The prevalence of myopia remains stable under tighter COVID-19 social restriction in preschoolers receiving a school-based eyecare program.

ABSTRACT

PURPOSE: This study investigated the impact of different levels of COVID-19 social restrictions (social distancing in 2020, large-scale home confinement in 2021) on myopia prevalence and behaviours in a preschool population with school-based eyecare programme. METHODS: Repeated cross-sectional surveys were conducted between August and December in 2019, 2020 and 2021. Children aged 5-6 years received ocular examinations, and questionnaires were answered by caregivers before the day of the examination. The main outcome measures were the changes in after-school time spent on homework, screen-based devices and outdoors. Secondary outcome was the change in myopia prevalence (spherical equivalent [SE] ≤ -0.5 D in either eye after cycloplegia). RESULTS: A total of 9997 preschoolers were included in the analysis. Under tighter restrictions, more preschoolers spent ≥1 h/day on screen-based devices (42.8% in 2019, 45.2% in 2020, 48.9% in 2021, p < 0.001), and fewer preschoolers spent ≥30 min/day on after-school outdoor activities (49.5% in 2019, 46.0% in 2020, 41.0% in 2021, p < 0.001) on weekdays. A similar trend was found on weekends. While more preschoolers spent ≥2 h/day on screen-based devices (35.3% in 2019, 38.5% in 2020, 43.0% in 2021, p < 0.001), fewer preschoolers spent ≥2 h/day on outdoor activities (41.7% in 2019, 41.7% in 2020, 34.0% in 2021, p < 0.001). The mean SE and myopia prevalence were stable (9.1% in 2019, 10.3% in 2020, 9.4% in 2021, p = 0.707). CONCLUSION: Our study showed dose-dependent effect of social restrictions on near-work and outdoor behaviours at home. The prevalence of myopia did not increase significantly with short-term cessation of school-based eyecare programmes.