerns. Patients age 18-34, living in the Northeast and making more than $60,000 are most worried about complications. The respondents most worried about cost? Southerners who are 35-44 and make less than $40,000 a year…”

 

“Laser In Situ Keratomileusis (LASIK) for Myopia and Astigmatism: Safety and Efficacy – A Report by the

American Academy of Ophthalmology”, Alan Sugar, MD, MS, Christopher J. Rapuano, MD, et al,

Ophthalmology, Volume 109, Number 1, January 2002.

“Conclusions: Serious adverse complications leading to significant permanent visual loss such as infections and corneal ectasia probably occur rarely in LASIK procedures; however, side effects such as dry eyes, nighttime starbursts, and reduced contrast sensitivity occur relatively frequently. Some of the most satisfied eye care patients are LASIK patients, and the goal is to continue to increase the percent of patients who are happy with this surgery.”

 

“LASIK Patients at Risk for Long-Term Eye Irritation, Study Says,” American Academy of Ophthalmology,

Press Release, July 2, 2001

“Based on a July, 2003 study published in Ophthalmology. Authors say that LASIK patients with reduced ocular sensitivity due to long term wear may take years to regain normal ocular surface sensitivity, if ever…fluctuating vision reported by many in study improved after blinking or use of preservative-free

 artificial tears.”

 

DISCERNING THE TRUTH ABOUT “THE NEXT BIG THING”

The patient/consumer must be diligent with the introduction of “improved’” and/or “new” refractive methodologies and technologies. The “refractive surgery medical-industrial complex” is looking for “The Next Big Thing.” The refractive surgery market has contracted since its peak in 2000. Today, lasers are underused. Competition for the patient is fierce. Surgeons, national chains, and manufacturers are seeking a real or imagined competitive edge. With high fixed costs in laser based refractive surgery, financial problems lurk for those who fail to achieve adequate patient volume. The environment requires caution and discernment for those interested in “getting rid of their glasses and contact lenses.”

 History is a guide to how emerging procedure improvements and new approaches will be marketed to gain a competitive edge. Initially, PRK surgeons advertised that PRK was superior to RK since the procedure was not surgeon skill based but rather technology based. PRK brought to the procedure “Star Wars” technology, and micron accuracy. It was not too long after PRK was introduced that LASIK was introduced and LASIK competed against PRK on the basis of day one results - pain free and great vision. As competition grew, surgeons then competed on experience as LASIK was touted as skill based. Advertising moved to highlighting how many procedures a surgeon had done.

The low price National Chains entered the market in 2001 and price became the differentiator. These Chains believed they could create scale, leveraging the marketing/advertising expenses, and could provide LASIK, without compromising the quality of the procedure, at a much lower cost. The marketing costs per patient in those days were close to $400 per eye.

Those surgeons who were not part of a chain were at a competitive disadvantage, including most of the Academics, and refractive elite. To retaliate, this group began to equate quality with price through advertising, and as spokespeople for local news stories focused on LASIK catastrophes. The overall strategy was to create fear in the mind of the consumer towards a lower priced procedure and national low priced chains.

The latter tactic is interesting. There is no data to support any claim that price is related to the quality of the outcome. In fact, the data presented thus far shows that the procedure has certain flaws, which are not surgeon or price dependent. Patient’s should be concerned more with the procedure than its price. As price and quality became an issue, another group of surgeons, to differentiate themselves, advertised that they were the go-to surgeons for repairing LASIK complications. The message was “we are the best since we do the really tough cases.” Many of these were surgeons who promoted LASIK in its introduction as safe and complication free. Now, it has complications but if you come to me, I know how to deal with them. One reporter I know was confused as she talked to doctors She said that these doctors assured her only one year before that LASIK was problem free. Why were they now pushing their importance as the “go to docs” for LASIK problems. She wondered what problems were being fixed if none existed!

 

 

 

 

“Off the Cuff: LASIK and Contact Lenses – Can’t We All Get Along?” Arthur B. Epstein, OD, FAAO, Chief

Medical Editor, Optometric Physician, June 16, 2003 “Over the past month I’ve seen signs of a ramping up of anti-contact lens activity by some ophthalmologists involved in refractive surgery. It would seem that the success of silicone hydrogel contact lenses is makin LASIK surgeons a bit nervous. After all, continuous wear contact lenses do make an attractive alternative to irreversible refractive surgery for many patients.

Some in the contact lens community believe that the anti-extended wear onslaught of the past decade had politico-economic motivation. Whether this is true will always remain conjecture. However this time around, with some optometric offices filled with LASIK disasters seeking rehabilitation and relief, the shoe can easily be on the other foot…”

 

Wavefront Guided LASIK

As you read about what is in development pipeline for commercialization, keep in mind the economics of refractive surgery, the economic investment and burden for a surgeon or a center, and the absolute need to increase throughput to remain solvent. Surgeons will adopt new procedures and/or modifications to old procedures, whether they are ready for prime time or not, due to competitive pressure.

Wavefront is a good example. Surgeons, even if they do not believe in it, will adopt it and push it so they will not be left behind. Despite wavefront’s adding little if any value, surgeons and national chains will try to use it to differentiate themselves from others (particularly those who cannot afford the change) and to raise prices. The hype and misinformation have already begun as some of those who have adopted it are already touting it as “safer” than the original LASIK. Since there is no FDA clinical data to support the claim of “safer”, this is a bogus and illegal claim. Like the original LASIK, it involves a flap, and the flap is still the major source of short term and long term “safety” problems.

 

 “Challenges to Wavefront Correction, Introduction,” George Waring, III, MD, FACS, FRCOphth, Editor-in-

Chief, Journal of Refractive Surgery, Volume 18, November/December 2002.

“These, along with dozens of articles in other journals and presentations, can leave the impression that wavefront analysis will lead us to the holy grail of super vision for our patients, most seeing 20/10 without correction. Such a simplistic cartoonish view is, of course, unrealistic and inaccurate.”

 

“Wavefront technology: A New Advance That Fails to Answer Old Questions on Corneal vs. Refractive

Astigmatism Correction,” Noel A. Alpins, FRACO, FRCOphth, FACS, Journal of Refractive Surgery, Volume

18, November/December 2002.

Page 738. “A second issue is that the correction of all ocular aberrations at the corneal surface pays no regard to the effects of corneal irregularities that will be produced by this uneven mode of treatment. Refractive surgeons have long known that corneal regularity (orthogonal and symmetrical astigmatism) is the foundation of a super visual outcome. Corneal irregularity can only increase if all corrections for internal optical errors are surgically sculpted onto the corneal surface without considering any pre-existing corneal topographical irregularities.

Technical challenges also impair our ability to accurately align the ablative patterns to make the focal changes to correct underlying optical aberrations. It is difficult to permanently change regional corneal shape in this uneven manner, especially when the treatment can be neutralized by epithelial healing. Any change in the crystalline lens will also complicate the long-term usefulness of wavefront driven changes.”

 

“Thirty-four Challenges to Meet Before Excimer Laser Technology Can Achieve Super Vision,” Isaac

Lipshitz, MD, Journal of Refractive Surgery, Volume 18 November/December 2002

“In correcting higher order aberrations, minor changes count. Corneal surface changes must reach an accuracy of one micron; only one or two laser shots delivered in a slightly wrong position or incorrect timin will interfere with the desired result…These 34 challenges are divided into four main groups:

 

·  Ocular Challenges

1. Changes in (the eyes) wavefront with age…new aberrations will appear subsequently withage…

2. Changes of wavefront during accommodation (dynamic vision factor). (Accomodation is your eyes ability to focus far and refocus near) Even if we achieve super vision for distance vision, when looking at near, newly higher order aberrations may occur.

3. Effect of pupil size on higher order aberrations. Change of pupil size – in light, dark, accommodation, convergence – dramatically affects vision…

4. Biomechanical differences among corneas before surgery. Corneas differ considerably in their biomechanical properties…depends on age, corneal thickness, hydration, and collagen properties...

5. LASIK flap biomechanics. Once a LASIK flap is created, the biomechanical properties of the cornea change dramatically depending on the depth of the incision, diameter of the flap, location of the hinge, and uniformity of the flap…even it the flap is returned to its place without ablation – there is a change in the wavefront measurement…

6. Changes in tear film. Tear film properties in different eyes occur because of common pathologies such as dry eye and blepharitis…

7. Changes in corneal thickness after laser surgery…affects tear film, the biomechanical properties of the cornea, the healing process, and mechanical strength of the cornea…

8. Changes in wavefront during cycloplegia…

9. Variation of ablation rate in different depths of the cornea…

10. Variation in corneal thickness in different meridians. Usually the cornea is thinnest in the inferior or inferotemporal area, probably because these areas are dryer (they get less tears)…

 

·  Uncontrolled Optical Changes During the Healing Process

11. Corneal epithelium wound healing…

12. Corneal collagen wound healing…

13. Effect of corneal biomechanics after surgery…

 

·  Technological Limitations of Surgical Equipment

14. Eye positioning during preoperative measurement and laser treatment.

15. Accuracy of laser ablation…the exact amount of corneal tissue removed with each laser pulse changes continuously…

16. Microkeratome accuracy and profile. At a specific setting, microkeratomes cut flaps of varying thickness – varying among manufacturers, among instruments, among eyes, and at different regions in a single flap…

17. Tracking the location of the laser beam…

18. Decentration…

19. Accuracy of the wavefront sensors…

20. Computer programs for the laser…the current capability of computer programs to integrate this enormous about of data and to give to each piece of data the exact value required by the laser is questionable…

21. Accuracy of the laser. Two instruments from the same company may work differently…

22. Consistency of one laser. The laser pulse energy changes all the time, so the instrument calculates and uses an average energy…

23. Chromatic aberrations are not detected by aberrometers…

24. Location and shape of wavefront measurements…

25. Objective aberrometers measure only the optics of the eye…This influence on surgical outcome is now known; perfect optics do not assure perfect vision…

 

·  Uncontrollable Surgeon Variables

26. Dryness of the ablation surface…

27. Environmental issues during surgery…The temperature changes constantly due to the heat generated by photoablation…

28. Retinal problems of aberration-free optics. We still don’t know if directing all the rays of light on the fovea (area of least confusion) – which is what we are going to do if we want to create super vision – will cause thermal or toxic damage to the retina. Maybe that’s why there are optical aberrations in our eyes…

29. Possible worsening of visual performance with inaccurate surgery…

30. Effect of enhancement procedures on the wavefront. Currently, we have an enhancement rate of 5% to 25%, which is done only for lower order aberrations. If we expect to correct many higher order aberrations, a considerably higher number of re-operations may be needed. But, each enhancement procedure has its own effect on the total higher order aberrations because of lifting and repositioning of the flap.

31. Positioning the flap after ablation...

32. Flap edema after ablation…

33. Curvature of the flap and bed do not fit perfectly after ablation…

34. Irreversible procedure…the original condition of the eye cannot be restored. …Refractive surgery – especially LASIK – must overcome many challenges to reach this goal (super vision).”

 

“Biomechanics of the Cornea and Wavefront-guided Laser Refractive Surgery,” Cynthia Roberts, PhD,

Journal of Refractive Surgery, Volume 18, September/October 2002

Page S589+. Although it has been demonstrated that image quality after customized procedures is improved over that of standard procedures (based on higher order aberrations), there are still significant aberrations induced after a wavefront-guided procedure that are neither expected or predicted… Figure 1…illustrates a preoperative cornea where the inter-lamellar spacing is defined by parameters including geometry of the system, the tension carried in the lamellae, the internal fluid pressure, the interlamellar cross-linking, and the load imposed by the intra-ocular pressure…Also illustrated is a postoperative cornea…The remaining peripheral lamellar segments are relaxed to the maximum depth of the cut, and cannot bear the same tension as in the preoperative state…(For LASIK) there are only certain shapes the cornea will accept, and the “ideal” shape that produces the “ideal” correction is likely not among them. Any procedure that circumferentially, or near circumferentially, severs corneal lamellae will produce a biomechanical response that will alter corneal shape in a manner that cannot be predicted with wavefront analysis alone.

 

 “Some foresee limitations in wavefront technology,” Ocular Surgery News, August 1, 2002

Michael Goggin, MD, of Adelaide University said, “Aberrations increase with age. What we do now may lose its effect in ten years. He “wondered whether there would be problems matching IOLs to customized corneas in patients who develop cataracts after wave-front ablations.”

 

“Effects of Accommodation and Flap Biomechanics May Complicate Quest for Super-Vision,”” EuroTimes,

March 2001,

Ionnis Pallikaris, MD, pointed out in his presentation to the Winter Refractive Surgery Meeting in Cannes, that “vision in the human eye is not a static, but dynamic process, and the process of accommodation (adjusting for near and far vision) in a day-to-day basis and as an individual ages can influence the wave front aberration profile of the eye and consequently confound attempts to achieve “super-vision” with LASIK or other refractive procedures.

 

“Reflections on Refractive Surgery”, Olivia Serdarevic, MD, EuroTimes, March 2001.

Reporting on the Winter ESCRS meeting in Cannes….”There was also a consensus about the frustration with our current incomplete knowledge of and ability to modify many optical, biomechanical and biomolecular effects of refractive surgery…The speakers agreed that the endpoints of 20/10 or better visual acuity and aberration-free vision, which have been promoted not only to ophthalmologists but also to patients, represent very simplistic, naïve and erroneous assessments of our visual function and needs…Wavefront aberrations of the optical system are dynamic.. How can successful integration of wavefront analysis and laser ablation occur before complete standardization of measurement in normal eyes during the performance of different visual tasks over time? …How can we use wavefront information for computer programming of laser ablation in normal eyes before we adequately analyze wavefront aberrations induced by LASIK flaps and existing laser ablation methods and correlate these aberrations with corneal shape, biomechanics and wound healing?…Many…attending the meeting were getting tired and worried about exaggerated and erroneous “super vision correction” claims.”

 

IntraLASIK™ (Intralase™ LASIK)

IntraLASIK is an all laser procedure that provides, most importantly, a laser alternative to making the flap. It claims to eliminate much of the variation caused by the mechanical microkeratome in flap creation. Some surgeons have purchased this to differentiate themselves from those that use a mechanical device. Some of the surgeons promoting IntraLASIK are promoting it as “safer” than LASIK. There have also been several recent stories in the mainstream news talking about it being safer than traditional LASIK with a mechanical microkeratome. Be aware that there is no FDA data to support this claim and it is illegal to for anyone to

make this claim.

While there are trade-offs to using IntraLASIK over the microkeratome, some of which are positive, don’t forget that a flap, regardless, of how it is made, is a flap. The creation of the flap is one of the fundamental flaws of LASIK as it destroys the homogeneity of the cornea, and weakens it. Only time will tell if LASIK and/or IntraLASIK leads to a loss of effect (as the cornea becomes steeper, or bulges out) or in worst case, leads to ectasia.

 

LASEK (an emerging off-label procedure)

“LASEK learning curve steep, despite experience, surgeons say,” Ocular Surgery News, July, 2003

“Mastering laser epithelial keratomileusis is challenging, and creating the epithelial flap is more difficult than the literature suggests…The study should alert surgeons that ‘LASEK is not a reproducibly easy procedure at its start,’ the authors said. ‘Moreover, additional studies should be conducted with longer follow-up to guarantee that corneal haze (incidence of 65%) is not a long-term problem ….”

 

“Surface ablation gets high marks at LASEK meeting/ highlights of the international LASEK congress

included discussion on corneal haze and night vision,” Nicole Nader, Ocular Surgery News, July 1, 2003

“Laser epithelial keratomileusis is a promising technique, but the pitfalls of older surface ablation techniques (PRK), such as corneal haze, are still an issue….Significant corneal haze ‘may’ occur after LASEK…At 6 months postop, grade 0.5 haze was present in 58% of the patients, grade 1 in 25% and grade 2 in 8% of patients . (‘may’ in this context means an incidence of 91%!!!)…’ninety percent of my patients were testing positive for starburst phenomenon,’ he (Bruce Larson, MD) said….‘Results showed that LASIK produced significantly more starbursts than LASEK’…

LASIK pitfalls discussed….LASIK has the potential for complications that are not seen in other refractive procedures, including increased coma, keratectasia (ectasia) and surgeon-induced irregular flaps, according to a number of presenters…several surgeons described complications seen in LASIK but not in surface ablation procedures such as LASEK.”

 

Lens-based refractive surgery – Intraocular lense s (phakic IOLs)

Refractive (phakic) IOLs are on the horizon. These include products like the ICL and the Artisan lens. A these products are introduced, their proponents will layout the problems of laser-based procedures (LASIK, wavefront, etc.) as never before. Pay close attention to FDA data on inclusion data (who can benefit), on adverse events, complications, and visual problems. These procedures are the most invasive of any known procedure. The surgeon must go into areas of the eye that are very small and/or dynamic presenting serious new risks. As an analogy, this is comparable invasive surgery for the eye as open-heart surgery is for the heart.

These procedures may be marketed as reversible. Understand completely what that really means. To extract and replace a lens is no simple procedure and can lead to other problems. If someone markets this as reversible, ask to see the FDA outcomes/complication (post removal) data that proves reversibility. Do not accept “personal study” results.

 

“Some refractive procedures carry higher retinal risks, study finds,” Ocular Surgery News, September 29,

2003, Re: Study published in The Journal of Refractive Surgery, September-October, 2003

“Certain refractive procedures for myopia pose a greater risk of postoperative retinal problems than other refractive procedures, a large cohort study suggests. Phakic IOLs created the highest risk for retinal detachment in the study, followed by LASIK and then photorefractive keratectomy (PRK)…

Retinal detachment occurred at a mean of 53.6 months after PRK in nine eyes (0.15%), 24.6 months after LASIK in 11 eyes (0.36%) and 20.5 months after phakic IOL implantation in 12 eyes (4%). Choroidal neovascularization occurred in 10 eyes that had undergone LASIK (0.33%), in seven with a phakic IOL (2.38%) and in one that underwent PRK (0.01%).”

 

Multifocal phakic IOL an option for hyperopia,” Ocular Surgery News Supersite, September 15, 2003

MUNICH, Germany — A multifocal phakic IOL can be an efficient, potentially reversible refractive surgical option for patients with hyperopia, according to a presentation here. Georges Baikoff, MD, spoke on the use of a bifocal anterior chamber phakic IOLs at the European Societ of Cataract and Refractive Surgeons meeting. He shared the results of his personal study using the lens during a symposium on hyperopia…

…He said there was some incidence of glare and halos, but these were accepted by patients. There was also an acceptable loss of contrast sensitivity compared to preop, he said. “It is mandatory to tell patients that this is a compromise between excellent vision with spectacles and good vision with the IOL,” Dr. Baikoff said.

He noted that in using anterior chamber phakic IOLs, accurate biometry is necessary to ensure that patients have sufficient anterior chamber depths. Shallow anterior chambers are prone to angle closure, and there is risk of endothelial cell loss, he said.

 

“Lens-based refractive surgery shifting focus from the cornea to the lens,” Nicole Nader, Ocular Surgery

News, July 1, 2003

“…on the other hand, lens -based surgery also carries considerable risks: the increased risk of intraocular procedures…, the possibility of complications associated with IOLs, the heightened risk of retinal detachment, and with phakic IOLs, the possibility of inducing secondary glaucoma or cataract…”

 

The ICL™ (the Implantable Contact Lens)

The ICL has been commercially available outside the United States for a number of years and is making its

way through the FDA approval process in the US. The ICL is a very small micro lens that is placed in the eye (very invasive surgery) in a very narrow space between the iris and the crystalline lens. It has had a history of problems outside the US with complications that include cataracts and glaucoma. The company that manufactures the lens claims that these problems have been solved. One interesting historical note is that those surgeons promoting the ICL changed the terminology relating to pre-cataract conditions to a new term, ”opacities”. “Opacities” is a benign and misleading term compared to pre-cataract or cataract. From an anatomical point of view, the ICL is being placed in one of the most dynamic and hostile environments of the eye. The iris and the crystalline lens (unless it has been replaced with an intraocular lens) are constantly moving. The iris opens and closes (like a camera lens) to let in the appropriate light rays, while the crystalline lens expands and contracts as it provides zooming power (accommodation) for reading and distant sight. If the ICL touches the iris, pigmentation of the iris, which provides your eye color, will be dispersed. This can lead to glaucoma, which, in turn, can lead to blindness. In addition, if the ICL touches the crystalline lens, the crystalline lens will develop an opacity, which historically has been considered a condition that could lead to a cataract. If it becomes a cataract, the natural lens must be removed and replaced by an intraocular lens. With the IOL, the eye loses its focusing capability. For those who do not need reading glasses, this may become a serious inconvenience. For those who have lost the ability to focus (usually over 50 years of age), this may not be a problem.

The ICL must be place exactly right to avoid complications. When you understand the maneuver that must be made to insert this lens, you will understand that this procedure requires great skill. If a claim,, or any semblance of a claim, of reversibility is made by a doctor, check the FDA approval. It is highly doubtful that the FDA will grant this marketing claim. Removing the ICL can result in touching either or both the iris (pigment dispersion/glaucoma) and the crystalline lens (opacity formation/cataracts). There is little if any margin for avoiding these problems in a removal.

The recent press releases and publications on this procedure need to be reviewed with great care. Hype and misleading statements have begun. For the publications, find out who the authors are and what relationship they have to the company.

One recent study argued that the complications like retinal detachments, glaucoma, and cataract were no different for the general population as they were for ICL patients. This was not a scientific head to head comparative study. The authors, some of whom are paid consultants for the manufacturer, implied that there is no need for concern when these problems occur after an ICL procedure. The study is bogus and the conclusion is not reasonable. For a study to reach this conclusion, it would require a scientific based longitudinal (five years or more) study including a control group that did not have the ICL. Studies and conclusions like this will be developed and promoted by ICL enthusiasts to convince an unsuspecting public of the procedure’s safety and efficacy.

The FDA panel has approved the ICL by a 8-3 vote for commercialization. Note the success rate in the Reuters news story on the approval, and information that the company provided preceding the approval. Note the differences.

 

UPDATE - US panel urges approval for Staar implanted lens, Lisa Richwine, Reuters, October 3, 2003

“GAITHERSBURG, Md., Oct 3 (Reuters) - A U.S. advisory panel on Friday voted 8-3 to urge approval for Staar Surgical Co.'s (NasdaqNM:STAA - News) implantable lens to correct nearsightedness, a possible alternative to laser eye surgery. If the Food and Drug Administration (News - Websites ) agrees with the panel, which it usually does, the product would be the first implantable lens sold for people whose natural lenses are intact. Implanted lenses on the market now are used to replace lenses following cataract surgery. Staar's product is a refractive lens that physicians inject through a small incision and place behind the iris. The company aims to market the procedure for people age 21 to 45 with moderate to severe nearsightedness, or myopia. In a trial evaluating more than 500 eyes that had the lens implanted 84 percent had vision of 20/40 or better one week after the procedure. Three years later, 81 percent had that level of vision, the company said. Some patients experienced a gradual loss of cells in the cornea, an issue of concern to the panel. Some loss is normal, but panelists said they could not tell from the current research whether the loss would continue over time and damage the cornea. The company argued the cell loss stabilized in three to four years, but the panel said the research did not prove that was the case. "We don't know what's going to happen in 10, 20, 30 years," said Dr. Marian Macsai-Kaplan, a panel member and chief of ophthalmology at Evanston Northwestern Healthcare in Illinois. The panel, by a 6-5 vote, urged the FDA to require Staar to monitor the cell loss annually for five years in certain patients who took part in the clinical trial. Some who dissented felt the long-term data should be collected before the device is allowed on the market. The Staar lens would offer an alternative to the popular Lasik surgery, in which physicians use a laser to reshape the cornea and correct vision. Staar calls its device an implantable contact lens. Panel member Timothy McMahon, professor of ophthalmology at the University of Illinois at Chicago College of Medicine, said that description was a "euphemism" that could mislead patients and should not be allowed…”

 

 

“U.S. Food and Drug Administration clinical trial of the Implantable Contact Lens for moderate to high

myopia,” Staar Surgical, Ophthalmology, August, 2003

“Twelve months postoperatively, 60.1% of the patients had visual acuity of 20/20 or better, and 92.5% had an uncorrected visual acuity of 20/40 or better (ed note: 20/40 is required to drive a car without corrective lenses, therefore, 7.5% of ICL patients will not pass the driver’s license exam)…presumably surgicallyinduced anterior sub-capsular opacities (ed note: cataracts) were seen in 11 cases (2.1% of the group)…Patient satisfaction was reported by 92.4% of subjects on the subjective questionnaire.” In its investor related quarterly conference calls., the company has been projecting significant acceptance of the ICL procedure. Note that with an induced cataract incidence of 2.1%, 21,000 out of every million Americans having this procedure will develop cataracts. This will mean further irreversible surgery to remove what was once a healthy crystalline lens. It will be interesting to see how the company and surgeons market this procedure and what role the FDA will play in insuring that communications are not misleading.

 

“99.4% ICL Patient Satisfaction Level Linked to Superior Image Quality,” Press Release by Staar Surgical,

July 24, 2003

The above press release (available on the Staar website) is a company press release reporting on a study conducted by a group of doctors who compared their LASIK results to their ICL results. These doctors are not unrelated parties to Staar Surgical, the manufacturer. These doctors then took their results and created a mathematical model to simulate the visual image of what a patient saw after each surgery. “The comparison clearly demonstrates a sharper and clearer image in ICL patients… the study concluded that the

ICL was safer and more effective than LASIK….and why the ICL will become a prominent choice for vision correction.”

This press release is another example of the care patients must take to discern the facts. First, the referenced study group was very small. The study was not a FDA regulated study. And the claims of “safer and more effective” are not only misleading, but are also illegal. Secondly, patient satisfaction percentages are an exaggeration when compared to the FDA study (which precedes this section). Finally, the creation of a mathematical model requires numerous assumptions. Those who are in experts in mathematical modeling

know that the models cannot provide specific, accurate information but only trends.

 

The Artisan™ Lens

The Artisan lens is a Dutch (Oftech, Groningen, Holland) developed lens that has been in use outside the US for more than 15 years. The lens is placed in the eye between the cornea and the iris contrasting with the ICL which is placed between the crystalline lens and iris. The company founder, Jan Worst, MD., is one of pioneers in intraocular surgery. Dr. Worst is principled and well-respected. He and his company have historically not oversold any of their products. Unlike other procedures, excepting RK,  the outcomes and

complications of the Artisan Lens have been fully characterized over 15+ years. The Artisan is in US FDA clinical trials today.

Since the Artisan may prove to be a formidable competitor with its well-defined outcomes, those vested in

other less characterized procedures have already started to put negative spin on the Artisan. One competitive company, in its press releases, calls the Artisan approach archaic and first generation surgery,

claiming that surgeons will want something more modern. This company also claims to have the “third generation” product, which is much easier for a surgeon to use. This company has steered clear of the longitudinal (over time) outcome/complication comparison and is focusing investors, surgeons, and interested patients on ease of use. Discerning patients would be well advised to focus on the Artisan’s years proven outcomes, and not something that is “easier to use.” While “ease of use” may save money in the short term for the surgeon, it does little for the quality of life of the patient over a lifetime.

 

Radio-frequency Procedures for hyperopia

An emerging group of procedures for hyperopia includes using heat to heat up the collagen in the cornea,causing it to shrink, and thereby causing the cornea to become steeper. Radio-frequency generated heat,and holmium laser heat are in this group of procedures. Heating the collagen is a potential solution for hyperopia since the cornea is too flat and needs to be steepened. The good news about these procedures is that they are, to a great extent, reversible. The collagen in the cornea tries to return to its original thickness, and the cornea to its original shape. The bad news is that outcomes are variable, outcomes may be short-lived, and the variability of the outcome will persist as the cornea tries to reach equilibrium.

 

SUMMARY

·  Historically, the “refractive surgery medical-industrial” complex has used selective information to move patients to a refractive procedure. Patients must perform adequate diligence on their own to insure that they fully understand the risks and benefits of any procedure. Surgical Eyes, www.surgicaleyes.org, is a very valuable resource for those seeking balance.

·  An illusion of safety has been created around refractive surgery through selective marketing. Purveyors of the illusion have a vested interest in keeping it going. Interests can range from financial greed, fear of exposure for doing something that can cause harm (thou shall not do harm), to the fear of being sued. The enormous complexities of human behavior that are motivated by greed, a fear of exposure, and financial loss are at work here. Fear leads to oppression and tension. The natural inclination is to hide from failure and to give the impression of perfection. If exposed, public rejection and lawsuits will follow. LASIK surgeons have made their Faustian bargain, and at some level they know it.

·  LASIK has basic flaws that are independent of a doctor’s skill level (and what you are being charged). These include quality of vision degradation due to loss of asphericity, dry eye due to several anatomical factors, a weakened cornea, due to the creation of a flap. The weakened cornea may lead to the loss of correction effect and ectasia. Ectasia may be the Achilles heel for LASIK as the cornea never regains its initial strength and homogeneity after the flap is cut. Cells may seal the flap preventing infection but the underlying structure never heals and remains in a weakened state. The cornea, with time, may bulge forward due to the internal pressure inside the eye causing a loss of effect and/or irregular bulging.

·  Dry eye is a troublesome problem. A great deal of money is invested annually in the search for a cure and effective treatment by private industry and the US government (NIH). It is a paradox that while money (taxpayers dollars) is being allocated to solve this problem, refractive procedures now add to the prevalence of this problem.

·  “Real” complication rates of a procedure are openly discussed, not when the procedure is popular, but rather when providers are pushing newer, “improved” procedures and want to obsolete the older procedure.

·  The anatomy of the eye is dynamic, changing with age. Optical aberrations are dynamic as well. Irreversible correction of vision (particularly with tissue removal), whether with LASIK or wavefront guided LASIK, only corrects vision at one point in time. This becomes problematic with age when new aberrations are introduced and/or with the onset of certain eye diseases. Upgrades are not anoption!

·  Reaching 20/20 does not mean a high quality vision outcome. You may still be seeing 20/20 but you may have degraded vision, particularly in low light environments and at night. Nevertheless, with a 20/20 outcome, the “refractive surgery medical-industrial” will consider and promote you as a refractive success.

·  The use of adverse events, complications, and visual symptoms are medical terms unique to ophthalmology and are easily misunderstood by consumers when asking the incidence of problems. Patients should be informed of the definitions, should consider visual symptoms a complication, and should ask physician/providers for a full accounting, incidence, and severity of all visual symptoms.

·  Due to the significant upfront investment and operating overhead required to operate a refractive surgery center/practice, throughput (volume of procedures) is critical to financial survival. Investments made include the equipment, a highly trained staff, marketing and advertising, and referral payments to other physicians. High investment and high fixed costs have been key drivers in the marketing of refractive procedures.

·  There is no science-based study showing that paying a price of $499 versus $1500 will provide you with a better outcome or fewer complications. Those who charge more prefer that patients believe price makes a difference, but only so they can generate more patient traffic at a higher prices. But, the bottom line is a LASIK is a LASIK, cutting a flap is cutting a flap.

·  Vision is critical to athletic performance. Professional athletes like Jennifer Capriati (tennis), Troy Aikman (football), Tommy Armour III (golf) and Scott Hoch (golf) have had LASIK, and have had their vision and their performance compromised. For example, Armour lost all depth perception after LASIK, nearly lost his PGA exemption, and now wears specialty hard contact lenses to compete. A quick search on www.google.com will yield information about the other athletes. One very special athlete to watch closely is Tiger Woods. Ophthalmology hallway conversation highlights that Tiger had an 11.0 diopter (nearsighted) correction with LASIK, and up to three enhancements. He had problems immediately after the procedure (as reported by him on HBO), appears to have some difficulty on overcast days (lowlight), and is now struggling two years after his procedure. Due to the size of correction (the depth of flap required), Woods is at “high risk” for an unstable cornea and ectasia long term.

