Evaluation of the long-term effects of photorefractive keratectomy correction for myopia in China

PURPOSE: To evaluate the long-term effects of photorefractive keratectomy (PRK) correction for myopia in China. METHODS: A comprehensive literature research was conducted in 2 Chinese databases and PubMed. Statistical analysis was performed using the RevMan 4.2 software. RESULTS: Seven prospective studies involving 2,796 eyes were included. The follow-up period was 5 to 11 years. Meta-analysis showed efficacies in low to moderate myopia that surpassed those in high myopia, and pooled odds ratios were 9.14 (95% confidence interval [CI] 4.37-19.11) in the proportion of eyes with uncorrected visual acuity (UCVA)=20/20 and 5.61 (95% CI 3.97-7.93) in the proportion of eyes with UCVA=20/40. More than 10 years post operation, 82.0% had 20/20 or better UCVA and 96.1% had 20/40 or better in the =-6.00 D myopia group. Among patients with >-6.00 D myopia, 31.7% had 20/20 or better UCVA and 80.4% had 20/40 or better. Moreover, 82.1% and 46.4% of the treated eyes were within ±1.0 D of target refraction in the low to moderate myopia and high myopia group, respectively. About 1.4%-3.5% of eyes lost =2 lines of best spectacle-corrected visual acuity, and 0.6%-4.1% of eyes had grade 1 corneal haze. CONCLUSIONS: Photorefractive keratectomy for myopia is an effective and safe procedure for the long term in China. The efficacy and predictability of PRK in low to moderate myopia are better than in high myopia.