Abstract
Purpose :
Myopia increased in children during COVID-19 pandemic. There is limited evidence as to whether myopia development was reversed or aggrandized after the lockdown. We aimed to determine the prevalence of myopia and its associated factors before, during, and after COVID-19 restrictions.
Methods :
This is a population-based, repeated cross-sectional study. Participants from the Hong Kong Children Eye Study (HKCES) between 2015 to 2021 were included as the pre-COVID-19 cohort (before 2019), the COVID-19-Restrictions cohort (in 2020), and the post-COVID-19-Restrictions cohort (in 2021). All the children received cycloplegic autorefraction and axial length (AL). Data about the children’s lifestyle included the time spent on outdoor activities, near work, and screen time. The prevalence of myopia, changes in lifestyle and the associated factors over 7 years were assessed.
Results :
Totally 20,527 children aged 6 to 8 years were included in this study, with 10,828 (52.8%) boys and 9,699 girls (47.2%), mean age 7.33±0.89 years. The prevalence of myopia from 2015 to 2019 was stable (from 23.5 to 24.9%, P=0.90), but was increased to 28.8% (P<0.001) in 2020 and 36.2% (P<0.001) in 2021. The increasing trend was similar for mean SE and AL. The mean time spent on outdoor activities was much lower in 2020 (0.85 hours/day, P<0.001) and in 2021 (1.26 hours/day, P<0.001), compared to the pre-COVID-19 period (between 1.40 to 1.46 hours/day from 2015 to 2019). The trend was reversed for mean total near work time and screen time. Myopia prevalence increased with the COVID-19 pandemic (OR=1.78, P<0.001), younger age (OR=1.84, P<0.001), low family income (OR=1.05, P=0.04), male sex (OR=1.12, P=0.006), and parental myopia (OR=1.61, P<0.001). Myopic SE shit was observed in children of family income <HK$25,000 (P<0.001) and HK$25,000 to HK$49,999 (P=0.03), but not in the group of family income ≥ HK$50,000 (P=0.09).
Conclusions :
After the COVID-19 restrictions were lifted in 2021, myopia prevalence was higher than pre-COVID-19 time. Time spent outdoors, near work time, and screen time did not return to pre-COVID-19 levels. Younger children and children from low-income families were at a higher risk of myopia during the pandemic. It is recommended that increasing time outdoors and decreasing screen time be advocated for these groups of children in particular.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.