·  Do your homework before you proceed with any irreversible refractive surgery procedure. Investigate all potential conflicts of interests. Make sure that all of the healthcare providers you are

dealing with have your well-being foremost in their hearts and minds. You only have one pair of eyes!!

 

·  Appendix A contains a recent introspective editorial by WilIiam Maloney, MD. suggesting that the surgical profession must move forward cautiously in adopting new refractive techniques so as not to repeat the mistakes of the recent past. While it is much less detailed and shifts much of the blame to “sales people”, it is a good companion piece to “The Promise of Refractive Surgery: A Promise Not Kept.” The failure of keeping the promise is not a “salesman” problem but rather an industry problem. There has been and continues to be an unconscious conspiracy within the “refractive surgery industrial-medical complex” placing the patient’s interests secondary to vested interests.

 

APPENDIX A

“Apply lessons of the LASIK experience to refractive lens exchange : Surgeons should take it slow when it comes to this new lens-based refractive technique,” William F. Maloney, MD, OCULAR SURGERY NEWS September15,2003

This month we are going to take a short detour from our discussion of specific techniques used in refractive lens exchange. I would like to bring out an issue that needs to be addressed as this procedure takes center stage. Let us call it the bandwagon effect or “the next new thing” problem. After rereading each of my past columns on refractive lens exchange, I noted a clear sense of concern in comments such as these:

“I am one who feels strongly that the transition from cataract surgery to refractive lens exchange ought not be taken for granted.”

“The techniques are proven and ready. As surgeons are we ready?”

“Performing cataract surgery without the cataract suddenly shifts the outcome equation to results that consistently must be very near perfect. In order to cross the 20/20 threshold responsibly, each surgeon must ask, ‘Have I prepared enough to be sure that I can deliver results at this level on a consistent basis?’”

What concern lies beneath statements like these? Why am I suddenly the sober cautionary voice of restraint? After all, my revolutionary credentials are intact. I was on the barricades teaching phaco and IOL-related innovations throughout the ’80s and ’90s. I have long been on record saying that refractive lens exchange is a procedure whose time has come, predicting that it will play a central role in the future of refractive surgery. Now that the tipping point has arrived and more and more surgeons are reaching the same realization, why am I suddenly feeling uneasy?

I think the answer is that I am concerned for what might happen to refractive lens exchange if it becomes the next new thing. I see increasing signs of hyperbole in such projections as the entire baby boom generation lining up to have their presbyopia corrected at $3,000 per eye just as soon as one of the accommodating IOLs becomes available. If experience with LASIK has taught us anything, it should be that hype is not in the long-term interest of our profession.

 

Jumping on the bandwagon

Refractive lens exchange, increasingly seen as the fastest growing refractive surgery technique, is currently a whitehot topic. After steadily working with this approach in my cataract patients since 1986, the suddenness with which this procedure has become a front-page feature has begun to make me uneasy.

It reminds me of the first years of PRK and then LASIK, which was almost immediately proclaimed the treatment of choice for all refractive error from +8 D to –20 D. It never happened, of course. As the limitations of LASIK have become increasingly difficult to ignore, the recommended treatment range shrunk steadily to what is now a range somewhere around plano to –8 D. This is close to LASIK’s starting point when it was introduced on the heels of radialkeratotomy.

No one would argue that LASIK is not a major advance over RK. Significant progress was made, but in getting there, we got it backward. Instead of a measured, step-wise advance from —7 D (where RK had brought us), we joined in a collective leap of faith to –20 D and have spent a good part of the past decade backpedaling. How did we manage to get this one so wrong? I think it happened in part because LASIK was arguably our first bandwagon phenomenon — jump on now or risk being left behind. The seeds of the LASIK letdown were sewn from the start when LASIK was snagged by the next new thing phenomenon. The rest is history — a history that we mus t not repeat and with lessons that we must be sure to learn.

 

Too far, too fast

This bandwagon effect was enhanced by several factors. At least part of its origin can be found in the phaco and IOL revolution. We are all aware that this first technology-driven revolution led to a golden age of unprecedented progress in cataract and refractive surgery. Ophthalmology can be justifiably proud of the truly remarkable accomplishment that is cataract surgery today.

Revolution, however, is almost always a two-edged sword, and history repeatedly tells us that revolutions can end up devouring themselves if they are unchecked and allowed to carry too far. This phenomenon — call it overshoot — typically occurs because of the inevitable transfer of power at the center of every successful revolution. The principal players in the old power structure either capitulate and join the revolt, or they are marginalized. Either way, the old guard’s conservative, usually self-interested voice of restraint and moderation is silenced. Like a coiled spring suddenly released, the momentum of unchecked forces for change can easily carry too far, jeopardizing the original gains of the revolution.

This historical template aligns perfectly with the phaco revolution. After a struggle (Ridley, Kelman and many early pioneers have all described this), the old guard of traditional ophthalmology finally capitulated and joined the ranks of phaco and IOL surgeons. They had seen their influence eclipsed. They had lost the spotlight to a ragtag army of private practitioners who took control of the podium, describing small-incision cataract surgery performed in unprecedented volumes with remarkable efficiency and vastly superior results.

The old guard learned all too well the futility of resisting the power of an idea whose time had come. It is hardly surprising that they were determined not to be on the wrong side of the next revolutionary concept when it first came into view. The stage was set with the bandwagon at the ready. Ophthalmology (surgeons and industry) scanned the technology-laden horizon for the next new thing. It was PRK and then LASIK, and the scramble to get on board erupted with a vengeance.

 

Progress with precautions

At the core of the next new thing problem is that it does not encourage the slow, steady and thoroughly verified progress that patients assume has already occurred by the time they encounter a new technique. The threshold for accepting and utilizing new technology tends to fall beneath the level required by the more sober long-term demands of our profession. In this overheated environment with a sense of urgency not to miss the boat, our collective point of persuasion can get reset too low, blurring the vital distinction between science and salesmanship.

We practitioners can too easily forget the one thing we must never forget: The industry representatives are the salesmen, and we are the scientists. Hype is often a completely appropriate tool for the sales force with specific short-term financial goals or a strategy for gaining market share. For us physicians, it can only be counterproductive. There is a line at which the interests of the industry and those of our profession, which are usually well aligned, can act at cross-purposes. One of our primary responsibilities as medical professionals is to carefully monitor that line.

 

Lessons from haiku

The oath we took separates us and defines us as the most esteemed of professions. We have much to lose when we fail to fully honor that oath. This is a wonderful ideal that unfortunately may be at risk of becoming a cliché. Let me conclude with an appeal to resharpen our focus on that sentiment, for in my opinion it lies at the heart of this issue.  There are two Japanese art forms that I have particularly enjoyed since first visiting Japan to teach phaco with Dick Kratz and Dave Dillman in 1988. The first is a form of calligraphy that allows the artist only a single brush stroke. The other is a form of three-line poetry known as haiku in which the poet must follow this highly restrictive format: The first line has five syllables, the second line has seven syllables, and the third and final line has five syllables.  Artists who work in these media are set apart and defined by the restrictions to which they adhere. Their task is more difficult and the product of their efforts is therefore more highly esteemed. Should they fail to adhere to the restrictions then, de facto, they are no longer a member of that artistic group.

In like manner, we physicians have agreed to be restricted by the dictum of the Hippocratic oath, “First, Do No Harm.” Just as with this group of artists, we physicians have accepted the challenge of greater restrictions on our efforts to advance progress with new technology and clinical innovation. By agreeing to do no harm, we accept that we must find ways to accomplish progress without a significant overshoot, without harm. Ophthalmology is not permitted the cyclical approach to progress: three steps forward followed by two steps back. Note that this core principle does not preclude progress. It does, however, require that our progress unfold in smaller, more measured and well-verified steps.

When we succeed, we fulfill our contract to the patient and continue to earn the trust and higher esteem in which physicians have long been held. However, if we sidestep the more measured approach to progress, if we overreach and create a significant innovation overshoot, then we too are de facto, no longer members of our more select professional group. We risk losing that trust and esteem and will eventually be seen as little different from a sales force, which as we know has a different dictum: caveat emptor.

I am not at all anti-industry. I just want to shine a bright light on this crucial fact: Physicians and sales people are defined by different roles and different rules. Only we have the responsibility that accompanies patients’ trust because only we have taken the oath to protect them from harm, even as we advance progress.

So as we move now in earnest toward refractive lens exchange, I would like to appeal for a collective downshift to a lower gear. We may move slower, but as we have seen here, for us physicians that is exactly as it should be and as it must be if we are to continue to earn the trust and esteem that sets us apart.

"Dr. X, for every patient you send to our laser center, we'll collect the $5000 and we'll make sure you get back $2000."

"That's an extravagant amount," I said. "Isn't that a kickback?"

"So many people walk around with a meaningless life.  They seem half-asleep, even when they're busy doing things they think are important.  This is because they're chasing the wrong things.  Morrie Schwartz, "tuesdays with Morrie"

A few years ago, I stared at the growing stack of invitations, fliers, and letters in a pending file. Fliers to LASIK seminars.  Invitations to dinner with refractive surgeons and LASIK center directors.  Letters to get in on the ground level and invest in LASIK centers.

Out of curiosity, I accepted an invitation to dinner. I was wined and dined.  Take that back.  I was WINED and DINED.  Beneath the glow of dimmed chandeliers in an elegant restaurant, the compliments were blushingly effusive. I was made to feel so very special.  It was seductive.

The pitch came at the end of this dinner: Dr. X, for every patient you send to our laser center, we'll collect the $5000 and we'll make sure you get back $2000." "That's an extravagant amount," I said. "Isn't that a kickback?"  "No, we call it a co-management fee," was the quick reply.  "You and I will manage the patient together.  A "kickback" lands us both in jail. Hehehe."

That night, I told my husband, "I didn't take it personally, but now I know what it's like to be propositioned!  Optometry has never been paid that well for equivalent services. Call it anything.  A bribe is a bribe is a bribe. Do they really think that doctors are that easily bribed?"

Call me naive, but I was shocked, when within a year, so many doctors were climbing aboard the LASIK bandwagon. This was an experimental surgical procedure, very seat-of-the-pants, without a track record. The referral guidelines were sketchy. The scientific literature was sparse. Yet, knowing so little, they were enthusiastically referring patients to laser centers  --  up the proverbial KAZOO. 

With dismay, I witnessed the suspension of previously sound professional judgment, leading me to question:

Had the eye professions gone bonkers?  Were they not hearing the incessant LASIK ads as sheer, unadulterated HYPE?  Hype that trivialized the possible sight-impairing and sight-threatening complications?  Had my peers succumbed to a selective amnesia, forgetting basic cornea knowledge? A cut and partially vaporized cornea is compromised, no matter how you slice it.  Are we so easily bought?  Are we that "bunch of schlocks" that a professor-mentor had exhorted us NOT to be?

Doctors are human.  Oh, so human. And their inner children were being enticed with instant gratification.  Some resisted. Some sat on the fence.  Some yielded. LASIK coincided with a difficult time in my life.  My father was gravely ill.  Feeling down and vulnerable,  I seriously considered leaving my profession, perhaps returning to  teaching college psychology.

I felt ashamed to be a fellow member of the eye professions.  A growing number of its members were failing to profess, i.e., failing to fully inform their patients. I felt embarrassed by the flagrant disregard of  The Hippocratic Oath by those who were putting their own interests ahead of their patients'. I was appalled by the whole sordid "back-room" dealing that I had experienced... as if I were a hooker!  So ashamed, embarrassed, appalled -- and incredulous, I avoided the subject whenever it came up among peers.

Experiencing a sympathetic reaction called "Fight or Flight,"  my non-confrontative, peace-loving self chose to flee. I wanted OUT!  And fast.

My father loved living. His passions were reading and traveling, both sight-intensive activities. He lived life to the fullest, and at the end of it, I saw him fighting to keep every ounce of quality in his life. His valiant fight inspired me not to easily give up on what I loved so deeply:

I truly love those I serve; we have consciously cultivated a solid base of quality-minded patients who want the personalized care we offer and are willing to pay fair fees for it.  It has taken years to assemble the best team of conscientious, like-minded staff  members and doctors ever. Together, we have created a caring and joyful country practice in an impersonal, urban setting.  High-tech, from pouring most of its profits back into it, yet beautiful and welcoming, our office is a great place to be.  I love my profession, or at least I did a lot more before LASIK came along.

LASIK had become a fly in the ointment.

When my father crossed over, it was his faith in me and my faith in "I can do all things..." that motivated me to do my best to flick the fly out of the ointment and make a positive difference.

Not wishing to dwell on negative energy and resort to finger-pointing and blaming, I sought to clearly identify the fly in my ointment. If I were to flick it out, I needed to know what the fly was. Was LASIK the fly? No, it's just a procedure. Were doctors the flies? No, in an imperfect world, good and bad exist in every profession. Besides, judging others is a fruitless endeavor; I leave that stuff to a Higher Power.  Not my job. And then it came to me, clear as day:

The fly in the ointment was THE FAILURE TO FULLY INFORM: the ads and infomercials were not fully informing the public;  many refractive surgeons and referring doctors were not fully informing patients; and refractive surgeons were not fully informing referring doctors of their mounting failures.  Real risks and complications  were being downplayed, even trivialized.  Financial incentives for referring patients was not common knowledge. 

As professionals, we have a moral obligation to FULLY INFORM to the best of our ability, with the patients' best interests in mind.  Especially when it has to do with our primary sense, sight.

I began a personal campaign to persuade my peers to FULLY INFORM, to think twice before casually referring their patients to LASIK surgeons.  Whenever I attended meetings, conferences, or classes,  I'd bring the subject up with my peers, asking them to review their basic eye anatomy and pay attention to the corneal nerves -- the "feelers" of the eye, its biofeedback mechanism -- before they sent in their next patient. 

Reminding them of the neurotrophic function of these nerves (they help in the maintenance of a healthy cornea),  I reviewed how the microkeratome -- "the world's smallest buzz saw" -- sliced these microscopic nerves, millions of them, that do not grow back to its original state and function.

I'd offer the reality check, "Christopher Reeve still does not walk." Bless that courageous, inspiring man who struggles with dignity and fortitude. 

Quizzing my peers, I found that, for many, their knowledge was woefully lacking.  They were not FULLY INFORMED themselves, yet were referring patients. Some had no idea what "Sands of Sahara" was, much less knowing what to do about it if it bit them in their face.

Bringing up consequences that might broadside their pocketbooks, I hoped to make them think twice about their casual referrals:

"The surgeon's name is on the informed consent form, is yours? You do know that the surgeons have protected themselves from lawsuits with that informed consent form, but you're left yourself wide open for lawsuit for FAILURE TO FULLY INFORM. You can be held accountable. Complications, especially corneal transplants, can be expensive. If the surgeon's consent form is "iron-clad," you're the next logical person to sue."

I'd get replies like, "Geez, I never thought of that!"  Unfortunately, thought-provocation didn't seem to achieve my desired end of slowing down their rapturous, under-informed referrals.  In a short time, referring doctors were insisting on having their names added to informed consent forms. 

I'd toss out highly touted percentages of failure, which we belatedly know by personal experience as underestimations:

 "For the one, two or three patients out of every hundred you refer to LASIK surgery, the complications are not minor inconveniences, but profound losses in vision acuity, quality and even sight itself. Are you prepared to face that patient who will need a corneal transplant? Are you aware that when surgeries fail, patients, families, networks of friends, colleagues and co-workers suffer?  And all that for an elective surgery? What are you going to say to the patient who says, "Doc, I trusted you to do right by me.  Why didn't you tell me this could happen to me? Why did you make the complications seem so trivial and unlikely?  I would have thought twice..."

What about the losses in everyday function that are not even counted by the 1-3% statistic?  Those who no longer can work as they once did.  Who no longer read or travel as before LASIK? Who no longer drive safely at night? Those who are now plagued with glare, aberrations, starbursts, and halos (a combination of post-LASIK symptoms so common, it has its own acronym, GASH)? Those who suffer from dry eyes who now spend a $120 a month, $1200 a year for prescription artificial tears?  Would they have chosen this surgery if they had known that these complications would be theirs for keeps?

A common response was one of resignation: "X, if I don't send them in, someone else is going to do it anyway" or "Everyone else is doing it, and I don't want to be perceived as being behind the times." I'd gently remind them to review The Hippocratic Oath and The Golden Rule.  

Those overtly milking the LASIK cash cow responded with, "Hey, the money's too good not to refer,"  or "This is making a nice nest egg for my retirement."  To them, I was unapologetically pointed, "Hippocratic is not spelled  h-y-p-o-c-r-i-t-i-c."

In spite of my mild-mannered demeanor, when I smell a rat, especially a hurtful rat who has done a magnificent job of rationalization, I have no problem revealing that rat-ness to him/her self.  I practice The Golden Rule; darn it, if I'm being a hurtful rat without awareness, somebody tell me, so I can snap out of it!

Carrying the "FULLY INFORM" campaign on to the Internet, I e-mailed anyone and everyone in the eye professions. I suspect my e-mails were often deleted as SPAM.  I have a quick finger for it, myself.  For others, I suspect my e-mails were uncomfortable, unwelcome reality checks, but not uncomfortable enough to give up hefty fees. 

At first, the positive, supportive replies were a trickle; now, it is a steady stream. This has been a faith-restoring and heartening experience.  I am in honorable company after all; there are many who have refused to make light of our professions' duties and obligations. Thanks to the Internet, we are finding each other.  I especially like the replies that go: "I thought I was the only one who felt like you...You're right.  We did take an Oath, "First, do no harm...  What can we do?... Let's work on this together."

A grassroots effort to FULLY INFORM was born. 

Many of the refractive surgeons were not talking up their complications.  There was a FAILURE TO FULLY INFORM referring doctors who were feeding them patients.  Staying mum about their less than stellar results was good for business. Using the Snellen eye chart worked in their marketing favor.  A post-LASIK patient may have a significant decrease in visual acuities under low light conditions, but still be able to handily read a high-contrast eye chart, i.e., stark black letters projected on a stark white background.

Case in point: In March 2000, back in my home state,  I interviewed a post-LASIK patient,  Mary Doe, who related this experience to me:

"I'm not going to talk about me.  But I do have to be out of here by 5 o'clock, as I can't drive at night anymore.  I want to tell you about my friend, John Doe.  I'm talking for him, because he's not ready to talk about it yet.

I owe it to him to let you know what happened to him, because I persuaded him into doing the surgery with me.  From the get-go, I was doing great. I was out there  telling everyone, "Do it, do it, do it."  He was being quiet about it.   Some time later, I asked John how he was doing. He said, "Mary, I'm not doing so well. "Go back to the surgeon," I urged. "We have a lifetime guarantee on this. They can do a touch-up, an enhancement."

John said: "I did already.  The technician had me read a line on the chart.  I read it. The surgeon came in and said, "What are you doing here? You're doing great.  You just read the driver's test without glasses or contacts.  What's the problem?" I said, "Doc, like right now, how come when I reach down to tie my shoelaces, I can't see my shoelaces for my shoe?" The surgeon shook his head and said to me, "You need to see a psychiatrist."

Grrrrrr.

Hearing John's story, thanks to Mary,  gave me the push to do more. With crystal clarity, I had a moral obligation to FULLY INFORM her, FULLY INFORM him. I know, as any eye professional knows, the following: John's and Mary's refractive surgeon knew darn well that LASIK surgery had decreased John's ability to see in low light conditions, i.e., there was a reduction in contrast sensitivity.  No only was the surgeon being a complete a**, he was being totally dismissive of the patient's accurate reporting of a very real and common symptom of LASIK.  Yet, he led John to question his sanity.

A CONSCIOUS FAILURE TO FULLY INFORM.

Like Mary, John no longer drives at night.  Just as John can no longer see his white shoelaces on his white sneakers in a dimmed room, both can't easily see dark-colored cars and objects on dark roads (your kid hurrying home on a bike? your pet? your spouse jogging? your parent taking an evening stroll? you crossing a street?). Forget looking for matching socks in the morning. He no longer sees numbers well (print on colored paper is difficult), which is essential to his job. He's thinking about going on disability, and taxpayers will be paying to support him.  John's life has been complicated, let alone his eyes and vision. But that surgeon will count him and Mary as unmitigated successes.  And the failure rate will remain under-estimated,  deceptively misrepresenting the true numbers to the public, a failure to fully inform.

These days, we are busily FULLY INFORMING one another and the FDA.  We write, share, and collect our case reports on the LASIK failures. We're sending copies to one another, as well as forwarding copies to the FDA, along with our individual accounts of our personal experiences of backroom deals-making.

The FDA is listening
URL: http://www.surgicaleyes.org/ubboard/Forum27/HTML/001173.html

These days, we share tips on how to help post-LASIK patients who now seek our care. We learn from them and from caring doctors (like leukoma and DavOD) who generously and anonymously give of  their time and expertise to answer questions and contribute to a growing resource of fully informative accounts at http://surgicaleyes.com.  

Whenever one of us has access to the media, thanks to the power of the Internet, we strive to FULLY INFORM the public, e-mailing summaries of case reports, existing studies, and articles on complications.  We suggest interviews with complicated post-LASIK patients (with their permission and willingness,  of course) and refer to actual patient accounts at http://surgicaleyes.com.

The national, state, and local media are reading, listening, and using our information to FULLY INFORM the public in their articles, newscasts, and magazine shows. I am pleased to see that a number of my peers who were initially tempted are finding their way back to what attracted them to our profession in the first place: the caring and helping of people and the preservation of sight.  My faith in my profession is being restored.

Many are no longer sending their patients in for LASIK, realizing first-hand that LASIK is not ready for prime time.  We are all seeing more and more LASIK failures. Sobering failures. Many are discovering true "bigness," admitting to the casualness of  their early-on referrals and now educate their patients with the intent to FULLY INFORM.  They are apologizing to their patients, and are doing all they can to assist traumatized post-LASIK patients.

Many have come to realize, the hard way, that they "bit off more than they could chew,"  especially when their post-LASIK patients returned with unexpected complications, some irreversible.   Many more are taking classes like "How to Treat Post-LASIK Complications."  A hardbound text on the subject is now on the market, filled with photos of complicated REAL cases.  Nothing hypothetical or maybe about those damaged-for-life eyes.  We are also preparing ourselves for the long-term effects that will arise for many with age. For some of us, it's Humpty Dumpty time again. We wrangled with the down-the-road problems of RK -- remember that failed "miracle" eye surgery?  Been there, done that.  And here we go again. 

Many more are finding out that, when they consciously strive  to FULLY INFORM,  a common phenomenon occurs:  Patients do think twice.  Consciously thinking about what their sight is worth to them, patients make more carefully thought-out decisions, instead of headlong, emotionally-charged ones. Pondering the risks and the gamble involved with a cautious eye to the future,  they come to a full awareness that this is an elective, experimental surgery with the possibilities of significant eye- and life-complications and long-term problems...

They take that critical look before leaping.

AND once FULLY INFORMED, most patients are willing to wait for a less risky procedure, which will happen!  It's just not here quite yet. For a certain percentage when conventional means do not correct impaired vision, LASIK may make perfect sense.  Remember, this is not about a procedure; it is about FULLY INFORMING.

There are those occasional patients who have been brainwashed by the hype and do not wish to be fully informed, period. They are those who will listen and still decide to do it. We wish them nothing but success and well-being, and let them know that our door is always open for them.

Patients ultimately make their own decisions.  And we respect that right. This is America. There will always be those who live on the edge, sky-dive and climb Everest. The difference is they do so with full knowledge of the possibility of injury or death, no matter what the safety precautions.  Nature has its unforgiving quirks, its vagaries.  

Not FULLY INFORMED with the knowledge of the possibilities of injury or (sight) death, LASIK patients are not as prepared. Eyes are Nature's masterpieces.  Even with the best equipment in the most experienced of surgical hands, eyes can also be as quirky as Nature.

Common laments of those hurt by the FAILURE TO FULLY INFORM include: "Why wasn't I FULLY INFORMED that this could happen to me?"  "Why were the complications trivialized, glossed over?"  "I had no reality on the complications."  "I trusted my doctor to have my best interests in mind, and since, I've learned about the financial incentives to refer.  Why was this incentive-to-refer not disclosed to me? I would have thought twice!"

Fully informing the patients is simply the right thing to do!  

Those of us who are choosing to FULLY INFORM are making a difference, one person at  a time. One reporter at a time.  One news article at a time. One web page at a time. You will see more and more websites like this one, as more and more of my peers are recognizing the need to be heard, to FULLY INFORM

But all of this is not enough. And not in time for many

The irresponsible TV and radio ads, paid by those who wish to sustain their $100,000/day incomes, continue to lure, day in, day out. A percentage of under-informed patients WILL pay the steepest of prices with their sight and well-being by those who FAIL TO FULLY INFORM.  

Sadly, those with complications who were casually referred and/or poorly informed are the most embittered. Their primary sense has been compromised, serving as a daily reminder of a broken trust -- a sacred trust -- for the rest of their lives.

You are invited to join us. Please join us in being proactive in FULLY INFORMING the unwary public. We need your help.  We share the same public.  They need us to help. They are us.Writing this, I have done my best to keep my word impeccable. I am not too proud to beg on behalf of the gift of sight.  Thank you for your attention.

Kindl yours,
Dr. X

 

P.S. For those who have already done it, stay positive.  We do not wish to rain on your parade. We wish you no ill, ONLY continued success. Be aware. Stay informed, as several long-term problems are avoidable with early intervention.  Many of us doctors are back in school, taking classes to stem the tide of LASIK complications. Much of what we learn is news to us as doctors, and therefore news to you, as patients. Success has been attained in containing the sight-devastating "Sands of Sahara," which can "melt" the cornea.  Success has been attained with aggressive dry eye syndrome treatments to avoid corneal scarring, abrasion, and erosion, but better results are obtained when started early, when the symptoms may seem subtle and non-threatening. Sight is a cherished gift; do your best to preserve it the best way you can.

P.P.S.  Feel free to publish this.  Make copies, hand out them out.  Share its URL. No permission is needed.  Posted without a motive to derive financial gain, this is a public service to FULLY inform, plain and simple. 

This is a grassroots effort that's worth getting involved with, as it's about sight. For Heaven's 
Sake.

http://wakeup.to/lasik

FDA Consumer magazine

May-June 2005 Issue

http://www.fda.gov/fdac/features/2005/305_eye.html

By Michelle Meadows

 

Tears serve as a protective coating for the eyes. They keep the eyes moist, provide essential nutrients, and wash away dust and other particles. When the eyes don't produce enough tears or the right quality of tears, the result is a condition that doctors call keratitis sicca, popularly known as "dry eye."

Just as the name suggests, this condition makes the eyes feel dry, scratchy, and gritty. Other symptoms include burning, stinging, itching, pain, sensitivity to light, redness, blurry vision, and the feeling that there is a speck of dirt in the eye. There may also be a stringy discharge from the eyes. And though it may seem strange, dry eye can cause the eyes to water. "This can happen because the eyes are irritated," says Carolyn Begley, O.D., a professor of optometry at Indiana University in Bloomington. "You may experience excessive tearing the same way you would if something got in your eye."

But these tears won't necessarily make the eyes feel better. Reflex tears--the watery type that are produced in response to injury, irritation, or emotion--don't have the lubricating qualities necessary to prevent dry eye. Tear film is made of water, oil, and mucus, all of which are important for maintaining good eye health. The cornea, which covers the front of the eye, needs these tears continuously to protect it against infection. Most people who have dry eye experience mild irritation with no long-term effects, Begley says. But if the condition is left untreated or becomes severe, eye damage and vision loss can occur. Severe problems with dry eye can cause eye inflammation, corneal infection, and scarring.

"When dry eye symptoms are severe, they can interfere with quality of life," Begley says. "Some people may have trouble keeping their eyes open or they may not be able to work or drive." Fortunately, identifying the cause of the problem and seeking treatment early can make a big difference in easing the discomfort.

Common Causes

Aging is one of the most common causes of dry eye because tear production decreases as we get older. Dry eye affects more women than men because hormonal changes, such as those that occur in pregnancy, menstruation, and menopause, can decrease tear production. Environmental conditions also can play a role. Wind, heat, dust, air conditioning, cigarette smoke, and even hair dryers can make the eyes dry. Some people benefit from avoiding dusty, smoky areas, wearing sunglasses, and using a humidifier to moisten the surrounding air.

Another common culprit is not blinking enough, which happens during activities such as watching TV and computer use. "Each time you blink, it coats the eye with tears," Begley says. "You normally blink about every 12 seconds. But we've done studies of people playing computer games, and found that some people blinked once or twice in three minutes."

Begley says that about half of all people who wear contact lenses complain of dry eye. That's because soft contact lenses, which float on the tear film that covers the cornea, absorb the tears in the eyes. Dry eye also occurs or gets worse after LASIK and other refractive surgeries, in which the corneal nerves are cut during creation of a corneal flap. The corneal nerves stimulate tear secretion. Begley says, "If you've had dry eyes from wearing contact lenses or for any other reason and you are thinking about refractive surgery, this is something to consider."

Dry eye also can be caused by certain medications, including antihistamines, some antidepressants, birth control pills, nasal decongestants, and the prescription acne drug Accutane. And some autoimmune diseases, such as lupus, rheumatoid arthritis, and Sjögren's syndrome, can attack the tear glands.

Other diseases can also cause dry eye. For example, certain types of thyroid disease can interfere with blinking. Blepharitis, an inflammation of the eyelids, can interfere with the oil glands in the eyes.

Diagnosis and Treatment

 

Even though many treatments for dry eye are available without a prescription, it's wise to see a health care professional to evaluate the cause of the condition and to help you pick the best treatment.

 

Eye doctors use a combination of routine clinical exams and other specific tests for dry eye. For example, the Schirmer test uses a tiny strip of paper placed on the edge of the lower eyelids. "This measures how much moisture is in the eye, and it's also useful for determining the severity of the problem," Begley says. Doctors may also use dye, such as fluorescein or rose bengal, which is placed on the eye to stain the surface. This is to see how much the surface of the eye has been affected by dryness. Another test, tear break-up time (TBUT), measures the time it takes for tears to break up in the eye.

 

The first line of treatment for dry eye is usually over-the-counter demulcent drops, also known as artificial tears. These lubricate the eye and ease symptoms. Commonly found ingredients in these products include hydroxypropyl methylcellulose, the ingredient in Bion Tears and GenTeal, and carboxymethylcellulose, contained in Refresh Plus and Thera Tears. Always read the directions, but these products can generally be used as often as needed throughout the day.

 

Your health care professional can guide you in choosing the right one for you. "Some people use drops for red eyes, but that can make the eyes even more dry," Begley says. Red eyes could be caused by numerous factors, from allergies to an eye infection, which is why a proper diagnosis is important. If you wear contact lenses, use rewetting drops specifically for contact lenses. Other types of drops may contain ingredients that damage the lens.

 

Restasis (cyclosporine ophthalmic emulsion) is the only prescription product for chronic dry eyes. Approved by the Food and Drug Administration in 2002, the drug increases tear production, which may be reduced because of inflammation on the eye surface. In a clinical trial involving 1,200 people, Restasis increased tear production in 15 percent of patients, compared with 5 percent of patients in the placebo group, says Wiley Chambers, M.D., deputy director of the FDA's Division of Anti-Inflammatory, Analgesic and Ophthalmologic Drug Products.

