title: Meta-analysis: clinical outcomes of laser-assisted subepithelial keratectomy and photorefractive keratectomy in myopia.
abstract: OBJECTIVE
  To examine possible differences in clinical outcomes between laser-assisted subepithelial keratectomy (LASEK) and photorefractive keratectomy (PRK) for myopia.
  
  
  METHODS
  Systematic review and meta-analysis.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
authors: Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors: Li-Quan
authors: LQ
authors: Zhao
authors: Rui-Li
authors: RL
authors: Wei
authors: Jin-Wei
authors: JW
authors: Cheng
authors: You
authors: Y
authors: Li
authors: Ji-Ping
authors: JP
authors: Cai
authors: Xiao-Ye
authors: XY
authors: Ma
mesh_terms: D003318:Corneal Opacity / Q000503:physiopathology; D019573:Epithelium, Corneal / Q000502:physiology; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D016017:Odds Ratio; D010149:Postoperative Pain; D018903:Photorefractive Keratectomy; D016032:Randomized Controlled Trials as Topic; D012029:Refraction, Ocular / Q000502:physiology; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014945:Wound Healing / Q000502:physiology