Abstract
Abstract: :
Purpose: To report the incidence and outcomes of diffuse lamellar keratitis (DLK) after LASIK and analyze potential causative factors. Methods: Retrospective review of LASIK cases performed between May 1995 and October 2002. Factors assessed included gender, procedure (primary or enhancement), previous or subsequent LASIK, involved eye, and instrument sterilization protocol utilized. Outcomes measured included resolution of DLK and final visual acuity. Results: A total of 15119 LASIK cases were analyzed, including 11232 primary procedures and 3887 enhancements. There were 61 DLK cases, including 33 (0.46%) in males and 26 (0.32%) in females (p = 0.191), and 54 (0.48%) in primary cases, and 7 (0.18%) in enhancements (p = 0.008). There were 28 cases of bilateral LASIK with unilateral DLK; 15 cases developed DLK in the first treated eye and 13 cases developed LDK in the second eye. Seven cases of DLK occurred in eyes with previous uneventful LASIK, and 13 eyes with DLK had subsequent uneventful LASIK. Three sterilization protocols were utilized: 1) steam autoclave without reservoir, 2) cassette autoclave with reservoir, 3) steam autoclave without reservoir and new instrument cleaner. There were 11 (0.13%) DLK cases with protocol 1, 47 (0.94%) DLK cases with protocol 2, and 3 (0.17%) DLK cases with protocol 3. The difference in the incidence of DLK between protocol 1 and 3 was not significant (p = 0.72), but protocol 1 and 3 had significantly lower DLK rates than protocol 2 (p<0.001). All cases had full resolution of DLK without permanent scarring after treatment. Of the 59 cases with adequate follow-up data, 10 cases (16.9%) lost one line of BSCVA, 25 (42.4%) had no change, and 24 (40.7%) gained one or more lines of BSCVA postoperatively. Most cases (91.5%) had a final manifest refraction within 0.5 D of emmetropia. Conclusions: DLK is a nonspecific inflammatory response to multiple stimuli, with both sporadic and clustered occurrence. The occurrence of DLK is not due to individual variation in the inflammatory response. Although significantly more cases occurred after primary LASIK, DLK cannot be attributed solely to the microkeratome or to material deposited by the microkeratome. Sterilizers with reservoirs and instrument cleaners may play a role in the development of DLK. With appropriate treatment, outcomes after the development DLK are comparable to uncomplicated LASIK cases.
Keywords: refractive surgery: complications • refractive surgery: LASIK