 

Restasis is usually given twice a day, 12 hours apart. It should not be used by people with eye infections or hypersensitivity to the ingredients. It has not been tested in people with herpes viral infections of the eye. The most common side effect is a burning sensation. Other side effects may be eye redness, discharge, watery eyes, eye pain, foreign body sensation, itching, stinging, and blurred vision.

 

For people who have not found dry eye relief with drugs, punctal plugs may help. "These are reserved for people with moderate or severe dry eye when other medical treatment hasn't been adequate," says Eva Rorer, M.D., a medical officer in the FDA's Division of Ophthalmic and Ear, Nose, and Throat Devices.

In each eye, there are four puncta, little openings that drain tears into the tear ducts. Punctal plugs are inserted into the puncta to block tear drainage. Some doctors try out temporary ones made of collagen first to make sure that permanent ones will not cause excessive tearing. Permanent plugs are usually made of silicone. In recent years, Rorer says, some plugs have been approved that are made of thermally reactive material. "Some of these are inserted into the punctum as a liquid and then they harden and conform to the individual's drainage system." Others start out rigid and become soft and flexible, adapting to the individual's punctal size after they are inserted. Artificial tears are usually still required after punctal plug insertion."

 

The risks of punctal plugs are fairly minimal," Rorer says. "There is a risk of eye irritation, excessive tearing, and, in rare cases, infection."

Am J Ophthalmol. 2006 Apr;141(4):758-60.   

McCulley JP, Aronowicz JD, Uchiyama E, Shine WE, Butovich IA.  Department of Ophthalmology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 

PURPOSE: To establish scientific relationship between relative humidity (RH) and aqueous tear evaporation to elucidate possible significance of this relationship in normals and aqueous tear deficiency patients.  

DESIGN: Prospective experimental laboratory study.  

METHODS: Ocular surface evaporation was determined using evaporometry and calculated for two ranges of RH, 25% to 35%, and 35% to 45% in a randomized clinical patient population.  

RESULTS: Average evaporative rate in the higher humidity range was between 0.029 +/- 0.009 through 0.043 +/- 0.016 mul/cm(2)/min. At lower humidity, range was between 0.044 +/- 0.013 through 0.058 +/- 0.018 mul/cm(2)/min. Differences in the corresponding evaporative rates were statistically significant (between P < .003 through P < .043) for each analysis.  

CONCLUSIONS: A decrease of 10% RH resulted in an average difference of between 28.33% to 59.42% increase in evaporation. The increase in evaporation at lower humidity has significant clinical implications for patients with aqueous deficient dry eyes, and possibly those undergoing laser-assisted in situ keratomileusis (LASIK).

Am J Ophthalmol. 2006 Mar;141(3):438-45.

De Paiva CS, Chen Z, Koch DD, Hamill MB, Manuel FK, Hassan SS, Wilhelmus KR, Pflugfelder SC.

Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas.

PURPOSE: To determine the incidence of dry eye and its risk factors after myopic laser-assisted in situ keratomileusis (LASIK).

DESIGN: Single-center, prospective randomized clinical trial of 35 adult patients, aged 24 to 54 years, with myopia undergoing LASIK.

METHODS: setting and study population: Participants were randomized to undergo LASIK with a superior or a nasal hinge flap. They were evaluated at 1 week and 1, 3, and 6 months after surgery. intervention: Bilateral LASIK with either a superior-hinge Hansatome microkeratome (n = 17) or a nasal-hinge Amadeus microkeratome (n = 18). main outcome measures: The criterion for dry eye was a total corneal fluorescein staining score >/=3. Visual acuity, ocular surface parameters, and corneal sensitivity were also analyzed. Cox proportional-hazard regression was used to assess rate ratios (RRs) with 95% confidence intervals.

RESULTS: The incidence of dry eye in the nasal- and superior-hinge group was eight (47.06%) of 17 and nine (52.94%) of 17 at 1 week, seven (38.89%) of 18 and seven (41.18%) of 17 at 1 month, four (25%) of 16 and three (17.65%) of 17 at 3 months, and two (12.50%) of 16 and six (35.29%) of 17 at 6 months, respectively. Dry eye was associated with level of preoperative myopia (RR 0.88/each diopter, P = .04), laser-calculated ablation depth (RR 1.01/mum, P = 0.01), and combined ablation depth and flap thickness (RR 1.01/mum, P = 0.01).

CONCLUSIONS: Dry eye occurs commonly after LASIK surgery in patients with no history of dry eye. The risk of developing dry eye is correlated with the degree of preoperative myopia and the depth of laser treatment.

Clin Exp Optom. 2005 Mar;88(2):89-96.

comparison of outcomes for Asian and Caucasian eyes.

Albietz JM, Lenton LM, McLennan SG.

Queensland University of Technology, Brisbane, Australia.

BACKGROUND: Dry eye is a common complication of LASIK surgery. Our clinical impression was that post-LASIK dry eye was more problematic for our Asian patients. The aim of this study was to determine if dry eye after LASIK is more prevalent, more sustained and more severe in Asian eyes compared with Caucasian eyes.

METHODS: This study was based on a retrospective analysis of a clinical database. Data (n = 932 eyes, 932 patients) was collected before and after (week 2 and months 1, 3 and 6) LASIK surgery. Patients were defined as Asian if both parents were of East Asian ethic origin. Assessments included dry eye symptoms, ocular surface staining, tear volume, tear secretion, tear film stability and corneal sensation.

RESULTS: Asian eyes had greater ocular surface staining, poorer tear film stability and lower tear volume before LASIK and at all times after LASIK. Dry eye symptoms occurring 'often or constantly' were more prevalent at all time points after LASIK in Asian eyes. Chronic dry eye persisting six months or more after LASIK was diagnosed in 28 per cent of Asian eyes and 5 per cent of Caucasian eyes (p < 0.001). Asian patients with chronic dry eye were predominantly female, reported dry eye symptoms, had greater ocular surface staining and lower tear secretion, stability and volume before surgery. After LASIK, Asian eyes had a slower return to pre-operative values for ocular surface staining, tear volume and corneal sensation.

DISCUSSION: The risk of chronic dry eye after LASIK was significantly higher in Asian eyes. Contributing factors could include racial differences in eyelid and orbital anatomy, tear film parameters and blinking dynamics and higher attempted refractive corrections in Asian eyes.Chronic dry eye and regression after laser in situ keratomileusis for myopia.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15050267&query_hl=1

 

J Cataract Refract Surg. 2004 Mar;30(3):675-84.

Albietz JM, Lenton LM, McLennan SG.

Centre for Eye Research, Queensland University of Technology, Kelvin Grove, Australia.

 

PURPOSE: To examine the relationship between chronic dry eye and refractive regression after laser in situ keratomileusis (LASIK) for myopia.

SETTING: Excimer Laser Vision Centre and Centre for Eye Research, Queensland University of Technology, Brisbane, Australia.

METHODS: This study was based on a retrospective analysis of a clinical database and a case study series. Data (N = 565 eyes) were collected before and after (2 weeks and 1, 3, 6, and 12 months) LASIK. Three case studies, which highlight appropriate management strategies for LASIK candidates with dry eye, are presented.

RESULTS: Regression after LASIK was related to chronic dry eye. It occurred in 12 (27%) of 45 patients with chronic dry eye and in 34 (7%) of 520 patients without (P<.0001). Patients with chronic dry eye had significantly worse myopic outcomes than those without (1 month, P =.02; 3 months, P =.01; 6 months, P =.004; 12 months, P =.008). The risk for chronic dry eye was significantly associated with female sex, higher attempted refractive correction, greater ablation depth, and the following pre-LASIK variables: increased ocular surface staining; lower tear volume, tear stability, and corneal sensation; and dry-eye symptoms before LASIK. The risk for regression was significantly associated with higher attempted refractive correction, greater ablation depth, and dry-eye symptoms after LASIK. Case studies demonstrated that intensive dry-eye treatment may improve the refractive outcome and alleviate the need for enhancement surgery.

CONCLUSION: The risk for refractive regression after LASIK was increased in patients with chronic dry eye.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16447938&query_hl=1&itool=pubmed_docsum

J Refract Surg. 2006 Jan-Feb;22(1):61-6.

Noda-Tsuruya T, Asano-Kato N, Toda I, Tsubota K.

Minamiaoyama Eye Clinic, Tokyo, Japan.

PURPOSE: To evaluate the efficacy of autologous serum eye drops for dry eye after LASIK in a prospective, randomized study.

METHODS: Fifty-four eyes of 27 male patients who underwent LASIK were divided into two groups; patients who used autologous serum eye drops and those who used artificial tears postoperatively. Schirmer test with anesthesia, tear break-up time (BUT), and rose bengal and fluorescein staining for the ocular surface were prospectively compared between the groups. All values were also compared before and after surgery (at 1 week [except for Schirmer test], 1 month, 3 months, and 6 months) in each group.

RESULTS: Tear BUT was greater in the autologous serum eye drops group than in the artificial tears group at 6 months postoperatively. Rose bengal score was lower in patients using autologous serum eye drops than in patients using artificial tears at 1 month and 3 months postoperatively. No significant difference was noted between patients using autologous serum eye drops and patients using artificial tears in the value of Schirmer test with anesthesia and fluorescein scores. In the autologous serum eye drops group, tear BUT was increased at 3 months after LASIK, rose bengal score was lower at 1 month and 3 months, and fluorescein score was lower at 1 month after LASIK compared to preoperative values, respectively. In the artificial tears group, all values (Schirmer test, tear BUT, rose bengal score, and fluorescein score) showed no differences between before and after LASIK. No differences were noted in the subjective scores for dryness between the autologous serum eye drops and artificial tears groups.

CONCLUSIONS: The autologous serum eye drops group showed prolongation of the tear BUT and a reduction in rose bengal staining score.

http://www.ncbi.nlm.nih.gov/entrez/..1627&query_hl=6

 

J Cataract Refract Surg. 2001 Apr;27(4):577-84.
 
Hovanesian JA, Shah SS, Maloney RK.

Jules Stein Eye Institute and the Department of Ophthalmology, UCLA
School of Medicine, Los Angeles, California, USA.

 

PURPOSE: To determine the incidence and severity of patient complaints typical of dry eye and recurrent erosion syndrome after excimer laser refractive surgery and to compare the incidence of these symptoms after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).



SETTING: Outpatient university practice.



METHODS: A questionnaire was mailed to 1731 patients who had had primary myopic PRK or LASIK at least 6 months previously. Questions were designed to determine the incidence and character of ocular dryness and recurrent erosion symptoms and their impact on patient satisfaction and willingness to have surgery again. Responses from PRK and LASIK patients were compared.

 

RESULTS: Responses from 231 PRK patients and 550 LASIK patients revealed an incidence of dryness symptoms in 43% and 48%, respectively (P >.05). Soreness of the eye to touch was reported by 26.8% and 6.7%, respectively (P <.0001). Sharp pains occurred in 20.4% of PRK patients and 8.0% of LASIK patients (P =.0001). Complaints of the eyelid sticking to the eyeball occurred in 14.7% and 5.6%, respectively (P =.0001). All symptoms occurred predominantly on waking. Frequency of eyelid sticking (P <.0005) and sharp pain (P <.005) symptoms, as well as severity of sharp pain symptoms (P <.0001), were significantly greater in PRK patients than in LASIK patients. On a scale of 0 to 10 (10 high), median overall patient satisfaction with surgery was 9 in both groups. Soreness of the eyelid to touch occurred significantly more frequently among patients with symptoms of sharp pains on waking (P <.001) and the sensation of the eyelid sticking to the eyeball (P <.001). Patients with 1 or more symptoms were twice as likely as asymptomatic patients to have a satisfaction score of less than 8 (P <.001).



CONCLUSIONS: Ocular dryness symptoms occurred commonly after PRK and LASIK. Symptoms suggestive of mild recurrent erosions included sharp pains, the sensation of the eyelid sticking to the eyeball, and soreness of the eyelid to touch, a previously unrecognized symptom of this condition. These symptoms occurred commonly after excimer laser procedures but were significantly more common, more severe, and more prolonged after PRK. The presence of these symptoms had a significant effect on patient satisfaction.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11311627&query_hl=6

 

Abstract

 

PURPOSE: To determine the incidence and severity of patient complaints typical of dry eye and recurrent erosion syndrome after excimer laser refractive surgery and to compare the incidence of these symptoms after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).

 

SETTING: Outpatient university practice.

 

METHODS: A questionnaire was mailed to 1731 patients who had had primary myopic PRK or LASIK at least 6 months previously. Questions were designed to determine the incidence and character of ocular dryness and recurrent erosion symptoms and their impact on patient satisfaction and willingness to have surgery again. Responses from PRK and LASIK patients were compared.

 

RESULTS: Responses from 231 PRK patients and 550 LASIK patients revealed an incidence of dryness symptoms in 43% and 48%, respectively (P >.05). Soreness of the eye to touch was reported by 26.8% and 6.7%, respectively (P <.0001). Sharp pains occurred in 20.4% of PRK patients and 8.0% of LASIK patients (P =.0001). Complaints of the eyelid sticking to the eyeball occurred in 14.7% and 5.6%, respectively (P =.0001). All symptoms occurred predominantly on waking. Frequency of eyelid sticking (P <.0005) and sharp pain (P <.005) symptoms, as well as severity of sharp pain symptoms (P <.0001), were significantly greater in PRK patients than in LASIK patients. On a scale of 0 to 10 (10 high), median overall patient satisfaction with surgery was 9 in both groups. Soreness of the eyelid to touch occurred significantly more frequently among patients with symptoms of sharp pains on waking (P <.001) and the sensation of the eyelid sticking to the eyeball (P <.001). Patients with 1 or more symptoms were twice as likely as asymptomatic patients to have a satisfaction score of less than 8 (P <.001).

 

CONCLUSIONS: Ocular dryness symptoms occurred commonly after PRK and LASIK. Symptoms suggestive of mild recurrent erosions included sharp pains, the sensation of the eyelid sticking to the eyeball, and soreness of the eyelid to touch, a previously unrecognized symptom of this condition. These symptoms occurred commonly after excimer laser procedures but were significantly more common, more severe, and more prolonged after PRK. The presence of these symptoms had a significant effect on patient satisfaction.

 

 

 

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed

Ophthalmology. 2001 Jul;108(7):1230-5 
Effects of laser in situ keratomileusis on tear production, clearance, and the ocular surface.

Battat L, Macri A, Dursun D, Pflugfelder SC.
Bascom Palmer Eye Institute, University of Miami School of Medicine, Miami, Florida, USA.Excerpts from the full text:

 

 

 - Corneal sensation remained reduced 16 months after LASIK 

 - Conjunctival sensation remained reduced 16 months after LASIK 

 - Tear clearance remained reduced 16 months after LASIK.

SOURCE

 

BARCELONA - Regardless of how thick or thin LASIK flaps are made, the flaps cause a considerable reduction in corneal biomechanical stability compared with surface ablation procedures, according to a study presented here.

 

"Taking into account biomechanical properties but also visual recovery time and quality of vision, the best option is epi-LASIK, according to our results," Jorge Cazal, MD, said at the winter meeting of the European Society of Cataract and Refractive Surgeons.

In a study conducted at CIMA Eye Clinic, two groups of 25 patients were randomly assigned to undergo epi-LASIK with the Moria Epi-K epikeratome in one eye and PRK or thin-flap LASIK in the other eye.

"At 6 months postoperatively, the LASIK eyes experienced a 48% reduction in corneal biomechanics, while the eyes that underwent surface ablation had only a decrease between 10% and 14%," Dr. Cazal said.

"At 6 months, the LASIK group had the highest induction of high-order aberrations, with [root mean square] of 0.73, compared with 0.25 for the epi-LASIK group," he said.

However, visual recovery was fastest with LASIK, followed by epi-LASIK and PRK. Pain scores were also lowest with LASIK, followed by epi-LASIK and PRK, he noted.

Journal of Refractive Surgery Vol. 23 No. 6 June 2007

Richard M. Davis, MD; Jason A. Evangelista, MD

 

 

PURPOSE: To evaluate whether the vacuum of a microkeratome suction ring induces ocular structure changes.

 

METHODS: A prospective case series using A-scan ultrasonography to measure anterior chamber depth, lens thickness, vitreous body, and axial length was performed. Measurements before and during application of a Hansatome microkeratome suction ring were performed on 69 eyes of 39 consecutive patients scheduled to undergo a first-time LASIK procedure with mechanical creation of a corneal flap.

 

RESULTS: Mean patient age was 43±12.1 years. Of the 69 eyes, 63 (91.3%) had refractive myopia with a mean spherical equivalent refraction of –2.93±1.56 diopters (D) and 6 (8.7%) had refractive hyperopia with a mean spherical equivalent refraction of 1.37±0.31 D. Overall, the mean spherical equivalent refraction of all eyes was –2.56±1.94 D. Ultrasound measurements during suction revealed a decrease in the anterior chamber depth of –0.06±0.36 mm (P<.05) and lens thickness by –0.14±0.45 mm (P<.05) whereas the vitreous body increased 0.25±0.36 mm (P<.05). Although insignificant, a trend toward increasing axial length was noted. No measurements changed over time during the application of vacuum.

 

CONCLUSIONS: Vacuum by a microkeratome suction ring induced a compression of the anterior chamber and lens with commensurate expansion of the vitreous body. The assessment of vacuum effects during LASIK suggests that measurements of intraocular compartments are more informative than axial length. [J Refract Surg. 2007;23:563-566.]

 

 

From the full text:

Quote: Before the application of the excimer laser in LASIK, vacuum is applied to the external surface of the eye by a suction ring in the form of a microkeratome or a femtosecond laser to assist with the creation of a lamellar corneal fl ap. The vacuum may increase the intraocular pressure (IOP) to >90 mmHg in less than 5 seconds, which could induce vitreoretinal changes.

Quote: Although the limiting factor of using A-scan ultrasonography for lens thickness and using mathematical formulations to calculate vitreous body measurements are acknowledged, our study has conclusively shown compression of the anterior structures with elongation of the vitreous body and a trend of increasing axial length (P=.057). We have illustrated the changes to be more complex than previously reported as the anterior and posterior structures respond differently to high vacuum making the axial length measurement less illuminating. Although the clinical significance has yet to be determined, biomechanical deformation by a rapid sequence of compression and decompression associated with LASIK theoretically may increase the risk of vitreoretinal pathology.

J Cataract Refract Surg. 2003 Apr;29(4):825-31.

Viestenz A, Langenbucher A, Hofmann-Rummelt C, Modis L, Viestenz A, Seitz B.

Department of Ophthalmology, University of Erlangen-Nurnberg, Germany. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

PURPOSE: To evaluate flap dimensions and cut quality with repeated blade use of the automated Summit Krumeich-Barraquer microkeratome (SKBM [LadarVision]).

 

SETTING: Department of Ophthalmology, University Erlangen-Nuremberg, Erlangen, Germany.

 

METHODS: The SKBM (160 microm plate, intended flap diameter 9.0 mm) was used to perform a corneal hinged flap in 35 pig cadaver eyes. Seven blades were reused 5 times each. The flap diameter was measured by planimetry, and the thickness was assessed by ultrasonic pachymetry. Scanning electron microscopy (SEM) of blades and stromal beds was performed.

 

RESULTS: With single use of the blade, the mean central flap thickness was 145 microm +/- 25 (SD). The vertical/horizontal flap diameter was 9.0 +/- 0.03 mm/8.6 +/- 0.03 mm. No thickness gradient was observed from the incision (138 +/- 31 microm) to the flap hinge (130 +/- 30 microm). If the blade was used more than 2 times, the flap was thinner at the incision (157 +/- 34 microm versus 124 +/- 20 microm; P =.003) and the hinge (143 +/- 24 microm versus 122 +/- 31 microm; P =.04), but the central thickness remained unchanged. With multiple use of the blade, SEM analysis showed increasing cut irregularity, more tissue remnants on the blade surface, and a progression in blade irregularities (up to 9.3 microm).

 

CONCLUSIONS: Reproducible flap size and thickness can be obtained with single use of stainless steel blades in the SKBM. With multiple use, the quality of the blades and the stromal bed deteriorates and the peripheral thickness of the flaps decreases. Thus, single use of blades is recommended.

After LASIK With Microkeratome and Femtosecond Laser Created Flaps

 

JOURNAL OF REFRACTIVE SURGERY 2007; 23(3):233

By Bryan C. Hainline, MD; Marianne O. Price, PhD; David M. Choi, MD; Francis W. Price, Jr., MD

 

 

PURPOSE: To report nine cases of severe central flap inflammation and necrosis after LASIK.

 

METHODS: A retrospective chart review was conducted on 17,100 LASIK cases performed at two laser centers in Indiana from January 1995 through May 2005. All patients with central lamellar flap necrosis were identified.

 

RESULTS: Severe central flap inflammation and necrosis occurred in nine eyes of eight patients. Six patients underwent flap creation with a mechanical microkeratome and two with a femtosecond laser. Of eight eyes with >2- month follow-up, one lost at least two lines of best spectacle- corrected visual acuity and two experienced a hyperopic shift in spherical equivalent refraction. Typically, inflammation was minimal the day after surgery, peaked 5 to 10 days later, and subsided by 60 days. Six of nine cases were treated by lifting the flap and irrigating the stromal bed. In each of these cases, few or no inflammatory cells were observed in the stromal bed, the posterior flap surface was intact, and the central portion of the anterior flap had a jelly-like consistency.

 

CONCLUSIONS: Central lamellar flap necrosis appears to differ from diffuse lamellar keratitis because the location of stromal inflammation is not in the flap interface but rather in the flap anterior stroma. Treatment with corticosteroids seemed to have little effect on outcomes. This is thought to be the first documentation of central lamellar flap necrosis following the use of a femtosecond laser. [J Refract Surg. 2007;23:233-242.]

M.S. Sridhar, Christopher J. Rapuano, and Elisabeth J. Cohen;  Cornea Service, Wills Eye Hospital, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, USA; *Inquiries to Christopher J. Rapuano, MD, Cornea Service, Wills Eye Hospital, 900 Walnut St, Philadelphia, PA 19107; fax: (215) 928-3854
Manuscript accepted 24 May 2001;

 

 

PURPOSE: To report a rare complication in which the patient accidentally removed the laser in situ keratomileusis corneal flap.

 

METHODS: Interventional case report. A 35-year-old woman underwent uncomplicated laser in situ keratomileusis surgery. Ten days after surgery, she inserted a soft contact lens into the right eye to improve her vision. She tried to remove the contact lens, but had pain and bleeding. She was referred 10 days later with a diagnosis of loss of flap.

 

RESULTS: On examination, she had a best-corrected visual acuity of 20/70 in the right eye. The right eye examination revealed no corneal flap, mild corneal edema, and significant haze. A central epithelial defect was found.

 

CONCLUSION: Accidental corneal flap removal can rarely follow laser in situ keratomileusis surgery. This complication provides insight into the weak adhesion of the flap onto the stromal bed after laser in situ keratomileusis surgery and, hence, the inherent risk of traumatic flap dislocation or amputation, which needs to be explained to the patient.

...repeat laser in situ keratomileusis in myopic patients

 

J Cataract Refract Surg. 2006 Dec;32(12):2080-4.

Das S, Sullivan LJ.

From the Royal Victorian Eye and Ear Hospital (Das, Sullivan) and the Melbourne Excimer Laser Group (Sullivan), East Melbourne, Australia.

 

 

PURPOSE: To compare the change in residual stromal thickness and flap thickness between primary laser in situ keratomileusis (LASIK) and repeat LASIK in myopic patients.

 

SETTING: Melbourne Excimer Laser Group, East Melbourne, Australia.

 

METHODS: This retrospective nonrandomized comparative trial comprised 46 eyes of 34 patients who had repeat LASIK. The thickness of the residual stromal bed was calculated by subtracting the calculated stromal ablation from pachymetry of the stromal bed after cutting the flap in primary treatment and directly measuring during retreatment. The thickness of the LASIK flap in primary and repeat LASIK was calculated by subtracting the central pachymetry of the stromal bed after creating the flap from pachymetry before cutting and lifting the flap, respectively. The main outcome measures were comparison of the residual stromal bed and flap thickness between the primary treatment and the retreatment.  

 

RESULTS: The mean thickness of the calculated residual stromal bed after primary treatment was 329.8 mum +/- 40.8 (SD), and the mean measured residual stromal bed at retreatment was 317.3 +/- 42.8 mum. The mean difference in residual stromal bed thickness was 12.5 +/- 13.0 mum (P<.001). Sixteen eyes (34.7%) had a decrease in bed thickness between 11 mum and 20 mum. The mean flap thickness during primary LASIK and repeat LASIK was 145.2 +/- 17.1 mum and 169 +/- 18.3 mum, respectively. The mean interval between primary treatment and retreatment was 7.4 +/- 4.1 months. The mean change in flap thickness was 23.8 +/- 15.2 mum (P<.001). Fifteen eyes (32%) had an increase in flap thickness between 11 mum and 20 mum. There was a negative correlation between refractive error before primary treatment and the difference in flap thickness. No correlation was found between the difference in flap thickness and the interval between the primary treatment and the repeat treatment.

 

CONCLUSIONS: Intraoperative pachymetry of the stromal bed during retreatment is strongly recommended as the residual stromal bed and flap thickness changes between primary and retreatment. There is a tendency for the measured stromal bed at retreatment to be thinner than the calculated stromal bed and for the flap to be thicker than previously measured.

J Refract Surg. 2006 Nov;22(9):884-9.

Landau D, Levy J, Solomon A, Lifshitz T, Orucov F, Strassman E, Frucht-Pery J.

Cornea and Refractive Surgery Unit, Dept of Ophthalmology, Hadassah University Hospital, P.O.B. 12000, Jerusalem 91120, Israel. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

PURPOSE: To report our experience treating eye trauma after LASIK refractive surgery.

 

METHODS: Nine eyes of eight patients (one woman and seven men) were treated for ocular trauma: blunt trauma (n=5), sharp instrument trauma (n=2,) and trauma from inflation of automobile air bags during a traffic accident (n=2). The time from LASIK varied between 3 months and 6 years. All patients were hospitalized as a result of severe decrease in visual acuity and pain.

 

RESULTS: Seven of nine LASIK flaps had some degree of dislocation and were lifted, irrigated, and repositioned. Two flaps were edematous without dislocation. Intensive topical steroids and antibiotics were used in all patients up to 3 weeks after trauma. Three months after trauma, five eyes regained their pre-trauma visual acuity (between 20/20 and 20/40), and three eyes lost one line of best spectacle-corrected visual acuity.

 

CONCLUSIONS: Trauma occurring several months or years after LASIK may cause flap injury. Adequate and prompt treatment usually is successful.

 

Our report, as well as the related literature, indicates that the healing of the flap is incomplete even 6 years after LASIK surgery. The exact mechanism of long-term adhesion remains unclear. In an animal model, Maurice and Monroe20 demonstrated that after creation of a lamellar corneal stromal dissection, the adhesive force of the healed stroma lamellae approximated one-quarter to one-half that of normal. Perez et al21,22 suggested that drying increases stromal-stromal adhesion due to the increased concentration of surface molecules, which have high ionic charge densities and ionic binding. In rabbit corneas, the wound healing reaction after LASIK takes place only at the periphery of the microkeratome wound, leaving the central optical zone clear; similar findings have been described in human eyes after LASIK.

 J Refract Surg. 2006 Apr;22(4):402-4. 

Cheung LM, Papalkar D, Versace P. 

Department of Ophthalmology, Prince of Wales Hospital, Randwick, Australia. 

 

 

PURPOSE: To report a case of traumatic flap dehiscence and Enterobacter keratitis 34 months after LASIK. 

 

METHODS: A 36-year-old man sustained a flap dehiscence following traumatic right eye gouging by a seagull claw. He presented the following day with uncorrected visual acuity (UCVA) in the affected eye of 3/200 and organic foreign body deposits underneath the flap. Systemic and topical antibiotics were administered and urgent surgical debridement and replacement of the LASIK flap was performed. An Enterobacter species was cultured from an intraoperative swab. 

 

RESULTS: After a prolonged postoperative course, including administration of topical ofloxacin, tobramycin, chloramphenicol, and dexamethasone, UCVA returned to 20/20. 

 

CONCLUSIONS: Good visual outcome after early debridement and appropriate antibiotics was achieved. Patients should be injury advised to seek prompt ophthalmic consultation after LASIK.

Am J Ophthalmol. 2001 Nov;132(5):780-2.

 

Sridhar MS, Rapuano CJ, Cohen EJ.  Cornea Service, Wills Eye Hospital, Jefferson Medical College of Thomas Jefferson University, Philadelphia, Pennsylvania, USA.  

 

PURPOSE: To report a rare complication in which the patient accidentally removed the laser in situ keratomileusis corneal flap.

 

 

METHODS: Interventional case report. A 35-year-old woman underwent uncomplicated laser in situ keratomileusis surgery. Ten days after surgery, she inserted a soft contact lens into the right eye to improve her vision. She tried to remove the contact lens, but had pain and bleeding. She was referred 10 days later with a diagnosis of loss of flap.

 

 

RESULTS: On examination, she had a best-corrected visual acuity of 20/70 in the right eye. The right eye examination revealed no corneal flap, mild corneal edema, and significant haze. A central epithelial defect was found.

 

 CONCLUSION: Accidental corneal flap removal can rarely follow laser in situ keratomileusis surgery. This complication provides insight into the weak adhesion of the flap onto the stromal bed after laser in situ keratomileusis surgery and, hence, the inherent risk of traumatic flap dislocation or amputation, which needs to be explained to the patient.

Cohesive Tensile Strength of Human LASIK Wounds With Histologic, Ultrastructural, and Clinical Correlations

Journal of Refractive Surgery Vol. 21 No. 5 September/October 2005

Ingo Schmack, MD; Daniel G. Dawson, MD; Bernard E. McCarey, PhD; George O. Waring III, MD, FACS, FRCOphth; Hans E. Grossniklaus, MD; Henry F. Edelhauser, PhD

 

SOURCE

 

PURPOSE: To measure the cohesive tensile strength of human LASIK corneal wounds.

 

METHODS: Twenty-five human eye bank corneas from 13 donors that had LASIK were cut into 4-mm corneoscleral strips and dissected to expose the interface wound. Using a motorized pulling device, the force required to separate the wound was recorded. Intact and separated specimens were processed for light and electron microscopy. Five normal human eye bank corneas from 5 donors served as controls. A retrospective clinical study was done on 144 eyes that had LASIK flap-lift retreatments, providing clinical correlation.

 

RESULTS: The mean tensile strength of the central and paracentral LASIK wounds showed minimal change in strength over time after surgery, averaging 2.4% (0.72 ± 0.33 g/mm) of controls (30.06 ± 2.93 g/mm). In contrast, the mean peak tensile strength of the flap wound margin gradually increased over time after surgery, reaching maximum values by 3.5 years when the average was 28.1% (8.46 ± 4.56 g/mm) of controls. Histologic and ultrastructural correlative studies found that the plane of separation always occurred in the lamellar wound, which consisted of a hypocellular primitive stromal scar centrally and paracentrally and a hypercellular fibrotic stromal scar at the flap wound margin. The pathologic correlations demonstrated that the strongest wound margin scars had no epithelial cell ingrowth—the strongest typically being wider or more peripherally located. In contrast, the weakest wound margin scars had epithelial cell ingrowth. The clinical series demonstrated the ability to lift LASIK flaps without complications during retreatments up to 8.4 years after initial surgery, correlating well with the laboratory results.

