Meta-analysis: clinical outcomes of laser-assisted subepithelial keratectomy and photorefractive keratectomy in myopia

Abstract

Purpose: To examine possible differences in clinical outcomes between laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for myopia.

Design: Systematic review and meta-analysis.

Participants: Patients from previously reported randomized controlled trials (RCTs) and comparative studies of LASEK and PRK with clinical outcomes.

Methods: A comprehensive literature search was performed using the Cochrane Collaboration methodology to identify RCTs and comparative studies comparing LASEK and PRK for myopia.

Main outcome measures: Primary outcome parameters included uncorrected visual acuity (UCVA) of 20/20 or better, manifest refractive spherical equivalent (SE) within ± 0.50 diopters (D), final refractive SE, and final UCVA of 20/40 or worse. Secondary outcome parameters included healing time of corneal epithelium, postoperative pain, and corneal haze.

Results: Twelve studies were identified and used for comparing PRK (499 eyes) with LASEK (512 eyes) for myopia. There were no significant differences in odds ratio (OR), weighted mean difference (WMD), and standardized mean difference (SMD) in the primary and secondary outcome measures. The final mean refractive SE (WMD, 0.00; 95% confidence interval [CI], -0.08 to 0.07; P = 0.95), manifest refractive SE within ± 0.50 D of the target (OR, 0.90; 95% CI, 0.63-1.29; P = 0.56), patients achieving UCVA of 20/20 or better (OR, 0.86; 95% CI, 0.61-1.20; P = 0.37), final UCVA of 20/40 or worse (OR, 1.26; 95% CI, 0.63-2.51; P = 0.52), re-epithelialization time (WMD, 0.08; 95% CI, -0.44 to 0.59; P = 0.77), and postoperative pain (SMD, 0.26; 95% CI, -0.20 to 0.72; P = 0.27) were analyzed. However, LASEK-treated eyes showed less corneal haze at 1 month after surgery (WMD, 0.25; 95% CI, 0.10-0.39; P = 0.0007) and 3 months after surgery (WMD, 0.14; 95% CI, 0.01-0.26; P = 0.03) compared with PRK. No statistically significant difference was observed between the 2 groups at 6 months after surgery (WMD, 0.14; 95% CI, -0.02 to 0.30; P = 0.08).

Conclusions: In this meta-analysis, LASEK-treated eyes had no significant benefits over PRK-treated ones with regard to clinical outcomes. Less corneal haze was observed in LASEK-treated eyes at 1 to 3 months after surgery.