Microkeratome complications of laser in situ keratomileusis.

PURPOSE To evaluate the incidence, types, and outcome of microkeratome complications that occur during laser in situ keratomileusis (LASIK). DESIGN Retrospective, noncomparative, case series. PARTICIPANTS Three thousand nine hundred ninety-eight eyes that underwent primary LASIK by four surgeons between November 1996 and August 1998 at a university-based refractive center. METHODS All cases with significant microkeratome complications leading to abandonment of the LASIK procedure were identified and reviewed. MAIN OUTCOME MEASURES Incidence of complications, change in best corrected visual acuity (BCVA), change in refractive error, and types of complication. RESULTS There were 27 complications leading to abandonment of the LASIK procedure of 3998 eyes. The overall rate of microkeratome complication was 1 in 150 (0.68%), but it was 1 in 77 (1.3%) in the surgeons' first 1000 eyes, decreasing to 1 in 250 (0.4%) in the last 1000 eyes. Of the 24 planned bilateral cases, 15 complications (63%) happened on the first operated eye. Twenty-six of 27 eyes (96%) recovered to within one line of preoperative BCVA, and one eye lost two lines. At last examination before any repeat refractive procedures, spherical equivalent manifest refraction returned to within 1 diopter (D) of its preoperative value in 18 of 19 eyes (95%), and astigmatism in 16 of 19 eyes (84%) returned to within 1 D of its preoperative value. Sixteen of 27 eyes (59%) had repeat LASIK. Two eyes had complications at repeat LASIK, one of which led to abandonment of the LASIK procedure for a second time. CONCLUSIONS There is a significant learning curve in the use of the microkeratome. If ablation is not performed, flap complications rarely lead to significant visual loss and generally do not result in a change in refractive error.