 

CONCLUSIONS: The human corneal stroma typically heals after LASIK in a limited and incomplete fashion; this results in a weak, central and paracentral hypocellular primitive stromal scar that averages 2.4% as strong as normal corneal stroma. Conversely, the LASIK flap wound margin heals by producing a 10-fold stronger, peripheral hypercellular fibrotic stromal scar that averages 28.1% as strong as normal corneal stromal, but displays marked variability. [J Refract Surg. 2005;21:433-445.]

 The LASIK flap never heals

 

 

WebMDHealth: http://my.webmd.com/content/article/61/68084.htm

Tosi GM, Tilanus MA, Eggink C, Mittica V.

WebMDHealth on flap never healing  

   

The LASIK flap never heals… the LASIK flap can be easily dislodged from simple contact with the eye such as a finger poke.

 

J Cataract Refract Surg. 2001 May;27(5):781-3.

Traumatic flap displacement and subsequent diffuse lamellar keratitis after laser in situ keratomileusis.

Schwartz GS, Park DH, Schloff S, Lane SS.

Associated Eye Care, Lake Elmo, Minnesota 55042, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Late Traumatic Flap Dislocations After LASIK

 

 

J Cataract Refract Surg Vol 22, May 2006

 

http://www.journalofrefractivesurgery.com/showAbst.asp?thing=12869

 

 

 

Excerpts from the full text:

 

A number of cases of late onset traumatic LASIK flap dislocations have been reported, raising questions about the  strength of the adhesion between the flap and the stromal bed.

 

In this series, we report three cases of late onset traumatic  LASIK flap displacement and their management. One patient presented 7 years after the initial surgery, which, to our knowledge, is the longest duration reported.

 

A 23-year-old man with bilateral uncomplicated LASIK 7 years prior presented 2 days after sustaining a left eye injury by another person’s fingernail in a fight.

 

A 33-year-old woman underwent LASIK and presented after sustaining a broomstick injury 1 year postoperatively.

 

A 38-year-old woman with a history of uncomplicated bilateral LASIK 2 years before sustained a right eye injury when a folder fell from a shelf.

 

The creation of a lamellar flap results in a potential plane of weakness in the cornea in which shearing forces can produce flap displacement. Recent  histological and confocal studies have shown a central hypocellular primitive scar in the interface, allowing easy lifting of the flap in trauma.

 

The fact that this potential plane can be disrupted many years after LASIK (7 years after the initial surgery in patient 1) indicates that corneal integrity is compromised by the surgical procedure and takes a long time, if ever, to restore.

J Cataract Refract Surg. 2005 Mar;31(3):633-5.

Late-onset repetitive traumatic flap folds and partial dehiscence of flap edge after laser in situ keratomileusis.

Miyai T, Miyata K, Nejima R, Shimizu K, Oshima Y, Amano S.

Miyata Eye Hospital, Miyakonojo, Miyazaki, Japan. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

Excerpt:

A 25-year-old woman had traumatic flap folds and partial dehiscence of the flap edge in the right eye 5 and 30 months after laser in situ keratomileusis. The period from injury to treatment was 4 hours and 9 days, respectively. With the first injury, the flap was lifted and stretched with moistened sponges to clear the folds. With the second injury, the folds were hard so the flap was lifted and sutured to stretch the folds.

 Late Traumatic Dislocation of LASIK Flaps  (1)

Indian J Ophthalmol. 2004 Dec;52(4):327-8. Related Articles, Links

Late dislocation of LASIK flap following fingernail injury.

Srinivasan M, Prasad S, Prajna NV.

Aravind Eye Hospital & Postgraduate Institute of Ophthalmology, Madurai, India.

A case of traumatic flap displacement with a fingernail injury four years after LASIK is reported.

Late traumatic dislocation of LASIK flaps  (2)

J Cataract Refract Surg. 2004 Jan;30(1):253-6. Related Articles, Links

Late traumatic dislocation of laser in situ keratomileusis flaps.

Heickell AG, Vesaluoma MH, Tervo TM, Vannas A, Krootila K.

Helsinki University Eye Hospital, Helsinki, Finland.

 

 

Excerpt:

We present 2 patients with late traumatic laser in situ keratomileusis flap dislocation 8 months and 17 months after surgery. One patient had a sharp trauma that caused a partial laceration and the second patient had a blunt trauma that caused a dislocation of the flap. The corneas were examined with slitlamp microscopy, computed corneal topography, and confocal microscopy. One flap was repositioned surgically; the other was treated conservatively with an eye patch.

J Cataract Refract Surg. 2005 Oct;31(10):2016-8. Related Articles, Links

Maldonado MJ, Juberias JR, Pinero DP, Alvarez-Vidal A, Rutzen AR.

From the Department of Ophthalmology (Maldonado, Juberias, Pinero, Alvarez-Vidal), University Clinic, University of Navarra, Pamplona, Spain, and Department of Ophthalmology (Rutzen), University of Maryland, Baltimore, Maryland, USA.

 

 

A flap tear occurred during laser in situ keratomileusis (LASIK) retreatment using a flap-lifting technique in 1 eye of 2 patients 4 to 5 months after the primary procedure. In the first case, the tear occurred in a decentered, standard thickness flap (168 mum) in a location close to the corneal limbus and limbal vessels. In the second case, the tear occurred in a well-centered thin flap (116 mum) that involved a peripheral corneal pannus. The false track was identified early, and central extension of the tear was averted. After the flap was successfully dissected, retreatment was performed without further complications. This report suggests that flaps with margins near the limbus or a corneal pannus may be prone to an earlier and stronger healing process at the edge that may lead to a flap tear during LASIK retreatment. This may be of increasing importance because of the trend toward larger flap diameters.

1: J Refract Surg. 2003 Mar-Apr;19(2):113-23.

Flanagan GW, Binder PS.

Gordon Binder Vision Institute, San Diego, CA, USA.

 

PURPOSE: To determine the factor(s) that influence the dimensions and predictability of the LASIK corneal flap with the Automated Corneal Shaper (ACS) or the Summit Krumeich Barraquer microkeratome (SKBM).

METHODS: We performed a retrospective, comparative interventional case study of 4,428 eyes. Flap dimensions were measured using subtraction ultrasonic pachymetry during LASIK with one of two microkeratomes.

RESULTS: Mean preoperative corneal thickness for all eyes was 555 +/- 35 microm. Corneal curvature and refractive astigmatism were inversely related to preoperative corneal thickness (P<.001). With an attempted flap thickness of 160 microm, the ACS flap thickness averaged 119.8 +/- 22.9 microm; SKBM flaps averaged 160.9 +/- 24.1 microm (P<.001). The coefficient of variation for central pachymetry compared to flap thickness was 6.4% vs. 22.1%. Flap thickness at enhancement was 10 to 17 microm thicker than at primary surgery. An increase in flap thickness was associated with thicker preoperative pachymetry (P<.001) and younger age for both instruments (P<.001) whereas increasing flap thickness was related to flatter preoperative mean keratometry for the ACS (P<.001) and steeper mean keratometry for the SKBM (P=.005). Less preoperative hyperopia or more myopia was related to an increase in flap thickness only for the SKBM (P<.001).

CONCLUSIONS: Flap thickness varies significantly depending on the microkeratome used. Factors that influence flap thickness are primarily corneal thickness, patient age, preoperative keratometry, preoperative refraction including astigmatism, and corneal diameter. By understanding the factors that affect flap thickness, one can select a microkeratome system to allow maximum refractive correction while minimizing the risk of ectasia.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12046880&query_hl=21

 

J Refract Surg. 2002 May-Jun;18(3 Suppl):S347-51.

Shemesh G, Dotan G, Lipshitz I.

Ophthalmic Health Center, Tel Aviv, Israel.

 

PURPOSE: To compare the accuracy and consistency of corneal flap thickness in the right and left eye created by three different widely used microkeratomes during consecutive laser in situ keratomileusis (LASIK).

METHODS: Corneal thickness of 132 eyes of 66 patients was measured preoperatively and intraoperatively. Corneal flap thickness was calculated by subtracting the corneal stromal thickness from the total corneal thickness. Three different microkeratomes were used for creating the corneal flap: Chiron Automated Corneal Shaper (ACS), Baush and Lomb Surgical Hansatome, and Nidek MK 2000 microkeratomes. The same surgeon performed all procedures on the right eye first and then on the left eye using the same blade and the same surgical technique.

RESULTS: Mean corneal flap thickness created by the ACS (160-microm depth setting) microkeratome was 128.30 +/- 12.57 microm in the right eye and 122.96 +/- 13.30 microm in the left eye. The Hansatome (160-microm depth plate) microkeratome created a flap of mean 141.16 +/- 20.11 microm in the right eye and 120.95 +/- 26.95 microm in the left eye, and the Nidek MK 2000 (130-microm depth plate) microkeratome created a flap of 127.25 +/- 4.12 microm in the right eye and 127.54 +/- 3.7 microm in the left eye.

CONCLUSION: Corneal flap thickness tended to be considerably thinner than expected on both eyes using the ACS and Hansatome. With the ACS and Hansatome, the difference in corneal flap thickness between the first and second operated eye was statistically significant. With the Nidek MK 2000 microkeratome, there was no statistically significant difference between the first and second operated eye and measurements were close to desired corneal flap thickness. Intraoperative pachymetry is recommended for every LASIK procedure.

Here is a case report of a woman who developed ectasia following LASIK due to inaccurate flap cut.

The surgery was planned with an estimated flap thickness of 150 um.

From the full-text:

"Subjective optical pachymetry at the slitlamp estimated flap thickness to be approximately 200 um."

J Cataract Refract Surg. 2005 Aug

Reversal of laser in situ keratomileusis-induced ectasia with intraocular pressure reduction.

Hiatt JA, Wachler BS, Grant C.

Boxer Wachler Vision Institute, Beverly Hills, California 90210, USA.

 

A 40 year-old woman had laser in situ keratomileusis for --7.75 --0.75 x 20 in the right eye. Preoperative examinations, including topography, pachymetry, and intraocular pressures (IOPs), were normal, and best spectacle-corrected visual acuity (BSCVA) was 20/20 in each eye. By 4 months postoperatively, the uncorrected visual acuity and BSCVA in the right eye had decreased to 20/40. Corneal topography of that eye was consistent with ectasia. One drop per day of timolol 0.5% (Timoptic XE) was prescribed. Five months postoperatively, the IOP had decreased and BSCVA and topography had improved. At 11 months, BSCVA returned to 20/20 and corneal topography normalized. Topographic difference maps were used to monitor corneal shape changes. In this case, early reduction in IOP completely reversed the ectasia.

The abstract does not reveal that ectasia returned when the patient was taken off pressure-lowering drugs.

http://www.ncbi.nlm.nih.gov/entrez/...t_uids=12502953

 

Cornea. 2003 Jan;22(1):66-9. Related Articles, Links

Tumbocon JA, Paul R, Slomovic A, Rootman DS.

Department of Ophthalmology, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.

 

PURPOSE: To report the occurrence, management, and outcome of late-onset traumatic dehiscence and dislocation of laser in situ keratomileusis (LASIK) flaps.

 

METHODS: Two interventional case reports of patients with late-onset LASIK corneal flap dislocation after ocular trauma occurring at 7 and 26 months after surgery, respectively.

 

RESULTS: The flaps were lifted, stretched, and repositioned after irrigation and scraping of the stromal bed and the underside of the flap. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. The dislocated corneal flaps were successfully repositioned in both cases. The patient whose dislocated flap was repositioned 4 hours after the trauma recovered his uncorrected visual acuity (UCVA) of 20/20 1 week after the procedure and had a well-positioned flap with a clear interface. The patient who was managed 48 hours after the injury required repeat flap repositioning at 10 and 24 days after the initial procedure for treatment of persistent folds and striae in the visual axis. His uncorrected visual acuity 2 weeks after the third flap repositioning was 20/40 + 2. Diffuse lamellar keratitis developed in both patients that resolved with the use of topical corticosteroids.

 

CONCLUSION: Laser in situ keratomileusis corneal flaps are vulnerable to traumatic dehiscence and dislocation, which can occur more than 2 years after the procedure.

J Cataract Refract Surg. 2005 Aug; 31 8 :1664-5.

Nilforoushan MR, Speaker MG, Latkany R.

Laser and Corneal Surgery Associates and New York Eye and Ear Infirmary, New York, New York 10003, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Excerpt:

We present a case of late traumatic flap dislocation 47 months after laser in situ keratomileusis (LASIK). This is the latest reported case of traumatic LASIK flap dislocation to date. The patient was examined 5 days after being struck in the face and found to have a flap dislocation.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12498850&query_hl=1

 

J Cataract Refract Surg. 2002 Dec;28(12):2146-52.

Charman WN.

Department of Optometry and Neuroscience, UMIST, PO Box 88, Manchester M60 1QD, United Kingdom. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

PURPOSE: To calculate theoretically the magnitude of the excess area between the lower surface of the flap and the underlying ablated stroma.

 

METHODS: On the initial assumptions of a nonextensible flap and a spherical cornea, flap and ablated stromal areas were determined as a function of myopic correction in the range of 0 to -12 diopters (D) for typical values of corneal radius (7.8 mm) and flap thickness (160 microm), together with a range of ablation zone diameters (4.0 mm, 6.0 mm, 8.0 mm, and 10.0 mm).

 

RESULTS: Excess flap area increases with the magnitude of the refractive correction and the diameter of the ablated zone. For a -6.0 D correction and an 8.0 mm ablation zone, the excess area is nominally about 1.0 mm(2), giving a potential overlap of the flap at the edge opposite the hinge of about 100 microm.

 

CONCLUSIONS; Excess flap area may cause striae because of wrinkling. Although a nonextensible flap is assumed in the model, any stretching or contraction due to cutting the flap will be independent of the refractive correction. Hence, a mismatch in areas must still occur. This geometric effect may have clinical consequences in optical aberration, refractive regression, or impaired wound healing.

Am J Ophthalmol. 2005 Jun;139(6):1137-9.  

McLeod SD, Mather R, Hwang DG, Margolis TP.  Francis I. Proctor Foundation and the Department of Ophthalmology, University of California-San Francisco, 10 Kirkham Street, San Francisco, CA 94143, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.  

PURPOSE: To report two cases of corneal pathology associated with anterior uveitis after laser in situ keratomileusis (LASIK).  

DESIGN: Observational case report.  

METHODS: A 47-year-old man and a 50-year-old woman who experienced vision loss and corneal changes associated with acute anterior uveitis after LASIK were examined.  

RESULTS: The 47-year-old man, who had undergone LASIK for low myopia developed an interlamellar fluid pocket at the level of the flap interface, whereas the 50-year-old woman, who underwent LASIK for hyperopia, developed marked flap edema without interface fluid collection.  

CONCLUSIONS: These two cases demonstrated acute corneal fluid accumulation associated with episodes of acute anterior uveitis in eyes that had undergone LASIK. Uveitis should be considered a risk factor for vision threatening corneal complications after LASIK.

J Cataract Refract Surg. 2005 May;31(5):922-9.  

Loh RS, Hardten DR.  Minnesota Eye Consultants, Minneapolis, Minnesota, USA.  

PURPOSE: To report persistent unilateral flap edema following laser in situ keratomileusis (LASIK) in patients with asymmetrical central corneal thickness.  

SETTING: Minnesota Eye Consultants, Minneapolis, Minnesota.  

METHODS: Retrospective, noncomparative interventional case series.  

RESULTS: We examined 6 eyes of 3 patients with asymmetrical preoperative pachymetry who developed persistent unilateral flap edema after uneventful myopic LASIK in the eye with thicker preoperative pachymetry. All cases had asymmetrical preoperative pachymetry with flap edema developing in the eye with higher preoperative mean central corneal thickness (CCT) values, preoperative mean CCT subject eye 622 microm (range 556-664 microm) versus fellow eye 583 microm (range 510-621 microm). There was no associated ocular inflammation or rise in intraocular pressure. Significant flap edema resolved on a combination treatment of topical steroid and hypertonic saline.  

CONCLUSIONS: Laser in situ keratomileusis can cause temporary endothelial cell dysfunction or stress, which manifests as temporary flap edema and subclinical corneal thickening. The edema appears to be limited to the actual flap and there was no loss of epithelial integrity in these eyes and no clinically noticeable interface fluid. This new clinical entity appears to occur in patients with asymmetrical preoperative corneal pachymetry and is associated with postoperative specular microscopy abnormalities. In cases with unexplained asymmetrical corneal thickness, preoperative evaluation should include specular microscopy to evaluate for risk features that may increase the chances of a slower postoperative recovery.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=14555904&query_hl=1&itool=pubmed_docsum

Eye Contact Lens. 2003 Oct;29(4):252-4.

Biser SA, Bloom AH, Donnenfeld ED, Perry HD, Solomon R, Doshi S.

Ophthalmic Consultants of Long Island, Rockville Centre, NY, USA.

 

PURPOSE: To report a case of bilateral flap folds after a laser-assisted in situ keratomileusis (LASIK) procedure in which the flap was created by the femtosecond laser.

METHODS: Retrospective chart review.

RESULTS: A 43-year-old white woman underwent bilateral simultaneous LASIK. The corneal flap was created with the femtosecond laser. Postoperatively, the patient noted significantly decreased visual acuity, glare, and haloes. She was diagnosed with corneal flap striae, which were treated unsuccessfully with a lifting and stretching procedure, but responded to subsequent bilateral flap suturing.

CONCLUSIONS: Despite the increased accuracy in flap creation with the femtosecond laser, large flap folds may develop.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15808256&query_hl=19

Ophthalmology. 2005 Apr;112(4):645-9.

Effect of microkeratome suction during LASIK on ocular structures.

Mirshahi A, Kohnen T.

Department of Ophthalmology, Johann Wolfgang Goethe-University,
Frankfurt am Main, Germany.

 

PURPOSE: To study the effect of microkeratome suction on ocular structures during LASIK.

DESIGN: Observational, prospective case series.

PARTICIPANTS: Twenty-one eyes of 11 patients with myopia or astigmatic myopia (8 females, 3 males) were included. The mean patient age was 36.3 years (median, 37 years; range, 24-48 years), and the mean spherical equivalent was -5.03 diopters (D) (median, -4.63 D; range, -2.38 to -8.38 D).

METHODS: We performed preoperative and intraoperative A-scan ultrasonography during application of suction using the Hansatome microkeratome (Bausch & Lomb Surgical, Munich, Germany) to create corneal flaps during LASIK. We also performed preoperative and postoperative B-scan ultrasonography of the posterior ocular segment with special attention to the presence and size of posterior vitreous detachment (PVD).

MAIN OUTCOME MEASURES: We measured changes in the axial length, anterior chamber depth, lens thickness, and vitreous distance (distance from the posterior lens capsule to the posterior pole) during application of the microkeratome suction ring and recorded new occurrences of or increases in the size of the PVD after surgery.

RESULTS: The lens thickness decreased (mean change, -0.20 mm; P = 0.001; 95% confidence interval [CI], -0.11 to -0.30) in 18 eyes during application of the suction ring. The vitreous distance increased (mean change, 0.20 mm; P = 0.004; 95% CI, 0.08-0.32) in 16 eyes. No statistically significant changes were found in the anterior chamber depth (P = 0.75) or axial length (P = 0.51). After surgery, 3 of 14 eyes (21.4%) experienced PVD that did not have echographic signs of PVD before surgery. Of 7 eyes with preoperative PVD, the PVD enlarged in 1 eye (14.3%).

CONCLUSIONS: During application of microkeratome suction, the lens thickness decreases, whereas the vitreous distance increases, suggesting anterior traction on the posterior segment. The relationship between the observed PVD and LASIK merits further investigation.

 

Journal of Refractive Surgery Vol. 24 No. 1 January 2008

Alexander Friedrich Scheuerle, MD; Michael Martin, MD; Hans Eberhard Voelcker, MD; Gerd Auffarth, MD

 

PURPOSE: To report a case of advanced glaucomatous optic atrophy years after bilateral radial keratotomy.

 

METHODS: Multiple intraocular pressure (IOP) measurements of both eyes in a 40-year-old woman who underwent previous bilateral radial keratotomy were obtained using Goldmann applanation tonometry as well as air-puff and Schiotz tonometry. In addition to regular eye examinations, corneal thickness, surface, and shape were examined using Orbscan and C-Scan.

 

RESULTS: The cornea of both eyes did not show signs of corneal thinning, but flattening of the corneal surface was observed. The decreased corneal curvatures precipitated a misjudgment of IOP readings measured by central applanantion tonometry (12 to 18 mmHg), whereas impression and non-contact tonometry revealed elevated IOP values (21 to 27 mmHg).

 

CONCLUSIONS: Changes of the corneal shape without corneal thinning can lead to falsely low IOP values. Therefore, in eyes that have undergone corneal refractive surgery, non-Goldmann measurement of IOP and continued examination of the optic nerve and possibly visual fields are recommended. [J Refract Surg. 2008;24:51-54.]

1: Ophthalmology. 2007 Jul 9; [Epub ahead of print]

Randleman JB, Woodward M, Lynn MJ, Stulting RD.

Department of Ophthalmology, Emory University, Atlanta, Georgia.; Emory Vision, Emory University, Atlanta, Georgia.

 

 

PURPOSE: To analyze the epidemiologic features of ectasia after excimer laser corneal refractive surgery, to identify risk factors for its development, and to devise a screening strategy to minimize its occurrence.

 

DESIGN: Retrospective comparative and case-control study.

 

PARTICIPANTS: All cases of ectasia after excimer laser corneal refractive surgery published in the English language with adequate information available through December 2005, unpublished cases seeking treatment at the authors' institution from 1998 through 2005, and a contemporaneous control group who underwent uneventful LASIK and experienced a normal postoperative course.

 

METHODS: Evaluation of preoperative characteristics, including patient age, gender, spherical equivalent refraction, pachymetry, and topographic patterns; perioperative characteristics, including type of surgery performed, flap thickness, ablation depth, and residual stromal bed (RSB) thickness; and postoperative characteristics including time to onset of ectasia.

 

MAIN OUTCOME MEASURES: Development of postoperative corneal ectasia.

 

RESULTS: There were 171 ectasia cases, including 158 published cases and 13 unpublished cases evaluated at the authors' institution. Ectasia occurred after LASIK in 164 cases (95.9%) and after photorefractive keratectomy (PRK) in 7 cases (4.1%). Compared with controls, more ectasia cases had abnormal preoperative topographies (35.7% vs. 0%; P<1.0x10(-15)), were significantly younger (34.4 vs. 40.0 years; P<1.0x10(-7)), were more myopic (-8.53 vs. -5.09 diopters; P<1.0x10(-7)), had thinner corneas before surgery (521.0 vs. 546.5 mum; P<1.0x10(-7)), and had less RSB thickness (256.3 vs. 317.3 mum; P<1.0x10(-10)). Based on subgroup logistic regression analysis, abnormal topography was the most significant factor that discriminated cases from controls, followed by RSB thickness, age, and preoperative corneal thickness, in that order. A risk factor stratification scale was created, taking all recognized risk factors into account in a weighted fashion. This model had a specificity of 91% and a sensitivity of 96% in this series.

 

CONCLUSIONS: A quantitative method can be used to identify eyes at risk for developing ectasia after LASIK that, if validated, represents a significant improvement over current screening strategies.

 

 

This would suggest  that the 250 RSB rule is NOT safe. Why are they still using it and how are they getting away with it? This is an example of the LASIK industry ignoring medical literature and continuing to do business as usual, keeping the standard of care low and ignoring patients' best interest.

Spherical Aberration and Its Symptoms - Theories on why it occurs and how new technology may address the problem.

Spherical Aberrations - Spherical aberration is one of the most important problems that can occur after laser eye surgery, in particular with high myopic corrections.

Cataract & Refractive Surgery Today

June, 2007

 

http://www.crstoday.com/Pages/News.php

 

According to a paper presented this month at the 6th International Congress on Advanced Surface Ablation and SBK, keratocytes' density decreases substantially in the anterior stroma of  refractive surgery patients during the first postoperative year and remains low for several years.1

William M. Bourne, MD, from the Mayo Clinic College of Medicine in Rochester, Minnesota, performed confocal microscopy on 34 eyes of 23 patients who underwent PRK or LASIK. At 7 years postoperatively, the density of keratocytes in the anterior stroma of PRK patients had dropped from 45,000 to 33,000 cells/mm², a total decrease of approximately 28%. He found a similar decrease (29%) in LASIK patients, whose keratocytes' density dropped from approximately 49,000 cells/mm² preoperatively to approximately 35,000 cells/mm² at 7 years postoperatively.

Because keratocytes secrete the collagen and proteoglycan necessary for the long-term maintenance of corneal clarity and curvature, the loss of these cells after refractive surgery may have long-term consequences for patients' corneal health, said Dr. Bourne. "We feel this possibility is unlikely, but cannot be ruled out," he added.

 

1. Bourne WM. The effect of PRK and LASIK on corneal keratocytes. Paper presented at: The 6th International Congress on Advanced Surface Ablation and SBK; May 5, 2007; Fort Lauderdale, FL.

Klin Monatsbl Augenheilkd. 2007; 224(5):438-40 (ISSN: 0023-2165)

Lautebach S; Funk J; Reinhard T; Pache M

Universitäts-Augenklinik Freiburg. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

BACKGROUND: A steroid-induced glaucoma may develop after bilateral laser in situ keratomileusis (LASIK)  with normal intraocular pressure in applanation tonometry.

 

METHODS: We present the case of a 32-year-old patient who underwent bilateral LASIK for myopia. Postoperatively, a steroid-induced glaucoma developed. After the steroid therapy was stopped applanation tonometry showed normal values. A slight corneal opacity was interpreted as a keratokonjunctivitis sicca because of occupational noxa. One year after LASIK, the patient presented with high intraocular pressure (IOP), maximally excavated optic nerve head and extensive visual fields defect in both eyes.

 

CONCLUSION: Elevated IOP after LASIK can lead to fluid accumulation in the interface. In this case applanation tonometry can underestimate the intraocular pressure. Even when steroid therapy is stopped, the elevated pressure can persist.Steroid glaucoma after laser in situ keratomileusis - A steroid-induced glaucoma may develop after bilateral laser in situ keratomileusis (LASIK)  with normal intraocular pressure in applanation tonometry

Journal of Refractive Surgery Vol. 23 No. 6 June 2007

Sonal S. Tuli, MD; Sandhya Iyer, MD, FRCS

 

 

PURPOSE: To report a case of ectasia occurring >4 years following LASIK with no risk factors and a residual stromal bed >300 µm.

 

METHODS: A 33-year-old woman presented 4 years after LASIK with mild blurring in the left eye. Uncorrected visual acuity (UCVA) had been 20/20 in both eyes previously.

 

RESULTS: Uncorrected visual acuity was 20/20 and 20/40 in the right and left eyes, respectively. Best spectacle-corrected visual acuity (BSCVA) was 20/20 with –0.75 +2.25 X 70° refraction in the left eye, which matched topography. Preoperative corneal thickness was 595 µm, and topography showed no risk factors preoperatively or immediately postoperatively. Calculated residual stromal bed was 342 µm and measured 400 µm with ultrasound microscopy. One year postoperatively, UCVA decreased to 20/400, and BSCVA decreased to 20/60 with refraction of –4.50 +5.00 X 90°. The patient was intolerant of contact lens wear and is considering collagen cross-linking, Intacs, or corneal transplantation.

 

CONCLUSIONS: Ectasia can occur more than 4 years after LASIK. Its etiology is unknown and management is challenging. [J Refract Surg. 2007;23:620-622.]>

 

 

From the full text:

Quote: There was no documentation of intraoperative corneal thickness.

Quote: The posterior float on Orbscan increased to 55 μm (Fig 2). A Paradigm UBM microscope (Paradigm Medical Industries, Salt Lake City, Utah) was used to measure the residual stromal bed directly, which showed flap thickness of 150 μm and residual stromal bed of 400 μm.

Quote: This report shows that ectasia can occur >4 years following uncomplicated LASIK in a patient with no risk factors.

Quote: Confocal microscopy of corneas after LASIK have shown 20% loss of keratocytes above and below the flap interface by apoptosis immediately following surgery, which progressed to 40% at 5 years postoperatively.6 This loss of keratocytes has been seen in histology specimens of corneas removed during keratoplasty for ectasia.7 The decrease in keratocytes could progressively weaken the stromal bed and cause ectasia. It is conceivable that individual corneas differ in stromal keratocytes density, and the loss of keratocytes could cause ectasia in corneas with fewer keratocytes. Although most people develop ectasia much earlier, a weakened stromal bed may explain its development in our patient 4 years after LASIK.

Quote: Management of ectasia after LASIK is challenging due to its rapid progression. The use of contact lenses may correct vision but could be diffi cult to fi t, and patients may be intolerant due to dry eye, as was our patient.

Quote: One third of ectasia cases following LASIK require penetrating keratoplasty. 1 However, penetrating keratoplasty may result in unacceptable lifestyle changes in patients who often choose LASIK due to their active lifestyle. Also, a large graft may be necessary to include the entire LASIK flap and the donor cornea would be sutured to an intact recipient rim, which would increase risk of rejection. Other options are implantation of intrastromal rings (Intacs) and riboflavin with collagen cross-linking.8,9 However, these merely stabilize the cornea, and vision does not improve to the same levels noted before ectasia. In addition, cross-linking involves ultraviolet light, and its long-term effects are unknown.

Invest Ophthalmol Vis Sci. 2007 Jun;48(6):2570-5.

Rodriguez AE, Rodriguez-Prats JL, Hamdi IM, Galal A, Awadalla M, Alio JL.Vissum-Instituto Oftalmologico de Alicante, Alicante, Spain;

 

 

PURPOSE: To study the effect of the LASIK procedure performed with a femtosecond laser and a manual microkeratome on the conjunctival goblet cell and epithelial cell populations.

 

METHODS: In this prospective, nonrandomized, masked study, 64 eyes undergoing LASIK were included: 30 with the Moria M2 (M2) microkeratome and 34 with the IntraLase femtosecond laser (IL). The preoperative spherical equivalent was -2.0 +/- 3.8 D in the M2 group and -3.1+/- 3.1 D in the IL group. The time that the suction ring was applied on the eye was registered, and goblet cell density (GCD), epithelial cell morphology, and inflammatory cells were evaluated by conjunctival impression cytology, before and after the surgery.

 

RESULTS: All the patients in both groups showed a decrease in GCD after LASIK (P < 0.001) that recovered after 6 months. At 1 week, 1 month, and 3 months, GCD was lower with IL than with M2 (P < 0.019, P < 0.001, and P < 0.024, respectively). The mean period that the suction ring was applied was longer in the IL than in the M2 group (P < 0.001). There was a high correlation between the decrease in GCD and the suction time (R = 0., and the preoperative spherical equivalent (R congruent with 0.4).

 

CONCLUSIONS: Impression cytology showed a greater reduction in goblet cell populations after IL than after M2, probably because of the length of time that the suction ring exerted pressure on the conjunctiva. These changes in the goblet cells may contribute to the development of the ocular surface syndrome after LASIK procedures.

vs Hansatome microkeratome

 

J Refract Surg. 2007 Mar;23(3):305-7.

