PRK vs. LASIK in High Myopia: A Systematic Review and Meta-Analysis

Introduction To compare the efficacy, refractive predictability, and safety of photorefractive keratectomy (PRK) versus laser-assisted in situ keratomileusis (LASIK) in the treatment of high myopia. Unlike prior meta-analyses that evaluated mixed degrees of myopia, this study specifically focuses on high myopia (≥ –6.00 D) and incorporates more contemporary surgical techniques, providing a targeted assessment of outcomes in this higher-risk refractive population. Methods A systematic review and meta-analysis were performed according to PRISMA guidelines (PROSPERO CRD420251004602). PubMed, Web of Science, and Google Scholar were searched through March 2025 for randomized controlled trials and comparative studies that included patients with myopia ≥ −6.00 D and ≥9 months of follow-up. Outcomes included postoperative Spherical Equivalent (SE), uncorrected distance visual acuity (UDVA), refractive predictability (±0.50 D and ±1.00 D), and complications. Data were synthesized using random-effects models in RevMan 5.4. Results Eleven studies (n = 1,045 eyes) were included. Baseline SE was comparable between groups. At 1 and 12 months, no significant difference in SE was found, though PRK showed a better result at 6 months (MD = –0.29 D; P = 0.0003). Final UDVA (logMAR) did not differ (MD = 0.00; P = 0.95). LASIK achieved higher predictability, with significantly more eyes within ±0.50 D and ±1.00 D after excluding outliers. No difference was observed in the proportion of eyes reaching 20/20 vision, but LASIK was more likely to achieve 20/40 or better UDVA (OR = 0.52; P = 0.009). Complications varied: PRK was more frequently associated with corneal haze, particularly in studies that did not use intraoperative mitomycin-C (7/11 studies), whereas LASIK was more frequently associated with flap-related events. Discussion In eyes with high myopia, both PRK and LASIK demonstrated acceptable visual and refractive outcomes. Sensitivity analyses revealed that LASIK achieved superior refractive predictability within ±0.50 D and ±1.00 D, while final uncorrected visual acuity was comparable between procedures. PRK showed comparable refractive stability and remains a suitable option when corneal thickness or topography limits flap-based surgery. Compared with earlier systematic reviews, this analysis focuses specifically on high myopia and incorporates more contemporary evidence, reflecting modern refractive surgical practice. These findings support individualized procedure selection based on corneal characteristics and refractive goals. Conclusion PRK and LASIK provide comparable long-term efficacy in high myopia. LASIK offers superior refractive predictability and earlier functional vision, whereas PRK remains valuable in eyes unsuitable for LASIK, with haze risk largely mitigated by mitomycin-C.