One-year Outcomes of Epi-LASIK for Myopia

Abstract

To evaluate the early clinical outcomes of epi-LASIK for myopia. This study comprised 302 eyes of 162 patients. Epi-LASIK was performed with an automatically rotational epikeratome (KM-5000D). Epithelial separation was achieved mechanically without the use of alcohol. After laser ablation, the epithelial sheet was repositioned and a therapeutic contact lens was applied to the cornea immediately for 3 to 5 days. Postoperative visual acuity, symptoms, epithelial sheet, contrast sensitivity, wavefront aberration, and haze formation were evaluated 3, 6, and 12 months postoperatively. Of the 302 eyes, 72 eyes (42 patients) with a mean spherical equivalent refraction of -9.13 +/- 4.23 diopters (D) (range: -1.25 to -19.0 D) had > 1-year follow-up. One eye failed to make the epithelial sheet because of the narrow palpebral fissure. An integrated epithelial sheet with a diameter of 8 to 9 mm was made in 289 (95.7%) eyes, leaving a superior hinge of approximately 2 to 4 mm. In 1 eye, stromal tissue remained in the epithelial sheet. Free epithelial flaps were made in 12 (4%) eyes. Mild discomfort was reported by 150 patients (282 eyes, 93.4%). Twelve patients (20 eyes, 6.6%) reported moderate symptoms. At 1 day postoperatively, corneal epithelium was almost transparent or had mild focal edema in 288 (95.4%) eyes; moderate edema was reported in 14 (4.6%) eyes. At 1 year postoperatively, spherical equivalent refraction of 60 (83.3%) eyes was within +/- 1.0 D of attempted refraction. Grade 0.5 haze was found in 2 eyes; all other eyes had no haze. No eye lost any lines of best spectacle-corrected visual acuity (BSCVA), whereas 12 (16.7%) of 72 eyes gained one or two lines of BSCVA. Contrast sensitivity decreased 1 month postoperatively and was restored to preoperative levels in eyes with preoperative spherical equivalent refraction < -10.0 D. Higher order aberration increased significantly postoperatively. Epi-LASIK is a safe and efficient method to correct myopia with the advantage that it has only mild symptoms and mild haze. A larger study with longer follow-up is needed to determine its long-term clinical outcomes.