Ramirez M, Hernandez-Quintela E, Naranjo-Tackman R. Cornea and Refractive Surgery Services, Asociacion Para Evitar la Ceguera en Mexico, Hospital Luis Sanchez Bulnes, Universidad Nacional Autonoma de Mexico, Mexico City, Mexico. This email address is being protected from spambots. You need JavaScript enabled to view it.

 

 

PURPOSE: To evaluate and compare confocal microscopy findings between a femtosecond laser and a mechanical microkeratome.

 

METHODS: Eighteen eyes of nine patients underwent LASIK. Corneal flaps were created with the femtosecond laser in the right eyes and a mechanical microkeratome in the left eyes. The corneal flap interface was analyzed in all eyes with a confocal microscope at 1 week and 1 month postoperatively.

 

RESULTS: All eyes showed small reflective particles at the corneal flap interface. The mean number of reflective particles was not statistically significantly different at 1 week (P = .078) and 1 month (P = .2 using a femtosecond laser and a mechanical microkeratome.

 

CONCLUSIONS: Confocal microscopy findings at the corneal flap interface showed a similar number of particles using both systems.

JOURNAL OF REFRACTIVE SURGERY 2007; 23(4):338

By Ilpo S. Tuisku, MD; Nina Lindbohm, MD, PhD; Steven E. Wilson, MD, PhD; Tim M. Tervo, MD, PhD

 

 

PURPOSE: To assess subjective symptoms and objective clinical signs of dry eye and investigate corneal sensitivity after high myopic LASIK.

 

METHODS: Twenty eyes of 20 patients with a mean age of 34±7.5 years who had undergone high myopic LASIK 2 to 5 years previously and 10 eyes of 10 controls with a mean age of 39.8±10.4 years were enrolled in the study. Clinical signs of dry eye and subjective dry eye symptoms were determined. The corneal sensitivity was assessed using non-contact esthesiometer.

 

RESULTS: The preoperative spherical equivalent refraction was –11.40±1.40 diopters (D) (range: –9.10 to –14.00 D) and the intended spherical equivalent refraction correction was –10.40±1.10 D (range: –8.30 to –12.50 D). Schirmer’s test score was 14.4±8.9 mm in patients and 9.0±4.2 mm in controls (P=.066). The break-up time was 15.9±11.2 seconds in patients and 14.0±10.0 seconds in controls (P=.505). The mean corneal sensitivity was 73.5±29.6 mL/min in patients and 78.0±18.7 mL/min in controls (P=.666). The majority (55%) of patients still reported dry eye symptoms. Ocular surface disease index indicating degree of dry eye symptoms was significantly higher in LASIK patients (18.6±13.4%) compared to controls (7.5±5.7%; P=.022).

 

CONCLUSIONS: The majority of patients who received LASIK for high myopia reported ongoing dry eye symptoms, although objective clinical signs of tear insufficiency and hypoesthesia were not demonstrable. We assume that symptoms represent a form of corneal neuropathy rather than dry eye syndrome. [J Refract Surg. 2007;23:338-342.]

Potential new post-laser refractive surgery complication identified

 

 

A new syndrome characterized by noninflammatory corneal opacification can occur in some patients within 9 days after undergoing LASIK or PRK, according to a study. The opacification gradually clears over several months and can also cause a possible hyperopic shift in refraction, the study authors said.

Baris Sonmez, MD, and Robert K. Maloney, MD, identified 23 eyes of 14 patients with the syndrome, which they termed central toxic keratopathy. Four eyes had undergone PRK and 19 eyes had undergone LASIK.

In all cases, eyes developed central corneal opacification in the laser-treated area 3 to 9 days after surgery, which persisted for 2 to 18 months, the authors reported. Eighteen of the 19 LASIK-treated eyes developed diffuse lamellar keratitis before the onset of the opacification, they noted.

Nine eyes also developed hyperopia over 2 D, one eye lost two lines of best corrected visual acuity, and two eyes lost one line, according to the study The hyperopia and residual striae can be treated with an enhancement procedure, but topical or oral corticosteroid treatment is not indicated, the authors noted.

The cause of the keratopathy is not known, they added.

The study is published in the March (2007) issue of the American Journal of Ophthalmology.

JOURNAL OF REFRACTIVE SURGERY 2007; 23(3):312

By Farid Karimian, MD; Alireza Baradaran-Rafii, MD; Mohammad Ali Javadi, MD; Roshanak Nazari, MD; Hossein Mohammad Rabei, MD; Mohammad- Reza Jafarinasab, MD

 

 

PURPOSE: To report clinical manifestations and the bacteriologic profiles of three patients with bilateral bacterial keratitis following photorefractive keratectomy (PRK).

 

METHODS: Photorefractive keratectomy was performed for mild to moderate myopia or compound myopic astigmatism. Bandage contact lenses were fitted at the conclusion of each surgery. Bilateral infectious keratitis was diagnosed within 3 days after surgery. Smear and culture were obtained in all three cases. Patients were treated with topical fortified antibiotics (cefazolin and gentamicin).

 

RESULTS: All patients presented with severe bilateral ocular pain, photophobia, purulent discharge, and dense corneal infiltration. Causative organisms were Staphylococcus aureus (n=2) and Streptococcus pneumoniae (n=1). Ulcers were controlled with aggressive medical therapy in five eyes; however, tectonic penetrating keratoplasty was required in one eye.

 

CONCLUSIONS: Uncontrolled blepharitis and bandage contact lens use appears to play a role in the development of bacterial keratitis after PRK. Avoidance of simultaneous bilateral surgery in patients with risk factors for bacterial keratitis, preoperative control of blepharitis, and good contact lens hygiene is suggested. [J Refract Surg. 2007;23:312-315.]

JOURNAL OF REFRACTIVE SURGERY 2007; 23(3):309

By Prashant Garg, MS; Savitri Sharma, MD; Geeta K. Vemuganti, MD; Balasubramanya Ramamurthy, MD

 

 

PURPOSE: To report a cluster of Nocardia asteroides keratitis cases after LASIK.

 

METHODS: Retrospective review of the history and examination of three patients (four eyes) operated on the same day at a single center who developed postoperative keratitis. All patients underwent lifting of the superficial flap for microbiologic evaluation of the corneal scrapings. The operating surgeon was contacted to identify the possible source of contamination.

 

RESULTS: Two patients underwent simultaneous bilateral LASIK; however, only one developed postoperative keratitis in both eyes. One patient had unilateral surgery and developed keratitis in the operated eye. Microscopic examination of smears from all eyes revealed thin, branching, acid-fast, filamentous bacteria that were identified as Nocardia asteroides after culture. The infiltrates resolved with topical administration of amikacin sulphate (2.5%) and topical and oral trimethoprim-sulfamethoxazole. Final visual acuity ranged between 20/25 and 20/80. The operating surgeon had used the same blade and microkeratome in all patients.

 

CONCLUSIONS: Nocardia, a relatively unusual organism, can cause an epidemic of infection after LASIK. [J Refract Surg. 2007;23:309-312.]

Due to Steroid-induced Elevation of Intraocular Pressure

 

JOURNAL OF REFRACTIVE SURGERY 2007; 23(3):244

By Joseph Frucht-Pery, MD; David Landau, MD; Frederik Raiskup, MD; Fiek Orucov, MD; Eyal Strassman, MD; Eytan Z. Blumenthal, MD; Abraham Solomon, MD

 

 

PURPOSE: To report the clinical course of early transient reduction of uncorrected visual acuity (UCVA) after LASIK surgery resulting from steroid-induced elevation of intraocular pressure (IOP).

 

METHODS: Twenty-nine eyes of 15 patients who received topical corticosteroids after uneventful myopic LASIK surgery and had a decrease in UCVA within the first 3 weeks were evaluated retrospectively.

 

RESULTS: Intraocular pressure increased by 4 to 30 mmHg from preoperative to postoperative days 4 to 20. Twenty-seven of 29 eyes had a decrease in UCVA and/or best spectacle-corrected visual acuity (BSCVA). All eyes, except one, had edema without evidence of inflammation in the interface or the remainder of the cornea. Discontinuation of topical corticosteroids and application of anti-glaucoma medications resulted in a decrease of IOP to normal levels, reduction or disappearance of the edema, and recovery of BSCVA.

 

CONCLUSIONS: Early onset steroid-induced elevation of IOP after LASIK may cause corneal edema and a sudden decrease in UCVA. Rapid diagnosis and treatment can control IOP and recover the visual loss. [J Refract
Surg. 2007;23:244-251.]

J Cataract Refract Surg. 2006 Dec;32(12):2075-2079.

Munoz G, Albarran-Diego C, Sakla HF, Javaloy J, Alio JL.

From the Refractive Surgery Department Centro de Especialidades Marques de Sotelo and Hospital NISA Virgen del Consuelo (Munoz, Albarran-Diego), Valencia, and the Refractive Surgery Department (Munoz, Sakla, Javaloy, Alio), VISSUM Instituto Oftalmologico de Alicante, Alicante, Spain.

 

 

PURPOSE: To describe the incidence of transient light-sensitivity syndrome (TLSS) after laser in situ keratomileusis (LASIK) with the femtosecond laser and to identify preventive strategies.

 

SETTING: Hospital NISA Virgen del Consuelo, Valencia, Spain.

 

METHODS: The first 765 eyes operated on with the 15 KHz femtosecond laser were prospectively analyzed for subjective complaints and clinical findings compatible with TLSS. Intraoperative settings, postoperative treatment, and development of complications were analyzed.

 

RESULTS: Overall, TLSS developed in 10 eyes (incidence 1.3%). However, the incidence decreased from 2.8% to 0.4% when aggressive topical steroids were used during the first 3 postoperative days. Postoperative interface inflammation and postoperative use of a low-dose topical steroid regimen were associated with a higher incidence of TLSS.

 

CONCLUSIONS: Transient light-sensitivity syndrome is a relatively uncommon complication related to the use of the femtosecond laser. Postoperative interface inflammation may increase the probability of developing TLSS, whereas an aggressive postoperative steroid regimen seemed to provide protection against it.

AJO, Vol 129, Issue 5 (May 2000) Pages 668-671

D. Matthew Bushley aA This email address is being protected from spambots. You need JavaScript enabled to view it., Vernon C. Parmley a and Patrick Paglen bet al.

 

 

PURPOSE: To report a case of visual field defect associated with laser in situ keratomileusis.

 

METHODS: Case report. A 28-year-old woman with high myopia (-10D) and a family history of normal tension glaucoma underwent bilateral laser in situ keratomileusis keratorefractive surgery. Preoperatively, both eyes had normal intraocular pressure and visual field.

 

RESULTS: At the first postoperative visit 1 day after apparently uncomplicated laser in situ keratomileusis, the patient reported a scotoma in the right eye. At 3-month follow-up, visual fields revealed the patient had developed a near-superior altitudinal visual field defect in the right eye. The defect did not progress over 1 year of follow-up examinations.

 

CONCLUSION: Increased intraocular pressure associated with the microkeratome vacuum ring used during laser in situ keratomileusis may have precipitated optic nerve head ischemia and visual field defect.

...in eyes requiring cataract surgery: BESSt formula

 

J Cataract Refract Surg. 2006 Dec;32(12):2004-14.

Borasio E, Stevens J, Smith GT.

From the Moorfields Eye Hospital, London, United Kingdom.

 

 

PURPOSE: To describe a new formula, BESSt, to estimate true corneal power after keratorefractive surgery in eyes requiring cataract surgery.

 

SETTING: Moorfields Eye Hospital, London, United Kingdom.

 

METHODS: The BESSt formula, based on the Gaussian optics formula, was developed using data from 143 eyes that had keratorefractive surgery. The formula takes into account anterior and posterior corneal radii and pachymetry (Pentacam, Oculus) and does not require pre-keratorefractive surgery information. A software program was developed (BESSt Corneal Power Calculator), and corneal power was calculated in 13 eyes that had keratorefractive surgery and required cataract surgery.

 

RESULTS: In the eyes having phacoemulsification, target refractions calculated with the BESSt formula were statistically significantly closer to the postoperative manifest refraction (mean deviation 0.08 diopters [D] +/- 0.62 [SD]) than those calculated with other methods as follows: history technique (-0.07 +/- 1.92 D; P = .05); history technique with double-K adjustment (0.13 +/- 2.39 D; P = .05); Holladay 2 with K-values estimated with the contact lens method (-0.76 +/- 1.36 D; P = .03); Holladay 2 with K-values from Atlas topographer (Humphrey) (-0.55 +/- 0.61 D; P<.01). Using the BESSt formula, 46% of eyes were within +/-0.50 D of the intended refraction and 100% were within +/-1.00 D.

 

CONCLUSIONS: The BESSt formula was statistically significantly more accurate than the other techniques tested. Thus, it could significantly improve intraocular lens power calculation accuracy after keratorefractive surgery, especially when pre-refractive surgery data are unavailable.

Trans Am Ophthalmol Soc. 2005;103:56-66; discussion 67-8.

Erie JC, McLaren JW, Hodge DO, Bourne WM.

Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.

 

 

PURPOSE: To measure changes in keratocyte density up to 5 years after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).

 

METHODS: This was a prospective, nonrandomized clinical trial. Eighteen eyes of 12 patients received PRK to correct a mean refractive error of -3.73 +/- 1.30 D, and 17 eyes of 11 patients received LASIK to correct a mean refractive error of -6.56 +/- 2.44 D. Corneas were examined by using confocal microscopy before and 6 months, 1 year, 2 years, 3 years, and 5 years after the procedures. Keratocyte densities were determined in five stromal layers in PRK patients and in six stromal layers in LASIK patients. Differences between preoperative and postoperative cell densities were compared by using Bonferroni-adjusted paired t tests.

 

RESULTS: After PRK, keratocyte density in the anterior stroma was decreased by 39%, 42%, 45%, and 47% at 6 months, 2 years, 3 years, and 5 years, respectively (P < .001). At 5 years, keratocyte density was decreased by 20% to 24% in the posterior stroma (P < .05). After LASIK, keratocyte density in the stromal flap was decreased by 22% at 6 months (P < .02) and 37% at 5 years (P < .005). Keratocyte density in the anterior retroablation zone was decreased 18% (P < .005) at 1 year and 43% (P < .005) at 5 years. At 5 years, keratocyte density was decreased by 19% to 22% (P < .05) in the posterior stroma.

 

CONCLUSIONS: Keratocyte density is decreased in the anterior stroma after PRK and in the stromal flap and the retroablation zone after LASIK for up to 5 years. Posterior stromal keratocyte deficits are first noted at 5 years.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15502488&dopt=Abstract

 

PURPOSE: To report a patient with a past history of LASIK who had decreased vision and induced corneal steepening after lower eyelid ptosis. Surgical correction of lower eyelid ptosis decreased the corneal steepening and improved visual acuity.

 

METHODS: Interventional case report. RESULTS: A 37-year-old woman had a history of bilateral LASIK, childhood strabismus surgery, and multiple surgeries to release scarring and improve motility in her left eye. Last surgery to release scar tissue resulted in reverse ptosis (lower eyelid ptosis) and decreased visual acuity from induced corneal steepening. Correction of lower eyelid ptosis by reinsertion of the retractor complex resulted in decreasing corneal steepening, improved visual acuity, and good anatomic position of the lower eyelid.

 

CONCLUSION: Lower eyelid ptosis may induce corneal steepening and decreased vision after LASIK.

 

 

Surgical correction of ptosis can decrease the extent of steepening and improve visual acuity.

 

 

Cataract Refract Surg. 2002 Mar;28(3):407-16.

 

Huang D, Arif M.

 

Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA. 

 

 

PURPOSE: To investigate the effect of laser spot size on the outcome of aberration correction with scanning laser corneal ablation.

 

SETTING: Cleveland Clinic Foundation, Cleveland, Ohio, USA.

 

METHODS: Corrections of wavefront aberrations of Zernike modes from the second to eighth order were simulated. Gaussian and top-hat beams of 0.6 to 2.0 mm full-width-half-maximum diameters were modeled. The fractional correction and secondary aberration (distortion) were evaluated.

 

RESULTS: Using a distortion/correction ratio of less than 0.5 as a cutoff for adequate performance, a 2.0 mm or smaller beam was adequate for spherocylindrical correction (Zernike second order), a 1.0 mm or smaller beam was adequate for correction of up to fourth-order Zernike modes, and a 0.6 mm or smaller beam was adequate for correction of up to sixth-order Zernike modes.

 

 

CONCLUSIONS: Since ocular aberrations above the Zernike fourth order are relatively insignificant in normal eyes, current scanning lasers with a beam diameter of 1.0 mm or less are theoretically capable of eliminating most higher-order aberrations.

Following Wavefront-guided and Conventional LASIK Surgery

 

http://www.journalofrefractivesurgery.com/showAbst.asp?thing=13579

 

Journal of Refractive Surgery  Vol. 22   No. 7   

September 2006 

 

Hyung Keun Lee, MD; Chul Myung Choe, MD; Kyoung Tak Ma, MD; Eung Kweon Kim, MD, PhD

 

 

PURPOSE: To compare contrast and glare vision in a prospective study of eyes treated using conventional and wavefront-guided LASIK surgery. The reproducibility of a glaremeter device used to quantitatively measure glare and halo was also determined.

 

METHODS: Ninety-two eyes of 46 patients underwent conventional LASIK surgery and 104 eyes of 52 patients underwent wavefront-guided LASIK surgery. Visual acuity, glare disability measured using a glaremeter, and contrast sensitivity assessed using a Pelli-Robson chart were measured monthly for 6 months postoperatively. Glaremeter testing was performed under both mesopic (5.4±0.4 cd/m2) and photopic (78.3±4.4 cd/m2) conditions. To evaluate the reproducibility of the glaremeter, 36 eyes of 18 nonoperated myopic patients were tested.

 

RESULTS: The coefficient of variation and the reliability coefficient for the glare test were 13.6% and 95.2%, respectively. The glaremeter showed that glare disability under mesopic conditions differed between conventional and wavefront-guided LASIK eyes over 6-month follow-up (907.5±491.5 vs 986.1±448.0 pixels preoperatively and 1717.1±521.2 vs 1407.8±411.3 pixels at 6 months, P<.0001). At 6 months, contrast sensitivity log values were 1.62±0.31 and 1.78±0.34 for conventional and wavefront-guided LASIK eyes, respectively (P=.010). The visual complaint score was lower in the wavefront-guided LASIK group (P=.0116).

 

CONCLUSIONS: Compared to conventional ablation, wavefront-guided ablation provided superior outcomes in terms of postoperative glare under mesopic conditions, subjective complaints, and contrast sensitivity. In addition, it appears the glaremeter can be used for clinical quantitative evaluation of glare and halo. [J Refract Surg. 2006;22:647-655.]

 

http://www.eyeworld.org/article.php?sid=2267

by Matt Young EyeWorld Staff Writer


The debate is growing with one laser squarely in the center.

Satisfied users of Alcon Inc.’s LADARVision excimer laser abound, but other surgeons are convinced retreatments were too frequent after they used the system.
LADARVision detractors cite a study published in the April 2003 edition of Ophthalmology as evidence that they’re right. The study, authored by Peter Hersh, M.D., an Alcon (Forth Worth, Texas) consultant concluded that “patients treated on the LADARVision laser had almost twice the rate of retreatment (18.2%) compared with the Summit Apex Plus laser (9.7%),” which is no longer manufactured.


Still, Dr. Hersh and others said that retreatment rates alone are so variable and so surgeon- and patient-dependent that it is unwise to lay blame on the LADARVision.


“There are hundreds of doctors around the world who use the LADARVision system and the vast majority of them are extremely satisfied with its performance,” said Doug MacHatton, Alcon's vice president of investor relations and strategic corporate communications. “Numerous peer-reviewed articles, as well as independent surveys of refractive lasers confirm that the LADARVision delivers excellent patient outcomes and that its enhancement rate is similar to other laser systems.”

Alcon headquarters in
Fort Worth, Texas. Source: Alcon

Mr. MacHatton noted that retreatment rates reported out of LADARVision's Food and Drug Administration (FDA) clinical trials range from 3% to 10%.
As for the 18.2% LADARVision retreatment rate that was published in Ophthalmology, Mr. MacHatton said, “Dr. Hersh’s analysis of the causes of enhancements are clearly supportive of Alcon’s position that retreatment rates or secondary procedures are primarily the result of variable patient healing, initial refractive error and complexity, practice of medicine decisions, and the many variables in any laser refractive procedure.” He also said the laser used in Dr. Hersh’s study was an earlier version of LADARVision before the upgrade to the company’s current LADARVision 4000.

Some surgeons—Mr. MacHatton and others note—retreat 20/20 eyes for higher patient satisfaction. Steven C. Schallhorn, M.D., director of cornea services,
Naval Medical Center, San Diego, who has analyzed LADARVision surgery for numerous studies, and Richard J. Mackool, M.D., Astoria, N.Y., an Alcon consultant who uses LADARVision extensively, noticed no problems with retreatments after using the excimer laser.


Others note that because LADARVision has the widest range of any laser, it is used for more extreme, difficult patient populations.
“Our retreatment rates are extremely low, and almost nonexistent, since we’ve gone to CustomCornea,” said Dr. Mackool, director, Mackool Eye Institute.

CustomCornea is Alcon’s wavefront-guided laser procedure using LADARVision.

While Dr. Mackool said his retreatment rates are actually less than the normal 8% to 10% range, “there may be a lot of people out there who have higher retreatment rates because they tackle more extreme refractive errors,” he said.

However, not everyone agrees.

Surgeons voice concerns

Sam Omar, M.D., medical director, Advanced Vision Institute,
Longwood, Fla., said after he did about 40 cases with LADARVision between 2000 and 2001, he stopped using the machine due to both a high retreatment rate and poor outcomes. He estimated that he enhanced about 20% of his LADARVision patients.

Source: Mackool Eye InstituteIn order to fix the problem, Dr. Omar said he modified his nomogram three times and worked with Alcon staff, but the problem remained unresolved.


“LADARVision at times would be spectacular,” Dr. Omar said. “Other times, the result would be a failure. You'll program in a +4 treatment on a patient who was +3 because you're making your nomogram adjustment, and after a month or two the patient would be +2.”
Other ophthalmologists also voiced serious concerns about LADARVision.


“While none of the multiple laser platforms I have used since 1996 is perfect, my experience with LADARVision was particularly troubling,” said Roy S. Rubinfeld, M.D., of Washington Eye Physicians & Surgeons, Chevy Chase, M.D. “I had several occasions where the thing would just stop working,” said Rubinfeld, who claimed his retreatment rate was at least 25% for two LADARVision machines used to perform a total of more than 1,000 cases from 2000 to 2002.

“I had one time where I had to put the flap back with a flashlight because the illumination light went off so I couldn’t figure out where the flap was,” Dr. Rubinfeld said. Undercorrections, overcorrections, astigmatism, and regression after LADARVision often prompted his retreatments, Dr. Rubinfeld said.

Study author defends LADARVision

While the retreatment rate associated with LADARVision was almost double that of the Summit Apex Plus in the study, Dr. Hersh concluded that “the difficulty of the initial procedures performed on the LADARVision laser, for example, higher degrees of astigmatism correction or mixed astigmatic corrections, compared with the Apex Plus laser, where more spherical myopic corrections were treated, may partially account for these findings.”

Furthermore, Dr. Hersh concluded that because the LADARVision was the newer machine in his practice, patient expectations could have been greater with the platform, causing more desire for enhancement. Later, during an e-mail exchange, Dr. Hersh said: “We did not at all concentrate on or design our methodology based on the difference between lasers. Thus, this is the wrong study from which to draw any conclusions regarding differences in retreatment rates between different systems.”


But other data—while not precise—suggest that retreatments after LADARVision can occur with abnormal frequency.

Data show high retreatment numbers

According to data presented under oath in a deposition, 27
U.S. surgical sites enhanced 20% or more primary LADARVision treatments from 2000 to 2002. That percentage is based on the ratio of all retreatments to all primary treatments recorded during that time frame. In 2002 alone, the data indicate that 55 sites had enhancement rates of 20% or greater, although sources familiar with the data noted that the enhancement rates could be somewhat off (either larger or smaller) depending upon whether some retreatments occurred at sites other than the original, occurred after primary treatments in previous years, or for other reasons.


In particular, AAPECS Eye Care (Virginia Beach, Va.) had retreatment rates of 17.8% in 2000, 18.1% in 2001, and 32.6% in 2002, according to the data.

“Before they came out with CustomCornea, I had significant retreatment rates,” said Ronald B. Frenkel, M.D., owner of AAPECS Eye Care. “But I’m a little bit different than most other people in that I would retreat a 20/20 eye. If someone came to me and they were unhappy with their vision and I could make it better, I did. But I still think my results were not as good as they should have been.”
He also questioned the 2002 retreatment rate listed for his clinic, noting that he has done many retreatments on patients whose primary treatments occurred in previous years.


“I still do probably two retreatments every two weeks, but none of them are on patients that I’ve done within the past year,” Dr. Frenkel said.
In fact, with CustomCornea, Dr. Frenkel said he has only retreated one patient.

Nine TLC Laser Eye Centers had LADARVision enhancement rates of 20% or greater in 2002, the data showed. A spokeswoman for TLC Laser Eye Centers, which she said has 70 clinics nationwide and uses LADARVision, said the company is not aware of any problems with the system's retreatment rates.
Alcon officials acknowledged that the data appear to be based on a document their company prepared in 2002 to summarize the number of primary and secondary procedures billed to customers. The officials contend that the document cannot be used to assess a laser's performance.

“In order to properly determine enhancement ratios for any laser or practice, it is necessary to know when the primary procedure was done, whether it was done on a different laser or by another doctor,” Mr. MacHatton wrote to EyeWorld. “In addition, comprehensive clinical data is needed on the pre- and post-operative assessment of patient populations. This would include the composition of high myopes, hyperopes, and patients with high levels of astigmatism or mixed astigmatism, the post-operative surgical results compared to the targeted ablation, and the enhancement philosophy of each physician.”

Source: Mackool Eye Institute“The referenced data….does not contain or rely on any of this information, so using it to analyze enhancements is completely invalid,” Mr. MacHatton wrote to EyeWorld.

Access to retreatment data

Alcon receives primary and secondary procedure data from all LADARVision 4000 machines for billing purposes, but surgeons contend it is not something they can readily retrieve from Alcon.


“Alcon refused to supply their billing information showing retreatment rates on our LADARVision laser after I requested that they do so,” said R. Doyle Stulting, M.D., Ph.D., professor of ophthalmology,
Emory University, Atlanta.

Officials at Alcon said the information is readily available to individual surgeons.

Alcon officials told EyeWorld that the information could not be used for clinical analysis because it is incomplete without surgical site data. They said they do send clinical teams to surgical sites if ophthalmologists suspect a problem with LADARVision.


A lawsuit, filed on behalf of EBW Laser Inc. (
Greensboro, N.C.) against Alcon in North Carolina, contends that underlying problems with LADARVision were intentionally concealed by Alcon. That lawsuit alleges that two LADARVision machines “suffered from unpredictable and erratic problems apparently caused by poor maintenance and repairs but aggravated by a design flaw in the machines that rendered the doctors using the machines unable to test their accuracy other than relying upon the machine’s own reports.” One system caused a retreatment rate of more than 50%, the lawsuit contends.

In an August letter to physicians, Bill Barton, vice president and general manager of Alcon’s surgical division, referred to the lawsuit allegations as “invalid contentions of parties who are attempting to avoid payment of multi-million dollar debts owed to Alcon.”

Meanwhile, the FDA has contacted at least one surgeon to request information about the performance of the LADARVision.

Everette Beers, Ph.D., the FDA’s chief of the diagnostic and surgical devices branch in the division of ophthalmic and ENT devices, declined to comment whether there is an investigation into LADARVision. While medical equipment manufacturers must report to the FDA any adverse effects that happen with unexpected severity or frequency, Dr. Beers said as long as patients don’t lose best corrected visual acuity, the FDA doesn’t necessarily consider retreatments adverse events.


Alcon officials said the company has not reported a high incidence of retreatments with any LADARVision system to the FDA because it hasn’t needed to do so.

“We haven’t identified any systemic issues that exist with the LADARVision 4000,” Mr. MacHatton said.

LADARVision was recalled twice in 2000 and 2001, and in many instances the same machines were recalled, according to two FDA enforcement reports. The reason for the 2000 recall, which applied to 136 units, was that patients had an “unsatisfactory vision correction due to error in ablation mask function.” The explanation for the 2001 recall, which affected 85 units, was that “unanticipated laser pulses reaching the cornea will cause ablation of the corneal surface, which could result in a central corneal defect of about 1 mm in diameter.”


Alcon officials note that no patients were injured on machines affected by the recalls.

Mixed views on retreatment

Whether or not higher retreatment rates have occurred because of an inherent LADARVision glitch, Alcon officials maintain retreatments generally are minor occurrences.


Similarly, Dr. Schallhorn doesn’t think retreatments are serious problems.


“Any time you have to lift the flap there’s a slight risk,” Dr. Schallhorn said. “I wouldn’t put it into a high-risk category.”
In his Ophthalmology study, Dr. Hersh mentioned that retreatments often do or don’t occur depending on patient’s subjective interpretation of what is visually satisfactory, reminding readers that “patient satisfaction, not emmetropia per se, is the essential goal of any refractive surgery procedure.”
Further confounding the issue of retreatment, Dr. Hersh said, is its definition. Some scientific literature even considers treating diffuse lamellar keratitis after LASIK a retreatment, he said.


Dr. Rubinfeld said he doesn’t consider retreatments just “touch-ups.”


“Additional risks occur with every surgical treatment and patients don’t want to be enhanced,” he said. “Whatever you can do to make your enhancement rate lower is good. You owe it to your patients.” 

Editors’ note: Drs. Omar, Schallhorn, Frenkel, Stulting and Rubinfeld have no financial interests related to their comments. Drs. Mackool and Hersh are consultants for Alcon.

Contact Information
Beers: 301-594-2018 ext 136, fax 301-827-4601, This email address is being protected from spambots. You need JavaScript enabled to view it.
Frenkel: 757-552-0800, fax 757-497-5900, This email address is being protected from spambots. You need JavaScript enabled to view it.
Hersh: 917-225-8965, 201-692-9646, This email address is being protected from spambots. You need JavaScript enabled to view it.
MacHatton: 817-551-8974, This email address is being protected from spambots. You need JavaScript enabled to view it.
Mackool: 718-728-3400, fax 718-728-4882, This email address is being protected from spambots. You need JavaScript enabled to view it.
Omar: 407-389-0800, fax 407-650-3400, This email address is being protected from spambots. You need JavaScript enabled to view it.
Rubinfeld: 301-654-5114, 301-654-9132, This email address is being protected from spambots. You need JavaScript enabled to view it.
Schallhorn: 619-532-6702, fax 619-532-7272, This email address is being protected from spambots. You need JavaScript enabled to view it.
Stulting: 404-778-6166, This email address is being protected from spambots. You need JavaScript enabled to view it.

http://www.ophthalmic.hyperguides.com/default.asp?secti.../refractive/list.asp

Dan Z. Reinstein, MD, MA(Cantab), FRCSC, DABO

EXCERPTS:

Introduction

What differentiates the cornea from materials such as a contact lens? The cornea is an elastic collagen lamellar structure, the curvature of which is maintained firmly and constant by IOP. It is not difficult to imagine that differential thinning of the stroma can lead to differential bowing of the corneal layer producing central bulging.1 Additionally, the lamellar packing can be altered by the creation of a flap and tissue removal-the peripheral corneal lamellae adjacent to the keratectomized layer are no longer held tense and can relax, thus potentially causing a pull on the central cornea and causing central flattening.2 Finally, the epithelial thickness profile determines the majority of the final refractive power of the cornea, so changes in the profile of the epithelial layer can also cause changes in refraction.3

"Regression is reversion to an earlier condition or state." To illustrate this, imagine a myopic eye, undergoing LASIK for -4 D, that was found to be plano on postoperative day 1, -0.25 to 0.25x180 at 1 month, -0.75 at 3 months, 6 months, and 1 year. In this case, there was an initial correction of -4 D, which "regressed" to -0.75 D where it stabilized. Why did this case regress? Is it because the epithelium thickened in the center? Is it because the flap was too thick, and there was bowing of the central cornea forward?

