EXCIMER-LASER IN-SITU KERATOMILEUSIS UNDER A CORNEAL FLAP FOR MYOPIA OF 2 TO 20 DIOPTERS

PURPOSE: We studied the efficacy and safety of a recent technique of k eratomileusis for myopia, excimer laser in situ keratomileusis. METHOD S: We studied retrospectively 88 eyes of 63 patients who received exci mer laser in situ keratomileusis with the Chiron Automated Corneal Sha per and the Summit OmniMed laser under a hinged corneal flap without s utures. RESULTS: Mean follow-up was 5.2 months, Mean spherical equival ent of the manifest refraction before surgery was -8.24 diopters (rang e, -2.00 to -20.00 diopters), Mean spherical equivalent refraction aft er surgery was +0.22 +/- 1.42 diopters, Of 40 eyes with a baseline ref raction from -2.00 to -6.00 diopters, 25 eyes (63%) had refraction wit hin +/-0.50 diopter of emmetropia, and 37 eyes (93%) had refraction wi thin +/-1.00 diopter, In eyes with baseline refraction of -6.12 to -12 .00 diopters, postoperative refraction was within +/-1.00 diopter in 1 9 (65%) of 29 eyes, In eyes with baseline refraction of -12.10 to -20. 00 diopters, postoperative refraction was +/-1.00 diopter in eight (43 %) of 19 eyes, Overall, 64 (72.8%) of 88 eyes had a refraction within +/-1.00 diopter after surgery, Between three weeks and five months aft er surgery the change in the mean spherical equivalent refraction was -0.61 diopter in the myopic direction, Uncorrected visual acuity after surgery was 20/20 or better in 31 eyes (36%) and 20/40 or better in 6 1 eyes (71%), Three eyes (3.6%) lost two lines or more of spectacle-co rrected visual acuity, two from progressive myopic maculopathy and one from irregular astigmatism. No eyes had vision-threatening complicati ons. CONCLUSION: Excimer laser in situ keratomileusis under a corneal flap can be an effective method of reducing myopia between -2.00 and - 20.00 diopters, with minimal complications, Current surgical algorithm s need modification to improve predictability of outcome, Stability of refraction after surgery requires further study.