A Randomized Prospective Clinical Trial Comparing Laser Subepithelial Keratomileusis and Photorefractive Keratectomy

Objective: To compare laser subepithelial keratomileusis (LASEK) and photorefractive keratectomy (PRK) in different eyes of the same subjects for subjective pain level, visual acuity, and corneal epithelial healing. Design: Prospective, randomized, double-masked study. Setting: David Grant US Air Force Medical Center, Travis Air Force Base, Calif. Participants: A convenience sample of 30 active-duty military members with mild to moderate myopia. Methods: All patients had LASEK performed in one eye and PRK performed in the contralateral eye; the order of surgical procedures (ie, right eye first or left eye first) and the choice of procedures (ie, PRK in the right eye and LASEK in the left eye or LASEK in the right eye and PRK in the left eye) were determined in advance using a block randomization table. Main Outcome Measures: The primary outcome measures were subjective pain level and the rate of corneal epithelial defect recovery. Postoperatively, subjects were evaluated for their subjective pain level, visual acuity, and corneal healing (ie, epithelial defect size) during the first week and up to 30 days after undergoing the surgical procedures. Results: There were no significant differences in subjective pain levels between the LASEK- and PRK-treated eyes on postoperative days 1, 2, or 3 (P>.05) or in visual acuity on postoperative days 3, 7, or 30 (P>.05). There was a statistically significant (P<.001) smaller median epithelial defect in the LASEK-treated group (1.0 mm²) compared with the PRK-treated group (16.0 mm²) on postoperative day 1. However, by postoperative day 3, the PRK-treated group (0.0 mm²) showed significantly (P<.001) smaller epithelial defects compared with the LASEK-treated group (4.0 mm²). By postoperative day 7, epithelial defects were undetectable in any subjects in either group. Conclusions: Laser subepithelial keratomileusis and PRK have similar postoperative pain thresholds and visual acuity recordings. However, the epithelial healing pattern for LASEK and PRK differs. No additional clinical benefit is seen from the LASEK procedure relative to the PRK procedure.