Influence of Chinese eye exercises on myopia control in an East Asian population: a meta-analysis

Abstract

Objective: The rates of myopia (−0.50 diopter), and high myopia (≥ −6.0 diopter) have been increasing in East Asian populations; the reasons for which may include the combinations of genetic, environment and behavioural factors. The most affected demography point to the young elite population of intellectuals produced from universities. Of the several recommendations to address the myopia epidemic, the influence of Chinese eye exercises (CEE) have been examined. However, reports have been inconsistent, prompting a meta-analysis to obtain more precise estimates. Methods: Eight articles were included in the meta-analysis where we operated on the hypothesis that CEE either increased or reduced myopia control. We compared the subjects that performed CEE against those that did not. We used and estimated odds ratios [ORs] and 95% confidence intervals (CIs) using the generic inverse variance method. Subgroup analysis involved quality (high/serious and low/non-serious) and frequency (> 5 times/week) of performing CEE comprised. Heterogeneity was subjected to outlier treatment which split the findings into pre- (PRO) and post- (PSO) outlier. The strength of evidence in our findings were based on high significance (Pa < 10-5), surviving the Bonferroni correction and homogeneity (I2 = 0%). Outcomes with these features comprised our core findings. Results: Our core findings were found in the PSO overall indicating elevated myopia control (OR 0.72, 95% CI 0.61-0.86, Pa = 0.0002) and CEE subgroups (Serious: OR 0.75, 95% CI 0.68-0.84, Pa < 10-5; Frequent: OR 0.55, 95% CI 0.45-0.68, Pa < 10-5). The low quality subgroup outcome was null in PRO (OR 0.97, 95% CI 0.50-1.86, Pa = 0.92) but conveyed significantly less myopia control in PSO (OR1.57, 95% CI 1.24-2.01, Pa = 0.0002). Conclusions: This meta-analysis found that CEE afforded 28% greater control of myopia. Enabled by outlier treatment, this finding was homogeneous and consistent. Subgroup effects elevated myopia control to 62% when CEE was done up to 5 times a week. Improper CEE performance implied reduced myopia control of up to 57%.