Laser in situ keratomileusis for myopia and myopic astigmatism

PURPOSE: To evaluate the precision and safety of myopia and astigmatism correction using laser in situ keratomileusis (LASIK). SETTING: Augenchirurgie und Laserzentrum Hoch-Rum (Sanatorium der Kreuzsch-western), Innsbruck, Austria. METHODS: In this prospective study, LASIK was performed on 66 eyes of 39 patients with myopia ranging from 1.50 to 16.00 diopters (D). Astigmatism, ranging from -0.00 to -3.00 D, was treated simultaneously. Surgery was performed with the Chiron Keracor 117 excimer laser and the Chiron Automated Corneal Shaper microkeratome. During the 6 month follow-up, manifest refraction as well as best corrected and uncorrected visual acuities were measured; corneal topographies were produced and slitlamp biomicroscopy was performed. Changes in visual acuity and corneal topography were evaluated. RESULTS: After 6 months, mean myopia had decreased from 6.78 D +/- 3.48 (SD) to 0.40 +/- 0.98 D. Fifty-one of 63 eyes (81.0%) were within +/- 1.00 D of spherical emmetropia and 61 of 63 (96.8%) within +/- 1.00 D of cylindrical emmetropia. Uncorrected visual acuity improved in all eyes; it was 20/40 or better in 82.5% 6 months postoperatively. Best corrected visual acuity did not change in most eyes; 9.5% lost two or more Snellen lines. No central islands or corneal scars were detected postoperatively. Haze was noted in only 6 eyes (9.1%); it was transient and less than grade 1. No sight-threatening complications occurred intraoperatively. CONCLUSION: Laser in situ keratomileusis was an exact and predictable procedure for correcting low, moderate, and high myopia and myopic astigmatism.