Prevalence Trend of Myopia after Promoting Eyecare in Preschoolers: A Serial Survey in Taiwan Before and During the COVID-19 Pandemic


Purpose: To report the prevalence of preschool myopia after implementing a policy intervention promoting outdoor activities and its secular trend before and during the coronavirus disease 2019 (COVID-19) pandemic in a Taiwan preschool population.

Design: Repeated countywide population-based, cross-sectional surveys based on the Yilan Myopia Prevention and Vision Improvement Program (YMVIP).

Participants: Among 23,930 kindergarteners aged 5-6 years from seven school-year cohorts in Yilan County from 2014 through 2020, a total of 21,761 (90.9%) were finally included for analysis.

Methods: Since launching the YMVIP in August 2014, myopia prevention strategies, such as increasing outdoor activities (2 hours/weekday), have been promoted in all kindergartens, and countywide school-based eye examinations, including cycloplegic autorefraction, and caregiver-administered questionnaires have been performed annually for all participants.

Main outcome measures: The prevalence of myopia (spherical equivalent [SE] ≤-0.5D in either eye) in each of the seven school-year cohorts of preschoolers aged 5-6 years RESULTS: The prevalence of myopia continuously decreased for 2 years after implementing the YMVIP (2014 cohort: 15.5% [95% confidence interval (CI), 14.2%-16.8%]; 2015 cohort: 13.5% [95% CI, 12.3%-14.7%]; 2016 cohort: 8.4% [95% CI, 7.4%-9.4%]). Since then, the subsequent cohorts had been maximally exposed to these school-based myopia prevention strategies, and the prevalence of myopia remained relatively stable between 8.5% and 10.3%, even during the COVID-19 pandemic. Multivariable logistic regression analysis showed a dose-dependent association between the duration of exposure to preventive strategies and the prevalence of myopia (up to one-year YMVIP exposure: odds ratio [OR], 0.86; 95% CI, 0.74-0.99; up to two-year YMVIP exposure: OR, 0.56; 95% CI, 0.50-0.63) after controlling other myopiogenic factors.

Conclusions: This population-based evidence showed high prevalence of preschool myopia and an L-shaped decline after introducing strategies to promote outdoor activities in kindergartens. With undisrupted school-based preventive strategies, the prevalence of myopia can be kept stable even during the COVID-19 pandemic.

Yang YC, Hsu NW, Wang CY, Shyong MP, Tsai DC. Prevalence Trend of Myopia after Promoting Eyecare in Preschoolers: A Serial Survey in Taiwan Before and During the COVID-19 Pandemic. Ophthalmology. 2021 Aug 20:S0161-6420(21)00610-2. doi: 10.1016/j.ophtha.2021.08.013. Epub ahead of print. PMID: 34425129.