Lockdowns that were enacted during the COVID pandemic have meant less time spent outdoors for thousands of children, which raised concerns about whether home confinement has worsened the burden of myopia. A school-based cross-sectional study in China, presented recently at the ARVO annual meeting, investigated the refractive change and prevalence of myopia for school-aged kids.

A total of 123,535 children ages six to 13 were screened between 2015 and 2020, which included a total of 194,904 tests from 389,808 eyes. Non-cycloplegic refraction and spherical equivalent refraction were recorded for each child and the prevalence of myopia for each age group in each year was calculated. The mean spherical equivalent and prevalence of myopia were compared between 2020 (after home confinement) and the previous five years for each age group.

A substantial myopic shift (around -0.3D) was found in the 2020 school-based screenings when compared with previous years for school-aged children at ages six (-0.32D), seven (-0.28D) and eight (-0.29D). The prevalence of myopia in the 2020 tests was much higher than the highest rates from 2015 to 2019 for children at age six (21.5% vs. 5.7%), seven (26.2% vs. 16.2%) and eight (37.2% vs. 27.7%). The differences in spherical equivalent and prevalence of myopia between 2020 and previous years were minimal in children ages nine to 13.

“This study tells us that the home confinement due to COVID-19 was associated with a significant myopic shift for children,” the authors concluded in their presentation. “Younger children (ages six to eight) are more sensitive to environmental changes to develop myopia than older children, given that the younger children are in a critical period for the development of myopia.”

Qian X, Li Y, Musch DC, et al. The critical period of myopia, insight from the myopic shift in school age children after COVID-19 home confinement. ARVO 2021 annual conference.