For the purposes of this article, regression is defined narrowly to the observation of a shift in refraction postoperatively that tends to reverse the intended effect. The author is, therefore, excluding the situation where the refraction does not stabilize and continues to change due to plastic deformity of the cornea-a process known as keratectasia.4, 5 Differences among regression, primary undercorrection, and ectasia will now be illustrated.

If an eye was treated by LASIK for -8 D and on day 1, through to 1 week, 3 months, 6 months, and 1 year, the eye was found to be stable at -1 D, this would be defined as a primary undercorrection, rather than regression. If this same eye had been -0.75 D at postoperative day 1, -1.50 D at 1 month, -1.75 D at 3 months, but then stable through to 1 year, then the eye would have been said to have had a primary undercorrection of -0.75 D followed by regression from -0.75 to -1.75 D. It is important to differentiate between the causes of undercorrection because they point to the possible etiology and how to avoid keratectasia.

Primary undercorrection has many etiologies, but these can be divided into corneal and non-corneal causes. Non-corneal causes will include inaccurate preoperative refraction, inadequate laser energy delivery (eg, excess bed hydration, room humidity, inappropriate laser energy calibration, laser head energy instability). Corneal causes essentially include cases where the biomechanics of the cornea change due to the keratectomy and a stable but unpredicted curvature change is obtained. For example, this can happen if the residual stromal thickness was much less than 250 microns but not thin enough to cause long-term destabilization (ectasia). Examples of this will be shown.

For this tutorial, the author groups together both primary undercorrection for corneal causes (mostly biomechanical) and regression (mostly epithelial). The information and data that the author based this tutorial on contribute to ongoing studies to analyze the accuracy of LASIK with respect to epithelial and biomechanical changes. In this study, the author isolates and measures the effect of epithelial and biomechanical changes on the attempted corneal power change.

Fifty-two eyes that underwent routine LASIK between 1998 and 1999 with both the Moria LSK-One (Moria, Antony, France) and Hansatome (Bausch & Lomb, St Louis, Mo) microkeratomes, and with either the Nidek EC5000 (Nidek, Japan) or the B&L 217C (Bausch & Lomb) excimer laser6 were studied. Myopia from -1.00 to -10.25 D was included. Patients were scanned by 3D Artemis VHF digital ultrasound (Ultralink LLC,
St Petersburg, Fla) to obtain the thickness profile and optical power of the epithelium and stroma separately before and after LASIK. The author measured front and back surface curvature of the cornea using the Orbscan II (B&L, St. Louis, Mo) before and at least 3 months after LASIK. Epithelial thickness (ET) and residual stromal bed thickness (RST) 3D maps were produced from the Artemis data. The Orbscan determined the anterior and posterior corneal best-fit spheres (BFS).


Method for Isolating Epithelial and Biomechanical Changes

The curvature of Bowman's surface was calculated from the anterior BFS and the epithelial thickness profile from the Artemis. Gradient optics and lens formulae were used to calculate total corneal power from anterior, Bowman's, and posterior corneal interfaces. Back surface curvature change was defined as a bowing factor. The corneal power change (CPC) was calculated in this manner by comparing the preoperative and postoperative data. To isolate the effects of epithelial and biomechanical changes, the postoperative data were split into the following three permutations:

Epithelial factors: the bowing factor was removed by subtracting the back surface curvature change from each of the anterior, Bowman's, and posterior corneal surfaces.
Bowing factors: the epithelial factor was removed by substituting the postoperative epithelium for the preoperative epithelium.
Remove epithelial and bowing factors: the bowing factor was removed by substituting the postoperative back surface for the preoperative back surface and the epithelial factor was removed by substituting the postoperative epithelium for the preoperative epithelium.
Linear regression and paired t-tests were used to determine the epithelial and/or bowing contributions to the final refraction by correlating the attempted correction to the CPC.

General Observations

The author found that for the cohort of eyes, the minimum RST was 262 microns. Below an RST of 300 microns, postoperative back-surface curvature change correlated strongly with RST (R2=0.5). Attempted vs. achieved subjective refractive change was highly correlated (R2=0.95) with a slope of 0.92. CPC measurement by the calculation method was validated by a high correlation between change in clinical refraction and calculated CPC (R2=0.67, slope=0.90).

Isolating Epithelial and Bowing Factors

As described earlier, attempted correction was correlated with calculated CPC subtracting epithelial factors, bowing factors, and both epithelial and bowing factors. Removing epithelial changes gave a significant change in CPC and increased the slope to 0.94 (R2=0.66), whereas removing bowing gave a significant change in CPC and increased the slope to 0.99 (R2=0.46). Removing both epithelial and bowing factors resulted in a significant difference in CPC, with a correlation slope of 1.03 (R2=0.4, (all P<.01). This led to the conclusion that there were significant biomechanical and epithelial effects occurring, and that corneal elastic bowing and epithelium changes could practically account for the inaccuracy of LASIK.

In the magnitude analysis, mechanical changes accounted for a 15% decrease in intended reduction in central corneal power (P<.001). Epithelial changes accounted for a 5% decrease in intended reduction in central corneal power (P<.001). RST was correlated to the mechanical shifts calculated (R2=0.32). Ablation depth was highly correlated to the mechanical shifts observed (R2=0.89). Thickness of the stromal component of the flap significantly correlated with the spherical equivalent postoperative error (P<.05). Strong significant nonlinear correlations were found between the level of myopia treated and the epithelial (P<.001) or biomechanical (P=.011) power shift measured.

The Epithelium in Regression


The mean central epithelial thickness before surgery was 51 microns (range: 47-62 microns), whereas three months after LASIK, the central epithelium had thickened to an average of 61 microns (range: 44-75 microns). Central thickening amounts to a relative increase in curvature and, therefore, a regression in the myopic refractive effect of LASIK flattening.

In a raw comparison between the error in the postoperative spherical equivalent (all patients had an intended postoperative refractive error of zero) and the epithelial power shift as measured by Artemis scanning, the author found a statistically significant correlation. In other words, the postoperative refractive error could be (at least partly) accounted for by shifts in the power of the epithelium. The fact that these shifts were correlated alone is a testament to the significance of the epithelium in regression, considering the number of biomechanical factors that were also in play. A simple linear regression demonstrated a correlation in which for every diopter of postoperative spherical equivalent error, the epithelium could be accounting for about 25% of the error.

Plotting the level of myopia treated against the amount of epithelial thickening in the center and at the 3-, 4-, 5-, 6-, and 7-mm zones, a strong correlation between amount of epithelial thickening and the level of myopia treated was found. Two things stood out from this analysis. First, more thickening in the central cornea than the peripheral was found. Second, the epithelial thickening response was steep and linear for lower myopia, but appeared to level off as the level of myopia increased, which implies that the epithelium has the ability to reverse central flattening, but only to a certain extent.

To investigate further, the author divided the study eyes into three groups: low, moderate, and high myopia, and determined the thickening profile for each group separately.

The shift in power due to the epithelium will be related to the difference between central and peripheral thickening. For example, if the epithelium were to thicken evenly by 3 microns there would be no power shift (no change in curvature). For the low myopic group, there was considerably more thickening in the center than the periphery-8 microns versus 4 microns, and as myopia increased, the difference between the central and peripheral thickening diminished-in other words, the epithelium appears to be causing regression to a greater extent in lower myopia than higher myopia, despite the fact that there is less absolute thickening in lower myopia.

Thus, the shift in power due to epithelial profile changes was more significant for lower myopia than for higher myopia. Based on the central epithelial thickening reaching a maximum level beyond which increasing myopic ablation depth will not result in further central epithelial thickening while the peripheral epithelium can still thicken for higher myopic ablations as the peripheral ablation depth increases, the author has postulated a hypothesis to explain this shift.

Conclusion

Important nonlinear biomechanical and epithelial effects have been observed and characterized. Biomechanical changes appear well correlated to the residual stromal thickness, which is a function of the total amount of keratectomy, largely determined by the initial corneal thickness and flap thickness. Therefore, it follows that an accurate knowledge of the residual stromal thickness can be important when deciding to perform further enhancement surgery. Knowledge of the mechanical state of the cornea can be obtained by 3D residual stromal thickness mapping as provided by the Artemis. It is important to differentiate regression due to elastic and stable bowing of the cornea (more pronounced for thin residual stromal thickness) from regression due to epithelial changes (thick residual stroma). If the residual stromal thickness is low and responsible for mechanical changes, further tissue removal could, at best, produce an inaccurate result, but may unfortunately risk converting a stable elastic state into an unstable plastic corneal ectasia. This is particularly true of the newer wavefront-guided repair profiles, which aim to reduce spherical aberration and enlarge the optical zone, as they are very tissue intensive. In the final analysis, true customized ablation may require epithelial and biomechanical predictive modeling for achieving low aberration vision.

References

Seitz B, Torres F, Langenbucher A, Behrens A, Suarez E. Posterior corneal curvature changes after myopic laser in situ keratomileusis. Ophthalmology. 2001; 108:666-672; discussion 673.
Roberts C. The cornea is not a piece of plastic. J Refract Surg. 2000; 16:407-413.
Srivannaboon S, Reinstein DZ, Sutton HFS, Silverman RH, Coleman DJ. Effect of epithelial changes on refractive outcome in LASIK. Invest Ophthalmol Vis Sci. 1999; 40:S896.
Reinstein DZ, Srivannaboon S, Sutton HFS, Silverman RH, Shaikh A, Coleman DJ. Risk of Ectasia in LASIK: revised safety criteria. Invest Ophthalmol Vis Sci. 1999; 40:S403.
Barraquer JI. Queratomileusis y queratofakia.
Bogota: Instituto Barraquer de America; 1980.
Reinstein DZ, Srivannaboon S, Silverman RH, Coleman DJ. The accuracy of routine LASIK; isolation of biomechanical and epithelial factors. Invest Ophthalmol Vis Sci. 2000; 41:S318.

Question asked from a reader:

Dr. Dan Reinstein writes;

Quote: In the final analysis, true customized ablation may require epithelial and biomechanical predictive modeling for achieving low aberration vision.

 

Dr. Reinstein, as you know it is very rare for virgin eyes to have high levels of higher order aberration, central flattening, epithelial hyperplasia or excessive bowing. The changes you describe here are caused by an elective, medically unnecessary surgery. Now that you have identified these problems and realize that you can't prevent them, why on earth would you perform even one more surgery on a pair of healthy virgin eyes?

 American Journal of Ophthalmology
March, 1994  

Leo J. Maguire  

 

 

Excerpts:  

"To avoid aberration in the center of the visual field, the cornea must be regular over the entrance pupil".  

"When the cornea is irregular over the entrance pupil, the image generated by the cornea loses contrast and edge definition".  

"The final result is that corneal irregularity from refractive surgery can cause optical degradation; and optical performance in the central field can change with pupil size".  

"To avoid aberration in more peripheral portions of the visual field, the cornea must be regular over the cornea adjacent to the entrance pupil as well as over the entrance pupil itself."  

"First, the pupil enlarges. As it does, aberration of central vision increases as more distorted paracentral cornea falls within the pupillary space."  

"The problems with pupil-related aberration are further magnified by the reality that the Stiles-Crawford effect is negated in night vision."  

"I hope the reader will understand how a patient may have clinically acceptable 20/20 visual acuity in the daytime and still suffer from clinically dangerous visual aberration at night if that patient's visual system must cope with an altered refractive error, increased glare, poorer contrast discrimination, and preferentially degraded peripheral vision. People die at night in motor vehicle accidents four times as frequently as they do during the day, and these figures are adjusted for miles driven. Night driving presents a hazardous visual experience to adults without aberration. When we discuss aberration at night we are considering a possible morbid effect of refractive surgery."

Diffuse Lamellar Keratitis

 


J Refract Surg. 2006;22:441-447

Ahmed Galal, MD, PhD; Alberto Artola, MD, PhD; Jose Belda, MD, PhD; Jose Rodriguez-Prats, MD, PhD; Pascual Claramonte, MD, PhD; Antonio Sánchez, MD, PhD; Oscar Ruiz-Moreno, MD, PhD; Jesús Merayo, MD, PhD; Jorge Alió, MD, PhD

 

PURPOSE: To describe interface corneal edema secondary to steroid-induced elevation of intraocular pressure (IOP) following LASIK.

METHODS: Retrospective observational case series. Diffuse interface edema secondary to steroid-induced elevation of IOP was observed after LASIK simulating diffuse lamellar keratitis (DLK) in 13 eyes. Mean patient age was 31.4±5.3 years. Patients were divided into two groups according to provisional misdiagnosis: DLK group (group 1) comprised 11 eyes and infection group (group 2) comprised 2 eyes (microbial keratitis). Mean follow-up was 8.1±0.5 weeks.

RESULTS: In the DLK group, typical diffuse haze was confined to the interface and extended to the visual axis, impairing vision in all eyes. Provisional diagnosis was late-onset DLK and topical steroids were started. Repeat examination showed elevated IOP as measured at the corneal center and periphery using applanation tonometry (mean 19.1 mmHg and 39.5 mmHg, respectively), causing interface edema with evident interface fluid pockets. Steroids were stopped and topical anti-glaucoma therapy was started. The interface edema decreased and at the end of follow-up the corneal transparency was restored and IOP dropped to normal values. The infection group demonstrated a microbial keratitis-like reaction and underwent flap lifting and interface wound debridement and biopsy with administration of fortified antibiotics and steroids. After elevated IOP was detected, steroids and antibiotics were stopped and topical anti-glaucoma therapy was started, resulting in the resolution of the interface edema.

CONCLUSIONS: Interface fluid syndrome secondary to steroid-induced elevation of IOP might develop in steroid responders after LASIK with a misleading clinical picture simulating DLK or infectious keratitis. Management includes stopping topical steroids and starting topical anti-glaucoma therapy.

Cornea. 2006 May;25(4):388-403. 

Klein SR, Epstein RJ, Randleman JB, Stulting RD. 

From the *Cornea Service, Department of Ophthalmology, Rush University Medical Center, Chicago, IL; and the Department of Ophthalmology, Emory University Medical School, Atlanta, GA. 

 

 

PURPOSE:: To evaluate patients who developed ectasia with no apparent preoperative risk factors. 

 

METHODS:: Potential cases of patients who developed ectasia without apparent risk factors were identified by contacting participants in the Kera-Net (n = 580), ASCRS-Net (n = 450), and ISRS/AAO ISRS-Net (n = 525) internet bulletin boards from April to October 2003. Cases were included if ectasia developed after laser in situ keratomileusis in the absence of apparent preoperative risk factors. Reported cases were excluded for the following reasons: (1) calculated residual stromal bed less than 250 mum, (2) preoperative central pachymetry less than 500 mum, (3) any keratometry reading greater than 47.2 diopters (D), (4) a calculated inferior-superior value greater than 1.4, (5) more than 2 retreatments, (6) attempted initial correction greater than -12.00 D, (7) an Orbscan II "posterior float" (if obtained) greater than 50 mum, and (8) surgical/flap complications. 

 

RESULTS:: A total of 27 eyes of 25 patients were submitted for consideration. Eight eyes (8 patients) met our inclusion criteria. Mean age was 27.7 years (range, 18-41 years). Preoperative manifest refraction spherical equivalent was -4.61 D (range, -2.00 to -8.00 D); steepest keratometric reading was 43.86 D (range, 42.50-46.40 D); keratometric astigmatism was 0.93 D (range, 0.25-1.90 D); and preoperative central pachymetry was 537 mum (range, 505-560 mum). The mean calculated ablation depth was 82.8 mum (range, 21-125.4 mum), and mean calculated residual stromal bed was 299.5 mum (range, 254-373 mum). Mean time to recognition of ectasia onset was 14.2 months (range, 3-27 months) postoperatively. At the time of ectasia diagnosis, the mean manifest refraction spherical equivalent was -1.23 D (range, +0.125 to -3.00) with a mean of 2.72 D (range, 0.75-4.00 D) of astigmatism. 

 

CONCLUSIONS:: Ectasia can occur after an otherwise uncomplicated laser in situ keratomileusis procedure, even in the absence of apparent preoperative risk factors.

BMC Ophthalmol. 2006 Apr 28;6(1):19 

Dada T, Pangtey MS, Sharma N, Vajpayee RB, Jhanji V, Sethi HS. 

 

 

ABSTRACT: 

 

BACKGROUND: Diffuse lamellar keratitis (DLK) is a relatively new syndrome that is increasingly being reported after LASIK. We have observed that a hyperopic shift may be associated with the occurrence of this diffuse lamellar keratitis. 

 

CASE PRESENTATION: A 26 year old man developed bilateral diffuse lamellar keratitis (DLK) following myopic LASIK. The residual refractive error was +0.5D OD and +0.25D OS at the end of the first week. The sterile infiltrates resolved over a period of 4-6 weeks on topical steroid therapy. A progressive hyperopic shift was noted in the right eye with an error +4.25Dsph/+0.25Dcyl 20 at the final follow up 6 months post surgery. 

 

CONCLUSION: Diffuse lamellar keratitis after LASIK may be associated with a significant hyperopic shift.

 Cornea. 2006 Apr;25(3):291-5.

Yeung L, Chen YF, Lin KK, Huang SC, Hsiao CH.


Department of Ophthalmology, Chang Gung Memorial Hospital, Taipei, Taiwan, ROC.

 

PURPOSE: To describe central corneal iron deposition after myopic LASIK.

METHODS: Patients visiting our outpatient clinics between February 2003 and January 2004 and displaying post-LASIK corneal iron deposits were retrospectively enrolled in the study.

RESULTS: Forty-two eyes of 24 patients developed corneal iron deposition after myopic LASIK surgery. All eyes displayed a small, spotty iron deposit located in the center of the corneal flap. The median interval between LASIK and diagnosis of corneal iron deposition was 22.5 months. The spherical equivalents of achieved correction ranged from 4.00 D to 17.50 D.

CONCLUSION: Spotty corneal iron deposition can develop in the center of the corneal flap after myopic LASIK surgery. Because it is asymptomatic, the condition may have been hitherto underestimated in patient populations.

From website:

http://www.birkacre.freeserve.co.uk/spherical_aberration.htm

Spherical aberration is one of the most important problems that can occur after laser eye surgery, in particular with high myopic corrections.

For lenses made with spherical surfaces, rays which are parallel to the optic axis but at different distances from the optic axis fail to converge to the same point. The peripheral light rays are bent more than the central ones as in the following diagram:

A spherical surface has a "Q value" of 0. A surface which is a parabola has the peripheral part of the lens relatively flatter than the centre and so bends the peripheral light rays less, eliminating this spherical aberration. Such a cornea has a negative Q value and has a prolate shape A parabola has a Q value of -0.5. The human eye of a young person has a Q value of -0.5, which is made up of the cornea (Q= -0.25) and the lens of the eye (Q= -0.25) added up together. The over 40y age group has a rounding out of the lens, so its Q value becomes near O. Hence older people have more natural spherical aberration as their Q value is only that of the cornea i.e. -0.25.


There is a nice demonstration of spherical aberration at the
Olympus web site (http://www.olympusmicro.com/primer/java/aberrations/spherical/). The Hubble Space Telescope suffered from spherical aberration when first launched. This was solved by using "adaptive optics", similar to that now being used in excimer lasers. See the Hubble page on this web site: http://www.birkacre.freeserve.co.uk/hubble_space_telescope.htm.)

After a myopic PRK or LASIK, the Q value becomes positive with increased spherical aberration. The cornea then has an oblate shape No normal human cornea is oblate or has a positive Q value. However, all the modern lasers have "blend zones" that smooth off the mid-peripheral "knee" that has a high local Q value and this lessens the induced spherical aberration. e.g. The Technolas 217 laser has true optical zones up to 7mm with a blend zone at least 3mm bigger than this. (the cornea is only about 12.5mm diameter). Similarly the Nidek EC5000 has optical zone up to 6.5mm and the blend zone is adjustable up to 10mm.

Spherical aberration is not really a problem with low myopic corrections but can be a problem with some patients having higher corrections e.g. about about -5 D. The laser manufacturers are tying to improve the shape of the ablation profile to lessen this problem. All the "custom ablations" done by various lasers have totally "aspheric" profiles that have, in theory, no aberrations. However, they can take off more tissue, which can again be a problem with higher corrections as there may not be much to spare. Spherical aberration is not normally a problem in good light but in low light. See night vision: (
http://www.birkacre.freeserve.co.uk/night_vision.htm) and lasik complications: http://www.birkacre.freeserve.co.uk/lasik_complications1.htm).

 J Refract Surg. 2006 Mar;22(3):309-12. Related Articles, Links  

Ramos-Esteban JC, Servat JJ, Tauber S, Bia F.  

Department of Ophthalmology, Yale University School of Medicine, New Haven, Conn, USA 

PURPOSE: To report the history and clinical presentation of a 23-year-old man who developed delayed onset lamellar keratitis in his right eye 2 weeks after uneventful LASIK for correction of myopia.

METHODS: Initial clinical presentation suggested an infectious etiology, which led to therapeutic elevation of the LASIK flap and further microbiologic investigation with bacterial cultures.

RESULTS: Bacterial cultures revealed Bacillus megaterium, which was sensitive to all antibiotics against which it was tested. Twenty-four hours after initiating aggressive topical and oral antibiotic therapy, symptomatic relief occurred in the affected eye. The patient's uncorrected final visual acuity at 1-year follow-up was 20/15 in the right eye, and the stromal bed developed a faint peripheral non-visually significant scar.

CONCLUSIONS: This case is an unusual presentation and course for microbial keratitis following LASIK, which occurred despite aseptic technique and fluoroquinolone antibiotic prophylaxis. Following refractive surgery one should be prepared to culture the lamellar interface in cases of suspected microbial keratitis and begin aggressive antibiotic therapy.

J Cataract Refract Surg 2003; 29:257–263

Michael Bueeler, MSE, Michael Mrochen, PhD, Theo Seiler, MD 

Purpose: To investigate the lateral alignment accuracy needed in wavefront-guided refractive surgery to improve the ocular optics to a desired level in a percentage of normally aberrated eyes.  

Setting: Department of Ophthalmology, University of Zurich, Zurich, Switzerland 

Methods: The effect of laterally misaligned ablations on the optical outcome was simulated using measured wavefront aberration patterns from 130 normal eyes. The calculations were done for 3.0 mm, 5.0 mm, and 7.0 mm pupils. The optical quality of the simulated correction was rated by means of the root-mean-square residual wavefront error.  

Results: To achieve the diffraction limit in 95% of the normal eyes with a 7.0 mm pupil, a lateral alignment accuracy of 0.07 mm or better was required. An accuracy of 0.2 mm was sufficient to reach the same goal with a 3.0 mm pupil.  

Conclusion: Procedures must be developed to ensure that the ablation is within a tolerance range based on each eye's original optical error. Rough centration based on the surgeon's judgment might not be accurate enough to achieve significantly improved optical quality in a high percentage of treated eyes.

J Cataract Refract Surg 2003; 29:250–256

Joseph K.W. Hsu, MD, W. Todd Johnston, MD, Russell W. Read, MD, Peter J. McDonnell, MD, Rey Pangalinan, MD, Narsing Rao, MD Ronald E. Smith, MD 

Purpose: To describe the histopathology of the cornea in 3 cases of corneal melting associated with diclofenac therapy after refractive surgery procedures.  

Setting: Clinic and pathology laboratory.  

Methods: Three cases of corneal melting associated with diclofenac therapy (2 after laser in situ keratomileusis [LASIK] and 1 after mini-radial keratectomy enhancement of a LASIK undercorrection) were studied using patient and referring physician interviews, chart reviews, and histopathologic examination of the corneal tissue.  

Results: In all 3 cases, the flaps were dislocated and the stromal corneal bed was exposed. Diclofenac, generic or brand name, was used in all cases; in 1 case, both generic and brand name were used. Dosing and duration varied, but in all 3 cases diclofenac was used at least 4 times a day for at least 3 days after LASIK. Topical steroids were also prescribed, but 1 patient did not use them. Preoperative medical conditions were present in 2 cases. Histologic analysis showed evidence of an inflammatory response in advanced cases and keratolysis and lack of inflammatory cells in the flaps that were amputated early.  

Conclusions: The use of generic or brand-name diclofenac with or without adjunctive topical steroids after LASIK can be associated with corneal melting when the LASIK flap is dislodged and the corneal stromal bed exposed. Caution is recommended with diclofenac use after LASIK in such cases.

J Cataract Refract Surg 2003; 29:133–137

Dimitrios S. Siganos, MD, PhD, Corina Popescu, MD, Nikolaos Bessis, DOpt, Georgios Papastergiou, MD 

Purpose: To correlate cycloplegic subjective refraction with cycloplegic autorefractometry in eyes that have had LASIK.  

Setting: Vlemma Eye Institute, Athens, Greece 

Methods: Subjective refraction and autorefractometry under cycloplegia were performed in 73 eyes of 46 patients 1, 6, and 12 months after LASIK to correct myopia or myopic astigmatism. The preoperative subjective refraction and autorefractometry under cycloplegia in the same eyes served as controls.    

Results: A statistically significant difference between subjective refraction and autorefraction was found in the sphere and cylinder at all postoperative times. No statistically significant difference was found in the axis. There was no statistically significant difference in the control eyes.  

Conclusions: Automated refractometry in eyes that had had LASIK was reliable in the axis only. Retreatments after LASIK should always be based on subjective refraction.  

J Cataract Refract Surg 2003; 29:118–124

Jay W.W. Chan, MPhil, Marion H. Edwards, PhD, George C. Woo, OD, PhD, Victor C.P. Woo, MD 

Purpose: To develop, evaluate, and use an objective method to determine the effect of LASIK on corneal clarity.  

Setting: Centre for Myopia Research, The Hong Kong Polytechnic University, and the Hong Kong Laser Eye Center, Hong Kong, China 

Methods: Color  photographs of corneal sections were taken using a digital camera and converted to 8-bit gray-scale images. The desired area of the photograph was isolated using a preset mask, and a gray-scale or corneal clarity index of the desired area was obtained by averaging the “intensity” indices of individual pixels within the area. The reliability of the clarity index measures was determined by comparing test and retest measures. The sensitivity of the method was quantified by its ability to identify a small (clinically undetectable) decrease in corneal clarity produced by tight-fitting soft contact lenses worn for 30 minutes. Finally, corneal clarity was measured and compared in 24 patients before and 1 day, 1 week, and 1 month after LASIK.  

Results: The reliability value was 4.11 corneal clarity units, and the change in corneal clarity due to soft contact lens use was 16.24 units. In the LASIK patients, there were statistically significant decreases in corneal clarity from preoperatively to 1 day and 1 week but not to 1 month.  

Conclusions: The method measured changes in corneal clarity that were undetectable clinically and were 4 times greater than 95% of the differences between test and retest measures. The method is therefore reliable and sensitive. Corneal clarity decreased after LASIK and recovered within approximately 1 month.

J Cataract Refract Surg 2002; 28:2088–2095

Francesco Carones, MD, Luca Vigo, MD, Elena Scandola, MD, Letizia Vacchini, MD 

Purpose: To evaluate the results of the prophylactic use of mitomycin-C to inhibit haze formation after excimer laser photorefractive keratectomy (PRK) for medium and high myopia in eyes that were not good candidates for laser in situ keratomileusis (LASIK).   Setting: Carones Ophthalmology Center, Milan, Italy 

Methods: This prospective randomized masked study comprised 60 consecutive eyes (60 patients). The inclusion criteria were a spherical equivalent correction between −6.00 and −10.00 diopters (D) and inadequate corneal thickness to allow a LASIK procedure with a residual stromal thickness of more than 250 μm. The eyes were divided into 2 groups according to the randomization protocol. After PRK, the study group eyes were treated with a single intraoperative dose of mitomycin-C (0.2 mg/mL), applied topically with a soaked microsponge placed over the ablated area and maintained for 2 minutes. The control eyes did not receive this treatment. Refraction, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and slitlamp evidence of corneal opacity (haze) or other visible complications were evaluated.   Results: No toxic or side effects were encountered postoperatively. No study group eye had a haze rate higher than 1 during the 6-month follow-up; 19 eyes (63%) in the control group did (P = .01). At 6 months, the between-group difference in the refractive outcome was statistically significant (P = .05), with 26 study group eyes (87%) and 14 control eyes (47%) within ±0.50 D of the attempted correction. No study group eye had a BCVA loss during the follow-up; 7 control eyes had lost 1 to 3 lines at 6 months (P = .0006).  

Conclusion: The prophylactic use of a diluted mitomycin-C 0.02% solution applied intraoperatively in a single dose after PRK produced lower haze rates, better UCVA and BCVA results, and more accurate refractive outcomes than those achieved in the control group.  

Cornea. 2005 Jul;24(5):509-22.  

Netto MV, Mohan RR, Ambrosio R Jr, Hutcheon AE, Zieske JD, Wilson SE.  The Cole Eye Institute, The Cleveland Clinic Foundation, OH 44195, USA 

PURPOSE: The corneal wound healing response is of particular relevance for refractive surgical procedures since it is a major determinant of efficacy and safety. The purpose of this review is to provide an overview of the healing response in refractive surgery procedures.  

METHODS: Literature review.  

RESULTS: LASIK and PRK are the most common refractive procedures; however, alternative techniques, including LASEK, PRK with mitomycin C, and Epi-LASIK, have been developed in an attempt to overcome common complications. Clinical outcomes and a number of common complications are directly related to the healing process and the unpredictable nature of the associated corneal cellular response. These complications include overcorrection, undercorrection, regression, corneal stroma opacification, and many other side effects that have their roots in the biologic response to surgery. The corneal epithelium, stroma, nerves, inflammatory cells, and lacrimal glands are the main tissues and organs involved in the wound healing response to corneal surgical procedures. Complex cellular interactions mediated by cytokines and growth factors occur among the cells of the cornea, resulting in a highly variable biologic response. Among the best characterized processes are keratocyte apoptosis, keratocyte necrosis, keratocyte proliferation, migration of inflammatory cells, and myofibroblast generation. These cellular interactions are involved in extracellular matrix reorganization, stromal remodeling, wound contraction, and several other responses to surgical injury.  

CONCLUSIONS: A better understanding of the complete cascade of events involved in the corneal wound healing process and anomalies that lead to complications is critical to improve the efficacy and safety of refractive surgical procedures. Recent advances in understanding the biologic and molecular processes that contribute to the healing response bring hope that safe and effective pharmacologic modulators of the corneal wound healing response may soon be developed 

From the conclusion:  

Wouldn't you think they'd want to figure this out before performing refractive surgeons on millions and millions of patients?

J Cataract Refract Surg. 2005 Dec;31(12):2356-62. 

Brown SM, Freedman KA.  Cabarrus Eye Center, Concord, North Carolina 28025, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.  

