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.