Influence of intraoperative epithelial defects on outcomes in LASIK for myopia

Internet Advance publication at ajo.com August 28, 2003. To evaluate whether intraoperative epithelial defects have an adverse effect on achieving desired refractive outcomes following laser in situ keratomileusis (LASIK) for myopia. Observational retrospective case control study. Thirty eyes that had intraoperative epithelial defects on the LASIK flap were compared with 60 randomly selected control eyes, matched for age, preoperative spherical equivalent, and preoperative cylinder, that had no intraoperative epithelial defects. Preoperative and postoperative clinical data were compared between the two groups. Statistical analyses were performed using analysis of means, analysis of variance, and the Student t test. Comparison variables included preoperative spherical equivalent, 3-month postoperative best-corrected visual acuity, attempted correction, amount of undercorrection at 3 months postoperatively, and whether LASIK enhancement was performed at 3 months postoperatively. Eyes with intraoperative epithelial defects showed more undercorrection at 3 months (P = .005), were more likely to have lost lines of visual acuity (P = .003), and underwent more enhancement procedures at 3 months (P = .004) compared with control eyes. Intraoperative epithelial defects during LASIK predispose eyes to increased wound healing, leading to myopic regression, irregular wound healing with loss of visual acuity, and increased need for enhancement procedures.