PURPOSE: To determine whether the currently accepted method of selecting a minimum optical zone diameter for laser refractive surgery that is equal to or slightly greater than the dark-adapted pupil diameter provides a sufficient diameter of corneal surface to focus light arising from objects in the paracentral and peripheral visual field.  

SETTING: Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, Lubbock, Texas, USA 

METHODS: An optical model of the anterior segment was developed to calculate the effective corneal refractive diameter (ECRD), which is the diameter of the area of cornea that refracts all incident light rays arising from an object through the physical pupil (PP). This model incorporates the patient variables of central anterior chamber depth (ACD), central corneal curvature (K(c)), and the diameter of the apparent entrance pupil (EP). The model was expanded to incorporate distant objects off the line of sight (LOS), described by their angular displacement from the fixation object in visual space (the object tangent angle delta(ob)). Results were calculated for the 360 meridian degree visual field (ie, for all objects in visual space perceptually displaced from the fixation object by angle delta(ob)). The effect of the prolate nature of the cornea was also investigated.  

RESULTS: The ECRD expanded rapidly as a function of PP and delta(ob) but was minimally influenced by K(c). Beyond a critical object tangent angle delta(c), light rays striking the corneal vertex were not refracted through the PP, and the ECRD became an annular surface centered on the corneal vertex. The delta(c) was not a function of K, but increased as the PP increased and decreased as the ACD increased. The prolate nature of the cornea had little influence on the ECRD, even for very peripheral light rays.  

CONCLUSIONS: The ECRD expands rapidly when considering distant objects only slightly displaced from the LOS. A patient treated with an optical zone equal to or slightly greater than the dark-adapted pupil diameter may experience vision quality loss for paracentral and midperipheral objects even under conditions of ambient indoor lighting.

This seems like what everyone is saying about LASIK. But who is Sandra Brown, and what happened in the case?

Am J Ophthalmol. 2006 Mar 15;  

Erie JC, Patel SV, McLaren JW, Hodge DO, Bourne WM.  Department of Ophthalmology (J.C.E., S.V.P., J.W.M., W.M.B.).  

PURPOSE: To measure changes in keratocyte density up to 5 years after PRK and LASIK.  

DESIGN: Prospective, nonrandomized clinical trial.  

METHODS: Eighteen eyes of 12 patients received PRK to correct a mean refractive error of -3.73 +/- 1.30 diopters, and 17 eyes of 11 patients received LASIK to correct a mean refractive error of -6.56 +/- 2.44 diopters. Corneas were examined by using confocal microscopy before and 6 months, 1 year, 2 years, 3 years, and 5 years after the procedures. Keratocyte densities were determined in five stromal layers in PRK patients and in six stromal layers in LASIK patients. Differences between preoperative and postoperative cell densities were compared by using paired t tests with Bonferroni correction for five comparisons.  

RESULTS: After PRK, keratocyte density in the anterior stroma decreased by 40%, 42%, 45%, and 47% at 6 months, 2 years, 3 years, and 5 years, respectively (P < .001). At 5 years, keratocyte density decreased by 20% to 24% in the posterior stroma (P < .05). After LASIK, keratocyte density in the stromal flap decreased by 22% at 6 months (P < .02) and 37% at 5 years (P < .001). Keratocyte density in the anterior retroablation zone decreased by 18% (P < .001) at 1 year and 42% (P < .001) at 5 years. At 5 years, keratocyte density decreased by 19% to 22% (P < .05) in the posterior stroma.  

CONCLUSIONS: Keratocyte density decreases for at least 5 years in the anterior stroma after PRK and in the stromal flap and the retroablation zone after LASIK.

 

Surv Ophthalmol. 2005 May-Jun;50(3):245-51.  

Comment in: Surv Ophthalmol. 2005 Nov-Dec;50(6):611-2; author reply 612.  

Bashford KP, Shafranov G, Tauber S, Shields MB.  Department of Ophthalmology and Visual Sciences, Yale University School of Medicine, New Haven, Connecticut; and Glaucoma Consultants of Colorado, P.C., Littleton, Colorado, USA.  

Glaucoma patients present a unique set of challenges to physicians performing corneal refractive surgery. Corneal thickness, which is modified during corneal refractive surgery, plays an important role in monitoring glaucoma patients because of its effect on the measured intraocular pressure. Patients undergo a transient but significant rise in intraocular pressure during the laser-assisted in situ keratomileusis (LASIK) procedure with risk of further optic nerve damage or retinal vein occlusion. Glaucoma patients with filtering blebs are also at risk of damage to the bleb by the suction ring. Steroids, typically used after refractive surgery, can increase intraocular pressure in steroid responders, which is more prevalent among glaucoma patients. Flap interface fluid after LASIK, causing an artificially low pressure reading and masking an elevated pressure has been reported. The refractive surgeon's awareness of these potential complications and challenges will better prepare them for proper management of glaucoma patients who request corneal refractive surgery.

Using Noncontact Tonometry in Patients After Myopic LASIK Surgery

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16331036&query_hl=1  

Cornea. 2006 Jan;25(1):26-28.  

Cheng AC, Fan D, Tang E, Lam DS.  

PURPOSE:: To evaluate the effect of corneal curvature and corneal thickness on the assessment of intraocular pressure (IOP) using noncontact tonometry (NCT) in patients after myopic LASIK surgery.  

METHODS:: All patients who had myopic LASIK in a university-based eye clinic between February 2002 and May 2002 were retrospectively analyzed. Preoperative NCT was compared with postoperative NCT, postoperative corneal thickness, and postoperative corneal curvature.  

RESULTS:: The difference between the mean preoperative NCT (15.46 +/- 2.50 mm Hg) and postoperative NCT (6.30 +/- 1.57 mm Hg) was significant (9.16 +/- 1.96 mm Hg, P < 0.010). Preoperative NCT significantly correlated with postoperative NCT (P < 0.001), postoperative corneal thickness (P = 0.006), and postoperative anterior corneal curvature (P < 0.010).  

CONCLUSIONS:: Both corneal thickness and anterior corneal curvature affect IOP assessment in patients with myopic LASIK. Although correction formulas can be used to estimate the actual IOP, alternative methods should be investigated to assess IOP independent of corneal thickness and curvature.  

"Our model can account for only 47% of the variability in the actual postoperative IOP." 

<<>> 

Excerpts from the full text of the article that was posted above:  

"Laser in situ keratomileusis (LASIK) has gained popularity over recent decades and become a widely accepted type of corneal refractive surgery. During myopic LASIK, corneal stromal ablation with the excimer laser results in reduced corneal thickness and curvature. Such changes affect the measurement of intraocular pressure (IOP).1-6 

Noncontact pneumatic tonometry (NCT) is a simple and safe device for routine IOP measurements. Previous data have shown that NCT can produce accurate IOP assessment comparable to Goldmann tonometry,7-9 which is the gold standard. However, NCT has been shown to underestimate IOP measurements in patients with myopic LASIK in various studies,1-6 and different methods have been proposed to determine the actual IOP.10-13 

Before a better device can be designed, it is important to identify the factors that cause the underestimation in LASIK patients. Although numerous studies have shown that corneal thickness plays an important role,4-9 the effect of corneal curvature is not conclusive.4-9"  

"In a busy refractive clinic, NCT has become a very effective screening tool for the assessment of IOP. However, it has also been shown to underestimate IOP in patients with myopic LASIK.4-8 Therefore, it is important to know the effect of LASIK on IOP measurement by NCT.  

In myopic LASIK, the corneal thickness is reduced. With less corneal tissue producing counterpressure, less force is required to deform the cornea. At the same time, myopic LASIK also flattens the cornea. With a flatter cornea, the anterior corneal surface does not need to deform as much to reach the applanation area.

Although many studies found the association of corneal thickness with manifest IOP,5,10,12,14,15 the results of the association between the IOP and corneal curvature are conflicting.7,9,13,16-20 One of the reasons is that previous studies used the direct keratometry reading obtained from corneal topography or keratometer for the assessment. However, direct keratometry readings from the device are known to be inaccurate in patients after corneal refractive surgery like LASIK.21,22  

With existing keratometers and videokeratoscopes, the radius of curvature of the anterior corneal surface is what is actually measured. The keratometric diopters are derived form radius of curvature using an effective refractive index in a paraxial formula where K = (n - 1)/r. The refractive index between air and the anterior corneal surface is 1.376. Therefore, the refractive power of the anterior corneal surface should be 0.376/r. However, these devices are calibrated to give the true corneal power. The assessment of the true corneal power is based on the assumption that the relationship between the anterior and posterior curvature and the distance between them is a constant. Based on the Gullstrand eye model, the 2 refracting surfaces can be considered as 1 with a fictitious single refractive index of 1.3375. This is the refractive index that most keratometers and videokeratoscopes use.23  

After refractive surgery, the basic assumption no longer holds because the anterior corneal curvature changes and the posterior curvature remains constant. The distance between the 2 refractive surfaces is also significantly reduced. Therefore, the basic assumption of the Gullstrand eye model is no longer valid. The direct keratometry readings from these devices are therefore inaccurate."

...and their impact on intraocular pressure measurements.


Graefes Arch Clin Exp Ophthalmol. 2005 Dec;243(12):1218-20. Epub 2005 Jul 8.


Svedberg H, Chen E, Hamberg-Nystrom H.

St Erik's Eye Hospital, Karolinska Institutet, Polhemsgatan 50, 112 82, Stockholm, Sweden, This email address is being protected from spambots. You need JavaScript enabled to view it..

BACKGROUND: Excimer laser refractive surgery alters the shape and thickness of the cornea by removing central corneal tissue with submicrometer precision. The aim of the study was to analyze the changes in central corneal thickness (CCT) and curvature before and after different excimer laser photorefractive procedures and their possible impact on intraocular pressure (IOP) estimations with Goldmann applanation tonometry.

METHODS: Data on CCT, corneal curvature and IOP readings with Goldmann applanation tonometry before and after excimer laser photorefractive surgery were analyzed retrospectively. The data was further analyzed separately in two subgroups; the photorefractive keratectomy /laser-assisted subepithelial keratomileusis (PRK/LASEK) group and the laser in situ keratomileusis (LASIK) group.

RESULTS: The overall post-operative IOP readings were significantly lower than pre-operative values. There was a significant difference in the lowering of the IOP readings between the two subgroups: LASIK caused a lower IOP reading than PRK/LASEK.

CONCLUSION: The change in corneal thickness and curvature affects the estimation of IOP with Goldmann applanation tonometry after excimer laser photorefractive surgery. The amount of reduction in IOP reading might be influenced by the specific laser surgical procedure. This is of clinical importance in the evaluation of any future glaucoma in the increasing number of patients who undergo photorefractive laser surgery.
Cornea. 2004 Apr;23(3):225-34.

Nordlund ML, Grimm S, Lane S,
Holland EJ.

Cincinnati Eye Institute and Department of Ophthalmology, University of Cincinnati College of Medicine, Cincinnati, OH 45242, USA. This email address is being protected from spambots. You need JavaScript enabled to view it.

PURPOSE: Interface inflammation is a common complication of laser in situ keratomileusis (LASIK). The most well-described presentation is diffuse lamellar keratitis (DLK), which typically develops early after LASIK and responds quickly to topical steroids. In this report, we describe a novel presentation of interface inflammation that resembles DLK in appearance but presents late in the postoperative period, is associated with increased intraocular pressure, and is exacerbated by steroid treatment.

METHODS: A retrospective case series and chart review of all patients treated in our tertiary care private practice for late-onset interface inflammation associated with elevated intraocular pressure.

RESULTS: Ten eyes in 6 patients with late-onset interface inflammation and increased intraocular pressure were identified. At presentation, all patients were presumed to have classic DLK and were treated initially with aggressive topical steroids. Eight of the 10 eyes were receiving topical steroids at the time of presentation. The average time of presentation was 17 days after LASIK (range, 7-34). Elevated intraocular pressure was noted on average 28 days after presentation (range, 8-69). Lamellar inflammation was exacerbated by topical steroids. Resolution of the interface inflammation did not occur until intraocular pressure was controlled.

CONCLUSIONS: This case series describes a clinically distinct form of interface inflammation that presents late and is associated with elevated intraocular pressure. The lamellar inflammation was refractory to topical steroids and only resolved when pressure was controlled. These findings suggest that elevated intraocular pressure can contribute to interface inflammation. Postoperative assessment of intraocular pressure is essential in patients presenting with flap inflammation.
Eye Contact Lens. 2006 Mar;32(2):88-93.  

 

Stapleton F, Hayward KB, Bachand N, Trong PH, Teh DW, Deng KM, Yang EI, Kelly SL, Lette M, Robinson D. 

From the Cornea and Contact Lens Research Unit (F.S., K.B.H., N.B., P.H.T., D.W.H.T., K.M.Y.D., E.I.H.Y.), School of Optometry and Vision Science and Vision Cooperative Research Centre, University of New South Wales, Sydney, Australia; and Sydney Laser and Vision Centre (S.L.K., M.L., D.R.), Bondi Junction, Australia.  

PURPOSE.: To evaluate the effect of laser in situ keratomileusis (LASIK) on corneal sensitivity, nerve morphology, and tear film characteristics.  

METHODS.: A cross-sectional study design was used. Eighteen patients (eight men and 10 women with a mean age of 36.9 +/- 11.2 years) who had undergone bilateral LASIK for low myopia within 18 months of the study and 28 control subjects (16 men and 12 women with a mean age of 27.2 +/- 7.7 years) were enrolled. Central and inferior corneal thresholds to mechanical (air) and chemical (air plus carbon dioxide) stimuli were determined by using a staircase technique. Stimuli of a 1-second duration at 34 degrees C were delivered with a CRCERT-Belmonte aesthesiometer. Images of subbasal nerves in the central cornea were captured with confocal microscopy. Nerve morphology was classified as no nerves, short nerves (<175 mum), or long nerves (>175 mum), with or without interconnections. Noninvasive tear break up time was measured. The phenol red thread test was used to indicate basal tear secretion. Differences between groups were evaluated with analysis of variance, and associations between variables were evaluated with parametric or nonparametric correlation, when appropriate.  

RESULTS.: Central corneal mechanical sensitivity was significantly reduced in the post-LASIK group compared with the control subjects (P<0.001). Nerve morphology was associated with mechanical threshold. Nerve morphology, mechanical sensitivity, and tear breakup time improved during the first 1 to 3 months after surgery, with little change thereafter. Chemical sensitivity was associated with tear secretion (P<0.05).  

CONCLUSIONS.: Central corneal mechanical sensitivity is reduced in patients after LASIK, with partial recovery seen 3 months after surgery. A similar recovery trend is seen for nerve morphology.

Journal of Refractive Surgery Vol. 22 No. 2 February 2006  

Manuel Ramírez, MD; Everardo Hernández-Quintela, MD, MSc; Valeria Sánchez-Huerta, MD; Ramón Naranjo-Tackman, MD  

PURPOSE: To describe the morphological characteristics of microfolds that appear at the corneal flap after LASIK, as seen under confocal microscopy.  

METHODS: Twenty-one eyes that had undergone LASIK were examined, all within 3 weeks to 1 month after surgery. A central scan of the total corneal thickness was obtained by using confocal microscopy in vivo. Confocal images were captured and digitized. The longitudinal orientation (vertical, horizontal, and oblique) and morphological characteristics of the microfolds were described and recorded.  

RESULTS: Six eyes had folds at the central corneal flap, visible as linear distortions in the confocal images: one fold had a vertical orientation, two were horizontal, and three were oblique. The folds were visible from the epithelial basal cell layer to the stromal portion of the flap and were deeper than Bowman’s layer.  

CONCLUSIONS: Confocal microscopy allowed visualization of microfolds after LASIK. With the appropriate software, it is possible to analyze the morphological characteristics of these folds. Flap microfolds after LASIK are deeper than Bowman’s layer.

SOURCE

 

OPTOMETRIST SPECIALIZING IN POST-REFRACTIVE SURGERY DISASTERS CLAIMS THAT FAILED LASIK EYE SURGERY IS DEPLETING SUPPLY OF DONOR CORNEAS...

Dr. Greg Gemoules, OD of Coppell, TX, an Optometrist who specializes in repairing the vision of patients damaged by refractive surgery by fitting them with hard contact lenses, claims that hard contact lenses, known as RGP’s or ‘rigid gas permeable’ lenses are the best option for those with laser-ruined eyesight. One reason he cites to promote RGP use for these visually compromised patients is a lack of availability of donor corneas due to the widespread practice of LASIK eye surgery.

Gemoules also claims that many corneal transplant recipients have worse vision than those with “LASIK difficulties”.

Gemoules stated:

“Many patients with corneal grafts have worse problems than patients with post-LASIK difficulties, and STILL require RGP contact lenses afterwards. Besides, the donor pool for donor corneas is being reduced by the number of patients who are getting LASIK.”

 

Here is an excerpt and link to a comment posted by Optometrist Dr. Greg Gemoules who specializes in the treatment of patients damaged by refractive surgery by fitting them with rigid gas permeable contact lenses.

 

http://www.asklasikdocs.com/forum/main/3821.html

 

Says Dr. Gemoules:

 

"Up to 40% of post-RK patients develop progressive hyperopia because of peripheral corneal ectasia due to the cornea being weakened by the incisions. Taking away tissue from the periphery, as is done with PRK or LASIK will not make the cornea any stronger."

 

 

DrG: The trend now is to ablate more tissue in the periphery in an attempt to reduce spherical aberration that is typically induced by refractive surgery and is responsible for a portion of the night vision disturbances and loss of visual quality experience by refractive surgery patients. We're just now seeing the long term effects of RK. One would expect that other corneal refractive surgical procedures, all of which compromise corneal strength and integrity, will have similar long term effects.

 Noncontact Tonometry in Patients After Myopic LASIK Surgery

 

J Cataract Refract Surg. 2004 May;30(5):1067-72.

Miyata K, Tokunaga T, Nakahara M, Ohtani S, Nejima R, Kiuchi T, Kaji Y, Oshika T.

Miyata Eye Hospital, Miyasaki, Japan.

 

PURPOSE: To prospectively assess the forward shift of the cornea after laser in situ keratomileusis (LASIK) in relation to the residual corneal bed thickness.

 

SETTING: Miyata Eye Hospital, Miyazaki, Japan.

 

METHODS: Laser in situ keratomileusis was performed in 164 eyes of 85 patients with a mean myopic refractive error of -5.6 diopters (D) +/- 2.8 (SD) (range -1.25 to -14.5 D). Corneal topography of the posterior corneal surface was obtained using a scanning-slit topography system before and 1 month after surgery. Similar measurements were performed in 20 eyes of 10 normal subjects at an interval of 1 month. The amount of anteroposterior movement of the posterior corneal surface was determined. Multiple regression analysis was used to assess the factors that affected the forward shift of the corneal back surface.

 

RESULTS: The mean residual corneal bed thickness after laser ablation was 388.0 +/- 35.9 microm (range 308 to 489 microm). After surgery, the posterior corneal surface showed a mean forward shift of 46.4 +/- 27.9 microm, which was significantly larger than the absolute difference of 2 measurements obtained in normal subjects, 2.6 +/- 5.7 microm (P<.0001, Student t test). Variables relevant to the forward shift of the corneal posterior surface were, in order of magnitude of influence, the amount of laser ablation (partial regression coefficient B = 0.736, P<.0001) and the preoperative corneal thickness (B = -0.198, P<.0001). The residual corneal bed thickness was not relevant to the forward shift of the cornea.



CONCLUSIONS: Even if a residual corneal bed of 300 microm or thicker is preserved, anterior bulging of the cornea after LASIK can occur. Eyes with thin corneas and high myopia requiring greater laser ablation are more predisposed to an anterior shift of the cornea.

 Undergoing Excimer Laser Refractive Surgery

 

Cornea. 23, 8 Supplement 1:S59-S64, November 2004.

Kamiya, Kazutaka MD *; Miyata, Kazunori MD +; Tokunaga, Tadatoshi COT +; Kiuchi, Takahiro MD ++; Hiraoka, Takahiro MD ++; Oshika, Tetsuro MD ++

Abstract:

Purpose: To review the time course of corneal anteroposterior shift and refractive stability after myopic excimer laser keratorefractive surgery.

Methods: We examined 65 eyes undergoing photorefractive keratectomy (PRK) and 45 eyes undergoing laser in situ keratomileusis (LASIK). Corneal elevation maps and pachymetry were obtained by scanning-slit corneal topography before; 1 week; and 1, 3, 6, and 12 months after surgery.

Results: Both PRK and LASIK induced significant forward shifts of the cornea. Corneal forward shift was progressive up to 6 months after PRK, but no progression was seen after LASIK. Progressive thinning and expansion of the cornea were not observed after either procedure. The amount of corneal forward shift showed a significant negative correlation with preoperative corneal thickness (r = -0.586; P < 0.01) and a significant positive correlation with the amount of myopic correction (r = 0.504; P < 0.01). A significant correlation was found between the amount of forward shift and the degree of myopic regression after surgery (r = -0.347; P < 0.05).

Conclusion: Myopic PRK and LASIK induce significant forward shifts of the cornea, which are not true corneal ectasia. Eyes with thinner corneas and higher myopia requiring greater ablation are more predisposed to anterior protrusion of the cornea. Corneal forward shift was progressive up to 6 months after PRK but not progressive after LASIK. Forward shift of the cornea can be one of the factors responsible for myopic regression after surgery.

2005 Jan;24(1):92-102.

Pathologic findings in postmortem corneas after successful laser in situ keratomileusis.

Kramer TR, Chuckpaiwong V, Dawson DG, L'Hernault N, Grossniklaus HE, Edelhauser HF.

Emory Eye Center, Emory University, Atlanta, GA 30322, USA. 

 

SOURCE

 

PURPOSE: To examine the histologic and ultrastructural features of human corneas after successful laser in situ keratomileusis (LASIK).

 

METHODS: Corneas from 48 eyes of 25 postmortem patients were processed for histology and transmission electron microscopy (TEM). The 25 patients had LASIK between 3 months and 7 years prior to death. Evaluation of all 5 layers of the cornea and the LASIK flap interface region was done using routine histology, periodic acid-Schiff (PAS)-stained specimens, toluidine blue-stained thick sections, and TEM.

 

RESULTS: In patients for whom visual acuity was known, the first postoperative day uncorrected visual acuity was 20/15 to 20/30. In patients for whom clinical records were available, the postoperative corneal topography was normal and clinical examination showed a semicircular ring of haze at the wound margin of the LASIK flap. Histologically, the LASIK flap measured, on average, 142.7 microm (range, 100-200). A spectrum of abnormal histopathologic and ultrastructural findings was present in all corneas. Findings at the flap surface included elongated basal epithelial cells, epithelial hyperplasia, thickening and undulations of the epithelial basement membrane (EBM), and undulations of Bowman's layer. Findings in or adjacent to the wound included collagen lamellar disarray; activated keratocytes; quiescent keratocytes with small vacuoles; epithelial ingrowth; eosinophilic deposits; PAS-positive, electron-dense granular material interspersed with randomly ordered collagen fibrils; increased spacing between collagen fibrils; and widely spaced banded collagen. There was no observable correlation between postoperative intervals and the severity or type of pathologic change except for the accumulation the electron-dense granular material.

 

CONCLUSIONS: Permanent pathologic changes were present in all post-LASIK corneas. These changes were most prevalent in the lamellar interface wound. These changes along with other pathologic alterations in post-LASIK corneas may change the functionality of the cornea after LASIK.

 

Invest Ophthalmol Vis Sci. 2004 Nov;45(11):3991-6.

Corneal reinnervation after LASIK: prospective 3-year longitudinal study.

Calvillo MP, McLaren JW, Hodge DO, Bourne WM.

Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.

 

SOURCE

 

PURPOSE: To measure the return of innervation to the cornea during 3 years after LASIK.

METHODS: Seventeen corneas of 11 patients who had undergone LASIK to correct myopia from -2.0 D to -11.0 D were examined by confocal microscopy before surgery, and at 1, 3, 6, 12, 24, and 36 months after surgery. In all available scans, the number of nerve fiber bundles and their density (visible length of nerve per frame area), orientation (mean angle), and depth in the cornea were measured.

RESULTS: The number and density of subbasal nerves decreased >90% in the first month after LASIK. By 6 months these nerves began to recover, and by 2 years they reached densities not significantly different from those before LASIK. Between 2 and 3 years they decreased again, so that at 3 years the numbers remained <60% of the pre-LASIK numbers (P <0.001). In the stromal flap most nerve fiber bundles were also lost after LASIK, and these began recovering by the third month, but by the third year they did not reach their original numbers (P <0.001). In the stromal bed (posterior to the LASIK flap interface), there were no significant changes in nerve number or density. As the subbasal nerves returned, their mean orientation did not change from the predominantly vertical orientation before LASIK. Nerve orientation in the stromal flap and the stromal bed also did not change.

CONCLUSIONS: Both subbasal and stromal corneal nerves in LASIK flaps recover slowly and do not return to preoperative densities by 3 years after LASIK. The numbers of subbasal nerves appear to decrease between 2 and 3 years after LASIK. The orientation of the regenerated subbasal nerves remains predominantly vertical.

 

http://www.journalofrefractivesurgery.com/showAbst.asp?thing=10147

 

Journal of Refractive Surgery Vol. 21 No. 2 March/April 2005

"In particular, a forward shift and an increase in power of the posterior surface was predicted for myopic LASIK, in agreement with previous experimental findings."          

 

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12701715&query_hl=21

1995

 

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=7549317&query_hl=2

Ophthalmologe. 1995 Aug;92(4):389-96.

 

OBJECTIVE: To analyze critically refractive surgery of the cornea by excimer laser and to compare laser surgery with other methods of treatment of refractive errors of the eye.

MATERIAL AND METHODS: This analysis has to be restricted to a comparison of the treatment of myopia by keratotomy and photoablation with the ArF excimer laser. Correction of hypermetropia and of astigmatismus has to be left out, along with all the other methods to correct myopia, such as glasses, contact lenses, keratomileusis, epikeratoplasty, alloplastic implants, implantation of intraocular lenses with negative power, and replacement of the clear lens by an posterior chamber lens. The essential literature is screened. For intrastromal ablation with the picosecond Nd:YLF laser we relay on own experiences, also with the use of the ArF excimer laser we are not without own experiences.

RESULTS AND STATEMENTS: For comparison of refractive surgery of the cornea not only the PERK study and the recommendations of the American Academy of Ophthalmology have to be considered, but also the newest developments in radial keratotomy such as two-step incision and reoperation with reopening of the keratotomy wounds. With these techniques the same precision can be reached as with the excimerlaser, and also higher myopias can be corrected. The dangers of the procedure, such as infection, perforation at surgery or laceration by contusion remain much larger. Intrastromal photoablation did not reach clinical maturity. Superficial photoablation is an almost safe procedure. A reduction of 3 D of myopia can be reached with satisfying precision, although higher myopias are still a problem. Pain following the ablation is considerable. Haze and disturbed vision at night can be present; infectious keratitis is rare, but possible.

CONCLUSIONS: The critical fact of both procedures, keratotomy and photoablation with excimer laser, remains that healthy eyes are treated; therefore, even rare complications weigh much heavier than if sick eyes are treated. Because this is cosmetic surgery, the individuum asking for this type of procedure has to pay for on his own. Olson demands: "In determining when new technology is acceptable, we must consider the financial cost and the expected benefit to society. Is it an equitable tradeoff?" If we look at refractive surgery, especially laser photoablation, in the context of the needs for ophthalmic care of the whole world, then this type of surgery is out of proportion. The balance could be restored if, with every laser application, funds were given for third-world projects. Excimer-laser surgery may be justified insofar as the research with these lasers leads to useful therapeutic methods.

 and clinical correlations

 

Schmack I, Dawson DG, McCarey BE, Waring GO 3rd, Grossniklaus HE, Edelhauser HF.

Emory Eye Center, Emory University School of Medicine, Atlanta, GA 30322, USA.

 

 

PURPOSE: To measure the cohesive tensile strength of human LASIK corneal wounds.

METHODS: Twenty-five human eye bank corneas from 13 donors that had LASIK were cut into 4-mm corneoscleral strips and dissected to expose the interface wound. Using a motorized pulling device, the force required to separate the wound was recorded. Intact and separated specimens were processed for light and electron microscopy. Five normal human eye bank corneas from 5 donors served as controls. A retrospective clinical study was done on 144 eyes that had LASIK flap-lift retreatments, providing clinical correlation.

RESULTS: The mean tensile strength of the central and paracentral LASIK wounds showed minimal change in strength over time after surgery, averaging 2.4% (0.72 +/- 0.33 g/mm) of controls (30.06 +/- 2.93 g/mm). In contrast, the mean peak tensile strength of the flap wound margin gradually increased over time after surgery, reaching maximum values by 3.5 years when the average was 28.1% (8.46 +/- 4.56 g/mm) of controls. Histologic and ultrastructural correlative studies found that the plane of separation always occurred in the lamellar wound, which consisted of a hypocellular primitive stromal scar centrally and paracentrally and a hypercellular fibrotic stromal scar at the flap wound margin. The pathologic correlations demonstrated that the strongest wound margin scars had no epithelial cell ingrowth-the strongest typically being wider or more peripherally located. In contrast, the weakest wound margin scars had epithelial cell ingrowth. The clinical series demonstrated the ability to lift LASIK flaps without complications during retreatments up to 8.4 years after initial surgery, correlating well with the laboratory results.

CONCLUSIONS: The human comeal stroma typically heals after LASIK in a limited and incomplete fashion; this results in a weak, central and paracentral hypocellular primitive stromal scar that averages 2.4% as strong as normal comeal stroma. Conversely, the LASIK flap wound margin heals by producing a 10-fold stronger, peripheral hypercellular fibrotic stromal scar that averages 28.1% as strong as normal comeal stromal, but displays marked variability.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15604873&query_hl=13

Cornea. 2005 Jan;24(1):92-102. Related Articles, Links

Pathologic findings in postmortem corneas after successful laser in situ keratomileusis.

Kramer TR, Chuckpaiwong V, Dawson DG, L'Hernault N, Grossniklaus HE, Edelhauser HF.

Emory Eye Center, Emory University, Atlanta, GA 30322, USA.

 

PURPOSE: To examine the histologic and ultrastructural features of human corneas after successful laser in situ keratomileusis (LASIK).

METHODS: Corneas from 48 eyes of 25 postmortem patients were processed for histology and transmission electron microscopy (TEM). The 25 patients had LASIK between 3 months and 7 years prior to death. Evaluation of all 5 layers of the cornea and the LASIK flap interface region was done using routine histology, periodic acid-Schiff (PAS)-stained specimens, toluidine blue-stained thick sections, and TEM.

RESULTS: In patients for whom visual acuity was known, the first postoperative day uncorrected visual acuity was 20/15 to 20/30. In patients for whom clinical records were available, the postoperative corneal topography was normal and clinical examination showed a semicircular ring of haze at the wound margin of the LASIK flap. Histologically, the LASIK flap measured, on average, 142.7 microm (range, 100-200). A spectrum of abnormal histopathologic and ultrastructural findings was present in all corneas. Findings at the flap surface included elongated basal epithelial cells, epithelial hyperplasia, thickening and undulations of the epithelial basement membrane (EBM), and undulations of Bowman's layer. Findings in or adjacent to the wound included collagen lamellar disarray; activated keratocytes; quiescent keratocytes with small vacuoles; epithelial ingrowth; eosinophilic deposits; PAS-positive, electron-dense granular material interspersed with randomly ordered collagen fibrils; increased spacing between collagen fibrils; and widely spaced banded collagen. There was no observable correlation between postoperative intervals and the severity or type of pathologic change except for the accumulation the electron-dense granular material.

