PREVALENCE AND TIME TRENDS OF MYOPIA IN CHILDREN AND ADOLESCENTS IN CHINA A Systemic Review and Meta-Analysis

Purpose: To estimate prevalence, associated factors, and time trends of myopia in Chinese children and adolescents. Methods: We searched PubMed, EMBASE, and Web of Science for studies examining the prevalence of myopia in children and adolescents aged 3 years to 19 years in China before October 2018. We pooled the prevalence and associated factors for myopia and estimated time trends. Results: In 22 eligible studies including 192,569 individuals, the pooled prevalence (95% confidence interval [CI]) of myopia and high myopia in the study period from 1998 to 2016 was 37.7% (95% CI: 23.5-52.0%) and 3.1% (95% CI: 1.2-5.0%), respectively, with higher odds for girls than boys (myopia: odds ratio: 1.29; 95% CI: 1.14-1.46; P < 0.001; high myopia: odds ratio: 1.37; 95% CI: 1.05-1.78; P = 0.02) and with higher prevalences for urban areas than rural regions (myopia: 48.8% [95% CI: 32.3-65.3] vs. 31.9% [95% CI: 20.4-43.3; P < 0.001]). The pooled prevalence of myopia and high myopia increased from 4.7% (95% CI: 2.5-6.9) and 0.2% (95% CI: 0.0-0.5), respectively, in <7-years-olds to 56.2% (95% CI: 29.8-82.5) and 15.1% (95% CI: 6.4-23.8), respectively, in 16- to 18-year-olds. Myopic refractive error increased with older age (P < 0.001), female gender (P < 0.001), and study year (P = 0.003). Studies performed after 2013 showed a prevalence of myopia and high myopia in the 16- to 18-year-olds of 84.8% (95% CI: 84.4-85.2%) and 19.3% (95% CI: 18.6-20.2%), respectively. Assuming a further linear relationship with the study year, myopia prevalence in 2050 among children and adolescents aged 3 years to 19 years would be estimated to be about 84%. Conclusion: The marked rise in high myopia prevalence among adolescents in China may be of importance for high myopia as risk factor for irreversible vision loss in Chinese adults in the future.