Intervention Program Lowers Myopia Risk for Preschoolers
By Lynda Seminara
Selected by Stephen D. McLeod, MD
Journal Highlights
Ophthalmology, February 2022
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Although the age-specific prevalence and annual incidence of myopia are high among schoolchildren in Taiwan, little is known about myopia rates for preschoolers. In a study aimed at minimizing myopia risk, Yang et al. looked at the effects of a policy that promotes outdoor activity for this age group. Their research was conducted before and during the coronavirus pandemic. Once the intervention was introduced, the prevalence of myopia decreased continuously and did not escalate in 2020, despite the pandemic.
In August 2014, the Public Health Bureau Yilan County launched a large-scale population-based screening initiative known as the Yilan Myopia Prevention and Vision Improvement Program (YMVIP). Since then, countywide campus-based eye exams, including cycloplegic autorefraction, have been given to 5- and 6-year-olds throughout the county. Children who do not pass the eye exam are referred for further care. The intervention also includes annual caregiver surveys, public awareness strategies, and promotion of myopia-prevention measures such as limiting near work and encouraging outdoor activity for two hours a day.
For this analysis, the researchers included 21,761 kindergartners from seven school-year cohorts (2014-2020). The main outcome measure was the prevalence of myopia (spherical equivalent equal to or less than –.5 D in either eye) in each yearly cohort. The duration of exposure to myopia prevention strategies before eye screening was categorized as no exposure (2014 cohort), up to one year of exposure (2015 cohort), and up to two years of exposure (subsequent cohorts).
The investigators observed a continuous decrease in myopia prevalence in the two years following inception of the YMVIP. The prevalence rate was 15.5% in 2014, 13.5% in 2015, and 8.4% in 2016. Thereafter, it remained relatively stable (range, 8.5%-10.3%), even during the pandemic. Multivariate logistic regression analysis showed a relationship between prevention-strategy exposure and myopia prevalence (odds ratio of .86 for up to one year of YMVIP exposure and .56 for up to two years of exposure), after controlling for other myopigenic factors.
Even though myopia prevalence is high among preschoolers in Taiwan, prevention strategies such as the YMVIP program can be effective mitigators, as demonstrated in this study. An L-shaped trend toward decreased prevalence of myopia can be achieved through strategies that emphasize outdoor time and frequent school-based eye care. The authors suggest that the evidence from this study be used to support public policies to control and prevent myopia in young children.
The original article can be found here.