CONCLUSIONS: Permanent pathologic changes were present in all post-LASIK corneas. These changes were most prevalent in the lamellar interface wound. These changes along with other pathologic alterations in post-LASIK corneas may change the functionality of the cornea after LASIK.

To understand the extent of the damage, you really should get the full-text of this article.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15808255&query_hl=16

1: Ophthalmology. 2005 Apr;112(4):634-44.

Dawson DG, Holley GP, Geroski DH, Waring GO 3rd, Grossniklaus HE, Edelhauser HF.

Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA.

 

OBJECTIVE: To perform confocal microscopy on postmortem human LASIK corneas and correlate these findings to histologic and ultrastructure evaluations.

DESIGN: Prospective, consecutive, observational case series.

PARTICIPANTS: Ninety postmortem LASIK corneas (47 patients) were evaluated for histopathology, of which 22 consecutive corneas (12 patients) were also evaluated by confocal microscopy. Six normal corneas (3 patients) served as controls.

METHODS: This observational case series involving 22 corneas from 12 patients with postoperative intervals from 1 month to 6.5 years after LASIK surgery were collected. The corneas were mounted in an artificial anterior chamber and perfused with balanced salt solution before confocal microscopy was performed on the center of the cornea. The corneas were then bisected and processed for light and transmission electron microscopy.

RESULTS: Confocal microscopy, along with histologic and ultrastructural correlations, demonstrated that the most prevalent alterations in the centers of LASIK corneas were a slightly thickened epithelium caused by focal basal epithelial cell hypertrophic modifications, random undulations in Bowman's layer over the flap surface, and a variably thick hypocellular primitive stromal interface scar. By using confocal microscopy, the interface wound was easily identified in 100% of the cases because numerous brightly reflective interface particles were always present in the hypocellular primitive stromal scar. These particles were found primarily to consist of organic cellular constituents, some of which were transient in nature.

CONCLUSION: After LASIK, active stromal wound healing in the central cornea results in the production of a hypocellular primitive stromal scar, whereas secondary tissue adjustments seem to cause the Bowman's layer undulations and the subsequent epithelial cell modifications. Most of the interface particles revealed by confocal microscopy in the region of the stromal scar are organic in nature and presumably innocuous to the cornea.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15505047&query_hl=9

Invest Ophthalmol Vis Sci. 2004 Nov;45(11):3991-6.

Calvillo MP, McLaren JW, Hodge DO, Bourne WM.

Department of Ophthalmology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.

 

PURPOSE: To measure the return of innervation to the cornea during 3 years after LASIK.

METHODS: Seventeen corneas of 11 patients who had undergone LASIK to correct myopia from -2.0 D to -11.0 D were examined by confocal microscopy before surgery, and at 1, 3, 6, 12, 24, and 36 months after surgery. In all available scans, the number of nerve fiber bundles and their density (visible length of nerve per frame area), orientation (mean angle), and depth in the cornea were measured.

RESULTS: The number and density of subbasal nerves decreased >90% in the first month after LASIK. By 6 months these nerves began to recover, and by 2 years they reached densities not significantly different from those before LASIK. Between 2 and 3 years they decreased again, so that at 3 years the numbers remained <60% of the pre-LASIK numbers (P <0.001). In the stromal flap most nerve fiber bundles were also lost after LASIK, and these began recovering by the third month, but by the third year they did not reach their original numbers (P <0.001). In the stromal bed (posterior to the LASIK flap interface), there were no significant changes in nerve number or density. As the subbasal nerves returned, their mean orientation did not change from the predominantly vertical orientation before LASIK. Nerve orientation in the stromal flap and the stromal bed also did not change.

CONCLUSIONS: Both subbasal and stromal corneal nerves in LASIK flaps recover slowly and do not return to preoperative densities by 3 years after LASIK. The numbers of subbasal nerves appear to decrease between 2 and 3 years after LASIK. The orientation of the regenerated subbasal nerves remains predominantly vertical.

Ophthalmology. 2002 Apr;109(4):659-65.  

Hamilton DR, Manche EE, Rich LF, Maloney RK.  Jules Stein Eye Institute, University of California-Los Angeles, Los Angeles, CA 90095, USA.  

PURPOSE: To report the ocular manifestations and clinical course of eyes developing interface fluid after laser in situ keratomileusis (LASIK) surgery from a steroid-induced rise in intraocular pressure.  

DESIGN: Retrospective, noncomparative interventional case series.  

PARTICIPANTS/INTERVENTION: We examined six eyes of four patients who had diffuse lamellar keratitis develop after uneventful myopic LASIK surgery and were treated with topical corticosteroids.  

PRINCIPAL OUTCOME MEASURE: Slit-lamp findings, intraocular pressure measurements, and visual field loss.

RESULTS: All eyes had a pocket of fluid develop in the lamellar interface between the flap and the stromal bed associated with a corticosteroid-induced rise in intraocular pressure. However, because of the interface fluid, intraocular pressure was normal or low by central corneal Goldmann applanation tonometry in all eyes. The elevated intraocular pressure was diagnosed by peripheral measurement in several cases after months of elevated pressure. All six eyes had visual field defects develop. Three eyes of two patients had severe glaucomatous optic neuropathy and decreased visual acuity develop as a result of undiagnosed steroid-induced elevated intraocular pressure.  

CONCLUSIONS: A steroid-induced rise in intraocular pressure after LASIK can cause transudation of aqueous fluid across the endothelium that collects in the flap interface. The interface fluid leads to inaccurately low central applanation tonometry measurements that obscure the diagnosis of steroid-induced glaucoma. Serious visual loss may result.

J Cataract Refract Surg. 2002 Feb;28(2):356-9.  

Shaikh NM, Shaikh S, Singh K, Manche E.  Department of Ophthalmology, Stanford University School of Medicine, Stanford, California 94305, USA 

We describe 2 patients, one a glaucoma suspect because of family history and the other with juvenile glaucoma. Both patients developed complications after laser in situ keratomileusis that required frequent topical steroids, leading to steroid-induced glaucoma. In both cases, corneal edema from the acute rise in intraocular pressure (IOP) caused inaccurate IOP measurement by standard methods. The inability to recognize glaucoma early may have resulted in significant irreversible vision loss.

Ophthalmology. 2005 Jul;112(7):1207-12.   

Arevalo JF, Mendoza AJ, Velez-Vazquez W, Rodriguez FJ, Rodriguez A, Rosales-Meneses JL, Yepez JB, Ramirez E, Dessouki A, Chan CK, Mittra RA, Ramsay RC, Garcia RA, Ruiz-Moreno JM.  Retina and Vitreous Service, Clinica Oftalmologica Centro Caracas, Caracas, Venezuela. This email address is being protected from spambots. You need JavaScript enabled to view it.  

PURPOSE: To describe 19 patients (20 eyes) who developed a macular hole (MH) after undergoing bilateral LASIK for the correction of myopia.  

DESIGN: Noncomparative, interventional, retrospective, multicenter case series.  

PARTICIPANTS: Nineteen patients (20 eyes) who developed an MH after bilateral LASIK for the correction of myopia at 10 institutions in Venezuela, Colombia, Puerto Rico, Spain, and the United States.  

METHODS: Chart review.  

MAIN OUTCOME MEASURE: Macular hole development.  

RESULTS: The MH formed between 1 to 83 months after LASIK (mean, 12.1). In 60% of cases, the MH developed < or =6 months after LASIK, and in 30% of cases it developed > or =1 year after LASIK. Eighteen of 19 (94.7%) patients were female. Mean age was 46 years (range, 25-65). All eyes were myopic (range, -0.50 to -19.75 diopters [mean, -8.9]). Posterior vitreous detachment was not present before and was documented after LASIK in 55% of eyes. A vitrectomy closed the MH on the 14 eyes that underwent surgical management, with an improvement of final best-corrected visual acuity in 13 of 14 (92.8%) patients. Our 20 eyes with a full-thickness MH after LASIK reflect an incidence of approximately 0.02% (20/83938).  

CONCLUSION: An MH may infrequently develop after LASIK for the correction of myopia. Our study shows that vitreoretinal surgery can be successful in restoring vision for most myopic eyes with an MH after LASIK. Vitreoretinal interface changes may play a role in MH formation after LASIK for the correction of myopia.

Ophthalmologe. 2006 Feb 8; [Epub ahead of print]

[Article in German]

Knorz MC.

FreeVis LASIK Zentrum, Universitatsklinikum Mannheim, .

In surface ablation, haze is the most frequent complication.After LASIK, microkeratome-related complications are rare today and usually resolve without sequelae, provided no ablation was done. Postoperative flap complications such as flap slippage usually occur during the first few days after surgery and should be treated as early whenever present.Interface complications are a new diagnostic entity as the interface between flap and stroma presents a space where fluid or cells can accumulate. Diffuse lamellar keratitis usually occurs within the first few postoperative days and should be treated aggressively to avoid scarring. Epithelial ingrowth is another rare complication usually requiring treatment. Corneal hydrops with fluid accumulation in the interface is a very rare but important phenomenon related to steroid-induced glaucoma but presenting with false low tonometry readings.Corneal ectasia is extremely rare and in most cases related to thin stromal beds. However, its pathogenesis is not yet completely understood, and it may occur in "normal" eyes, too. Dry eye syndrome is the most frequent complication after LASIK. It is usually benign but may cause significant visual impairment in rare cases.

Lamellar keratitis following LASIK

 

Ophthalmol Clin North Am. 2002 Mar;15(1):35-40.  

Chao CW, Azar DT.  Division of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, 243 Charles Street, Boston, MA 02114, USA.  

Distinguishing between an infectious or sterile lamellar keratitis is the most important first step in evaluating patients with interface infiltrates after LASIK. The mechanisms by which infectious keratitis develops are more straightforward than for DLK and deal with the introduction of microbial pathogens into the lamellar flap during LASIK. Prevention emphasizes reducing contamination risks and treating any pre-existing ocular infections. The mechanisms of the development of DLK are likely multifactorial, and factors such as microkeratome debris, eyelid secretions, other debris, epithelial defects, and bacterial endotoxin have been suggested. Overall, much remains to be elucidated in order to devise effective prevention measures.

Several more studies related to Diffuse Lamellar Keratitis submitted, with commentary (italics) from an avid reader:

 

Ophthalmology. 1998 Sep;105(9):1721-6.  

Diffuse lamellar keratitis. A new syndrome in lamellar refractive surgery.  

Smith RJ, Maloney RK.  Jules Stein Eye Institute, UCLA School of Medicine, USA.  

OBJECTIVE: This study aimed to describe a syndrome that the authors call diffuse lamellar keratitis that follows laser in situ keratomileusis (LASIK) and related lamellar corneal surgery.

DESIGN: Noncomparative case series and record review.  

PARTICIPANTS: Thirteen eyes of 12 patients in whom infiltrates developed in the interface after lamellar refractive surgery were studied.  

INTERVENTION: Topical antibiotics or corticosteroids or both were administered.  

MAIN OUTCOME MEASURES: Corneal infiltrate appearance, focality, location, and clinical course were measured.  

RESULTS: Patients presented between 2 and 6 days after surgery with pain, photophobia, redness, or tearing. Ten cases directly followed either myopic keratomileusis or LASIK. Three cases followed enhancement surgery without the use of a microkeratome. All 13 cases had infiltrates that were diffuse, multifocal, and confined to the flap interface with no posterior or anterior extension. The overlying epithelium was intact in each case. Cultures were negative in the two cases cultured. Ten eyes were treated with antibacterial agents; two eyes had fluorometholone four times daily added to the routine postoperative antibacterial regimen, and one eye had the antibacterial agent discontinued and was treated with topical fluorometholone alone. All infiltrates resolved without sequelae.  

CONCLUSIONS: A distinct syndrome of unknown cause of noninfectious diffuse infiltrates in the lamellar interface is described. It can be distinguished from infectious infiltrates by clinical presentation and close follow-up. Patients with the syndrome should be spared the more invasive treatment of infectious keratitis.  

DLK was unheard of before LASIK, yet since LASIK there have been thousands of cases, numerous reports in the medical literature as well as a hot topic in the industry tabloids.  

One of the first things that came to mind was the article that appeared in the JRS in 2002 titled "A Mysterious Tale: A Search for the Cause of 100+ Cases of Diffuse Lamellar Keratitis". It was submitted for publication anonymously. Surgeon X had a DLK rate at one point as high as 50%. For those who are unfamiliar with DLK, it can cause permanent vision loss from scarring, or even loss of the cornea entirely. I found it unbelievable that this surgeon continued performing LASIK while he "searched for the cause". Do you think he informed his patients that his rate of DLK was 50%? Sounds like he used his patients as human guinea pigs.

 

LASIK is an elective surgery performed on a vital sensory organ. I see people comparing it to other elective surgeries. It is your eyes, your vision, your primary interface with the world! Come on, that's not the same as other elective surgeries. This kind of elective surgery should be held to much, much higher standards because vision is so precious and so important to a person's overall well-being and quality of life. A person presenting for LASIK is not sick, does not have a disease, and lives a perfectly normal life with great correctable vision.  I have such a hard time understanding how "doctors" can promote a surgery that triggers so many adverse, life-altering "side effects" in a normal healthy human being.  

DLK is not the only new syndrome induced by LASIK.  "Neurotrophic keratopathy" and "neurotrophic epitheliopathy" are terms used to describe LASIK induced dry eye which results from the severing of the corneal nerves by the microkeratome. Doctors routinely tell their patients that dry eyes is a temporary condition and advise the use of artificial tears for a period of weeks. The brochure given out by my LASIK surgeon said that eye drops are only needed for 2 weeks. Excuse me, it's over 5 years later, and I still use eye drops daily due to horrible dry eye with associated pain and burning.

One peer-reviewed article showed that at 3 years post-op the corneal nerves were still less than 60% of pre-op densities. No article has ever shown that the nerves fully recover to their normal patterns. Yet surgeons don't inform patients that their corneal nerves will be permanently damaged.  There's another new syndrome of the Intralase flap. Patients were coming back in the early post-op period with such extreme light sensitivity that they had to wear dark sunglasses indoors. Surgeons were so puzzled by this that it left them scratching their heads.

Finally one surgeon coined the term "Transient Light Sensitivity", or TLS for short, and it made them all very happy that now there was a term for it. Now, instead of looking like a moron to their patients because they didn't have a diagnosis, they could say "Oh, you have TLS", give them some steroids and a pat on the head and send them on their way. (be sure to warn your patients of the dangers of prolonged steriod use and monitor their IOP closely!)

This article shows that patients who think they are out of the woods because one day or one week post-op they have 20/20 acuity and no complications could be in for an unpleasant late surprise. 

  Reports: Diffuse Lamellar Keratitis 6 Months After Uneventful Laser in situ Keratomileusis  

Journal of Refractive Surgery Vol. 19 No. 1 January/February 2003

 

José I. Belda, MD, PhD; Alberto Artola, MD, PhD; Jorge Alió, MD, PhD  

PURPOSE Diffuse lamellar keratitis after laser in situ keratomileusis (LASIK) typically occurs between 1 and 7 days after the procedure, and its etiologic factor(s) remain unknown.  

METHODS We describe a case of diffuse lamellar keratitis 6 months after uneventful LASIK in a 25-year-old woman.  

RESULTS Slit-lamp microscopy showed a diffuse infiltrate confined to the interface, extending to the visual axis, with no other relevant findings. Late on-set diffuse lamellar keratitis was our provisional diagnosis and treatment with topical corticosteroids was instituted, with rapid response and improvement of the clinical signs and symptoms.  

CONCLUSIONS This case supports the theory that a previously inert inciting agent could cause a delayed toxic or inflammatory response of the cornea several months after surgery.

[J Refract Surg 2003;19:70-71]  From the full text: "Possible etiologies include metallic debris from the microkeratome or blade, bacterial endotoxins, meibomian gland oils, debris from corneal ablation or from absorbent sponges, povidone-iodine solutions, and surgical glove talc."

Diffuse lamellar keratitis complicating laser in situ keratomileusis Post-marketing surveillance of an emerging disease in British Columbia, Canada, 2000-2002.

 

J Cataract Refract Surg. 2005 Dec;31(12):2340-2344  

Bigham M, Enns CL, Holland SP, Buxton J, Patrick D, Marion S, Morck DW, Kurucz M, Yuen V, Lafaille V, Shaw J, Mathias R, Vanandel M, Peck S.  

PURPOSE: To describe a surveillance system and summarize data between January 2000 and December 2002 regarding diffuse lamellar keratitis (DLK), a complication of laser in situ keratomileusis (LASIK) surgery.  

SETTING: Community-based clinics in British Columbia, Canada, in which LASIK surgery is performed.  

METHODS: Monthly, all clinics in which LASIK is performed reported the number of LASIK procedures and nonnominal cases of DLK (by grade and onset date) to the British Columbia Centre for Disease Control. Diffuse lamellar keratitis outbreaks were investigated, and prevention and control measures were recommended.  

RESULTS: From 2000 to 2002, approximately 72 000 LASIK procedures were performed, with a mean DLK incidence rate of 0.67% (95% confidence interval, 0.61-0.73). The overall proportion of DLK cases attributed to outbreaks was 64%, decreasing from 72% in 2000 to 40% in 2003.  

CONCLUSIONS: An effective DLK surveillance program was implemented at all laser refractive clinics in British Columbia. Reported DLK incidence was 0.67 cases per 100 procedures, with 64% occurring in outbreaks.

Journal of Refractive Surgery Vol. 22 No. 2 February 2006  

Ching-Liang Kuo, MD; Hsiu-Fen Lin, MD; Po-Chiung Fang, MD; Hsi-Kung Kuo, MD; David Hui-Kang Ma, MD, PhD  

PURPOSE: To report a case of late onset lamellar keratitis and epithelial ingrowth associated with orbital cellulitis 1 month after LASIK surgery.  

METHODS: A 19-year-old patient presented with pain and subsequent blurry vision in the right eye. One month prior to presentation, he had undergone LASIK in both eyes. Orbital cellulitis was suspected.  

RESULTS: Under aggressive treatment, the patient recovered from orbital cellulitis and lamellar keratitis and he also regained his vision with topical steroid treatment.  

CONCLUSIONS: Lamellar keratitis does not always occur early following LASIK and may be associated with orbital cellulitis.  

[J Refract Surg. 2006;22:202-204.]  

Here is a link to a description of orbital cellulitis:  

http://www.eyemdlink.com/Condition.asp?ConditionID=477

http://www.crstodayarchive.com/03_archive/0503/17.html  

Cataract & Refractive Surgery Today May, 2003  

Spherical Aberration and Its Symptoms  Theories on why it occurs and how new technology may address the problem.  

BY MARIA REGINA CHALITA, MD, AND RONALD R. KRUEGER, MD, MSE  

Excerpt:  

SYMPTOMS CORRELATED WITH SPHERICAL ABERRATIONS: Standard laser refractive surgery performed on patients with large scotopic pupil sizes is associated with nighttime vision problems such as halos.12 The increased amount of higher-order aberrations after standard LASIK is consistent with the relatively common patient comment, “I can read 20/20, but my vision is not as good as it was before.”13   We analyzed 105 eyes that underwent LASIK correction and correlated their symptoms with higher-order aberrations. Our analysis of optical symptoms and measured aberrations for a scotopic pupil size showed a statistically significant correlation between higher-order aberrations and glare (P=.041) as well as starburst (P=.004). When we broke down these aberrations into individual Zernike components, spherical aberration was the predominant cause, with a statistically significant correlation to glare (P=.010) and starburst (P=.014). Halos seemed to be associated with spherical aberration for the scotopic pupil size (P=.053). Table 1 shows the relationship of spherical aberration and coma with patients’ symptoms.  

SPHERICAL ABERRATION PREVENTION AND CORRECTION: Surgeons must exercise care when treating eyes with larger scotopic pupils, especially if the procedure is expected to induce higher levels of spherical aberration (patients with large pupils will experience more symptoms with higher levels of spherical aberration). Customized laser ablations attempt to minimize these symptoms by more effectively avoiding laser-induced spherical aberrations. The ideal ablation profile for correcting refractive error without generating spherical aberration is to reshape the cornea with a lesser radius of curvature in the midperiphery rather than in the center. This difference in asphericity corrects the spherical aberration of the eye, because the flatter surface will cause less refraction of the peripheral rays.14

JRS September/October 2005 21:5 p502.
Lin and Tsai.
Retinal Plebitis After LASIK

 

Excerpt:

"An IOP of at least 65mmHg is necessary to create a corneal flap with the microkeratome. During this time, the shape of the anterior segment may change rapidly and structures posterior to the suction ring are also compressed in sequence. When the suction stops and the suction ring is released, ocular decompression leads to dynamic equatorial elongation and anterior-posterior contraction. This barotrauma is analagous to what happens in closed eye injury, and can alter delicate retinal structures, especially small vessels, and induce vitreoretinal traction at the vitreous base and posterior pole. Sudden elevation of IOP also disturbs the retinal circulation and increases venous pressure, which results in retinal ischemia. All of these conditions may aggravate the original impaired blood-retinal barrier in highly myopic eyes and increase vascular permeability, leading to the loss of integrity of tight junctions of endothelial cells. Laser in-situ keratomilieusis-induced shock waves can generate up to 100atm. Although the pressure decreases steadily to values below 10 bars toward the retina, we believe it may still cause mechanical stress to the retina, resulting in structural damage and intraocular inflammation.


In addition, total energy and duration increase with higher refractive error and the effect of mechanical stress may be more severe in higher myopia, which has more liquification of the posterior vitreous gel."

PURPOSE: To evaluate components of the integrated ocular surface/lacrimal gland unit in a series of patients before and after undergoing bilateral laser in situ keratomileusis (LASIK).

 

DESIGN: Prospective, noncomparative case series.

 

PARTICIPANTS: Forty-eight eyes of 14 men and 34 women (age range, 26-54; mean, 39.2 years) who underwent bilateral LASIK for myopia or myopic astigmatism.

METHODS: LASIK was performed using a VISX Star Excimer Laser (Santa Clara, CA). Patients completed a questionnaire containing 11 questions that evaluated the character and severity of ocular irritation symptoms. Snellen visual acuity, tear fluorescein clearance, corneal fluorescein staining, aqueous tear production by the Schirmer 1 test, and corneal and conjunctival sensitivity were measured in each eye. Corneal surface regularity (SRI) was evaluated with the Tomey TMS-1 (Tomey, Cambridge, MA) topography instrument. Each randomly chosen eye was evaluated 1 to 2 days (T0) before LASIK and 7 days (T1), 1 (T2), 2 (T3), 6 (T4), 12 (T5), and 16 (T6) months postoperatively. A Wilcoxon test, two-tailed paired t test, Friedman test, or analysis of variance were used for statistical comparisons.

 

MAIN OUTCOME MEASURES: Components of the integrated ocular surface/lacrimal gland unit.

 

RESULTS: Both corneal and conjunctival sensitivity were noted to be significantly decreased from preoperative levels at 1week, 1 month, 12 months, and 16 months postoperatively (P < 0.0002 at each time point). Symptom severity scores were significantly increased at 1 week, 12 months, and 16 months postoperatively (P < 0.007 at all time points). The mean Schirmer 1 test scores were 24 +/- 14 mm preoperatively, and they decreased to 18 +/- 14 mm by 1 month postoperatively (P < 0.001). Tear fluorescein clearance showed a linear increase postoperatively and was significantly greater than baseline (P < 0.001) at each time point. There was a significant increase in punctate corneal fluorescein staining at 1 week postoperatively (P < 0.0001), but staining returned to baseline by 12 months. There was a statistically significant increase in SRI 1 week postoperatively (P < 0.007) with return to baseline levels by 6 months.

CONCLUSIONS: Sensory denervation of the ocular surface after bilateral LASIK disrupts ocular surface tear dynamics and causes irritation symptoms. Patients undergoing LASIK should be informed of these risks.


 - Corneal sensation remained reduced 16 months after LASIK

 - Conjunctival sensation remained reduced 16 months after LASIK

 - Tear clearance remained reduced 16 months after LASIK.

J Biomech Eng. 2006 Feb;128(1):150-60.   

Alastrue V, Calvo B, Pena E, Doblare M.  Group of Structural Mechanics and Material Modelling, Aragon Institute of Engineering Research (13A), University of Zaragoza, Spain 

The aim of refractive corneal surgery is to modify the curvature of the cornea to improve its dioptric properties. With that goal, the surgeon has to define the appropriate values of the surgical parameters in order to get the best clinical results, i.e., laser and geometric parameters such as depth and location of the incision, for each specific patient. A biomechanical study before surgery is therefore very convenient to assess quantitatively the effect of each parameter on the optical outcome. A mechanical model of the human cornea is here proposed and implemented under a finite element context to simulate the effects of some usual surgical procedures, such as photorefractive keratectomy (PRK), and limbal relaxing incisions (LRI). This model considers a nonlinear anisotropic hyperelastic behavior of the cornea that strongly depends on the physiological collagen fibril distribution. We evaluate the effect of the incision variables on the change of curvature of the cornea to correct myopia and astigmatism. The obtained results provided reasonable and useful information in the procedures analyzed. We can conclude from those results that this model reasonably approximates the corneal response to increasing pressure. We also show that tonometry measures of the IOP underpredicts its actual value after PRK or LASIK surgery.

J Cataract Refract Surg. 2005 Nov;31(11):2216-20.

 

Hamill MB, Quayle WH.

From the Cullen Eye Institute, Baylor College of Medicine, Department of Ophthalmology (Hamill), and UTMB Galveston Houston Eye Associates (Quayle), Houston, Texas, USA.

 

This report illustrates the surgical approach to and results of a complex iris reconstruction. The presentation and long-term visual and architectural results (follow-up of 4 years) of the repair of a severe anterior segment injury after entry into the anterior chamber by a microkeratome during laser in situ keratomileusis is described. The techniques used in the repair are described in detail, and a historical review of iris repair techniques is presented.

 

Article is only available if purchased. The fact this did happen due to LASIK, the industry will still deny it a risk. 

Central Corneal Thickness, and Posterior Elevation

 

 

 

Optometry & Vision Science. 82(5):428-431, May 2005.


MYROWITZ, ELLIOTT H. OD, MPH; KOUZIS, ANTHONY C. PhD; O'BRIEN, TERRENCE P. MD

http://tinyurl.com/dgugx

Abstract:
Purpose. The purpose of this study was to assess interocular corneal symmetry in average simulated keratometry, corneal thickness, and posterior corneal elevation.

Methods. This retrospective analysis included data from scanning slit topography (Orbscan II; Bausch and Lomb, Rochester, NY) on 242 eyes from 121 consecutive patients undergoing standard evaluation for consideration of elective laser vision correction. The symmetry between the right and left eye in average simulated keratometry, minimum central corneal thickness, and posterior corneal elevation was assessed by comparative data analysis.

Results. Simulated keratometry ranged from 39.9 to 48.6 D. The interocular difference in average simulated keratometry was 0.47 D (standard deviation [SD] 0.43). The interocular Pearson correlation coefficient for average simulated keratometry was 0.90 (p < 0.001). The range of minimum corneal thickness was 432 to 628 [mu]m. The interocular Pearson correlation coefficient for minimum central corneal thickness was 0.95 (p < 0.001). Right and left eye minimum corneal thickness differed by an average 8 [mu]m (SD 7). The range of posterior elevation was -4 to 54 [mu]m. The average difference in posterior corneal elevation between the right and left eye was 6 [mu]m (SD 5). The interocular Pearson correlation coefficient for posterior corneal elevation was 0.72 (p < 0.001). The average posterior elevation was 19 [mu]m (SD 11).

Conclusions. Although a wide range of values exists in simulated keratometry, minimum corneal thickness, and posterior corneal elevation, interocular symmetry in all these parameters was very high in this group of consecutive patients. Asymmetry of these interocular parameters may warrant repeat clinical testing for accuracy and may predict corneal abnormalities. Normative data on posterior cornea elevation is presented. This study points out potentially clinically important high interocular corneal symmetry data in simulated keratometry, corneal thickness, and posterior corneal elevation.

 

Am J Ophthalmol. 2004 Jul;138(1):149-51.

Brown SM, Khanani AM, McCartney DL.

Department of Ophthalmology and Visual Sciences, Texas Tech University Health Sciences Center, 3601 Fourth Street, Lubbock, TX 79430-7217, USA.

This email address is being protected from spambots. You need JavaScript enabled to view it.

 

PURPOSE: To investigate the effect of daily brimonidine tartrate 0.15% on the dark-adapted pupil diameter.

DESIGN: Observational case series.

METHOD: Ten normal volunteers administered brimonidine to their right eyes once daily. Four to six hours later, infrared pupil photographs were taken after dark adaptation. Measurements were performed at baseline; on treatment days 1, 5, 11, and 18; and on washout days 1 and 2.

RESULTS: One subject had no response. The nine responding subjects showed an average maximum antimydriatic effect of -1.63 mm (range, -0.57 mm--2.30 mm); all subjects experienced tachyphylaxis. Five subjects showed rebound mydriasis (mean maximum rebound +0.87 mm larger than baseline; range 0.50 mm-1.22 mm). The untreated pupil also responded, showing antimydriasis (two subjects), rebound mydriasis (two subjects), or paradoxical direct mydriasis (one subject).

CONCLUSIONS: Once-daily use of brimonidine tartrate to prevent dark-induced pupil dilation can lead to tachyphylaxis and rebound mydriasis.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11772601&query_hl=1&itool=pubmed_DocSum

 

Ophthalmology. 2002 Jan;109(1):175-87.

Sugar A, Rapuano CJ, Culbertson WW, Huang D, Varley GA, Agapitos PJ, de Luise VP, Koch DD.

Ophthalmic Technology Assessment Committee 2000-2001 Refractive Surgery Panel.

OBJECTIVE: This document describes laser in situ keratomileusis (LASIK) for myopia and astigmatism and examines the evidence to answer key questions about the efficacy and safety of the procedure.

METHODS: A literature search conducted for the years 1968 to 2000 retrieved 486 citations and an update search conducted in June 2001 yielded an additional 243 articles. The panel members reviewed 160 of these articles and selected 47 for the panel methodologist to review and rate according to the strength of evidence. A Level I rating is assigned to properly conducted, well-designed, randomized clinical trials; a Level II rating is assigned to well-designed cohort and case-control studies; and a Level III rating is assigned to case series and poorly designed prospective and retrospective studies, including case-control studies.

RESULTS: The assessment describes randomized controlled trials published in 1997 or later (Level I evidence) and more recent comparative and noncomparative case series (Level II and Level III evidence), focusing on results for safety and effectiveness. It is difficult to extrapolate results from these studies that are comparable to current practices with the most recent generation lasers because of the rapid evolution of LASIK technology and techniques. It is also difficult to compare studies because of variations in the range of preoperative myopia, follow-up periods, lasers, nomograms, microkeratomes and techniques, the time frame of the study, and the investigators' experience.

CONCLUSIONS: For low to moderate myopia, results from studies in the literature have shown that LASIK is effective and predictable in terms of obtaining very good to excellent uncorrected visual acuity and that it is safe in terms of minimal loss of visual acuity. For moderate to high myopia (>6.0 D), the results are more variable, given the wide range of preoperative myopia. The results are similar for treated eyes with mild to moderate degrees of astigmatism (<2.0 D). Serious adverse complications leading to significant permanent visual loss such as infections and corneal ectasia probably occur rarely in LASIK procedures;