Under-correction or full correction of myopia? A meta-analysis

PURPOSE: To compare the effect of full-correction versus under-correction on myopia progression. METHODS: A literature search was performed in PubMed, Scopus, Science Direct, Ovid, Web of Science and Cochrane library. Methodological quality assessment of the literature was evaluated according to the Critical Appraisal Skills Program. Statistical analysis was performed using Comprehensive Meta-Analysis (version 2, Biostat Inc., USA). RESULTS: The present meta-analysis included six studies (two randomized controlled trials [RCTs] and four non-RCTs) with 695 subjects (full-correction group, n = 371; under-correction group, n = 324) aged 6 to 33 years. Using cycloplegic refraction, the pooled difference in mean of myopia progression was – 0.179 D [lower and higher limits: −0.383, 0.025], which was higher but not in full correction group as compared to under correction group (p = 0.085). Regarding studies using non-cycloplegic subjective refraction according to maximum plus for maximum visual acuity, the pooled difference in myopia progression was 0.128 D [lower and higher limits: −0.057, 0.312] higher in under-correction group compared with full-correction group (p = 0.175). Although, difference in myopia progression did not reach significant level in either cycloplegic or non-cycloplegic refraction. CONCLUSIONS: Our findings suggest that, myopic eyes which are fully corrected with non-cycloplegic refraction with maximum plus sphere, are less prone to myopia progression, in comparison to those which were under corrected. However, regarding cycloplegic refraction, further studies are needed to better understand these trends.