EFFECTS OF LASER IN-SITU KERATOMILEUSIS (LASIK) ON THE CORNEAL ENDOTHELIUM

PURPOSE: To assess the effects of laser in situ keratomileusis (LASIK) on the corneal endothelium, METHODS: In a prospective study, the corn eal endothelium of 98 eyes of 65 consecutive patients (mean age, 41 ye ars; range, 22 to 66 years) was photographed before, 2 weeks after, an d 12 weeks after LASIK for the correction of 2.75 to 14.5 diopters of myopia. Theoretical ablation depths were 200 to 330 mu m below the cor neal surface. Cell density, coefficient of variation, and percent of h exagonal cells were determined using 150 to 200 cells from each image. Eighty-eight eyes (91%) of 59 patients had a history of contact lens wear, RESULTS: The mean +/- SD preoperative endothelial cell density w as 2,549 +/- 365 cells per mm(2), and the mean coefficient of variatio n was 0.35 +/- 0.06, There was no statistically significant change in the mean endothelial cell density or mean coefficient of variation of cell size at the 2 week (2,561 +/- 360 cells per mm(2) and 0.35 +/- 0. 06) or 12-week (2,541 +/- 364 cells per mm(2) and 0.35 +/- 0.05) posto perative examinations. The percent of hexagonal cells was not signific antly changed 2 weeks postoperatively; however, 12 weeks postoperative ly (P = .0413, two-tailed t test), the percent of hexagonal cells was decreased by 1%. CONCLUSIONS: Corneal endothelial cell density and mor phology were unchanged 2 and 12 weeks after LASIK for the correction o f up to 14.5 diopters of myopia. In this LASIK study, the correction o f up to 14.5 diopters of myopia appears to cause no clinically signifi cant effect on corneal endothelial cell density or morphology. (C) 199 8 by Elsevier Science Inc. All rights reserved.