A prospective observational study investigated the development and progression of myopia in children in China aged 6–8 years during the COVID-19 pandemic.

Study design

This study, evaluating distribution and changes in refraction and axial lengths among schoolchildren, had previously been initiated in November 2018. Participants included children in grades 1 and 2 from 12 randomly selected primary schools in 2 Chinese districts; children with a history of eye disease or surgery were excluded. Examinations were performed annually, and by December 2020, 3 visits had been completed. The exposure group included children in grade 1 in 2018 who were assessed in 2019 and 2020, and the nonexposure group included students in grade 2 in 2018 who were assessed in 2019 but not 2020. The changes in refraction and axial length between grades 2 and 3 in the exposure and nonexposure groups were determined.

Outcomes

The exposure group included 1054 children who underwent examinations in 2019 (pre-pandemic) and in 2020 (during the pandemic), while the nonexposure group included 1060 children who underwent examinations in 2018 and 2019 (both pre-pandemic). Prior to the pandemic, there were no differences in gender, age, mean spherical equivalent, axial length, or prevalence of refractive errors between the 2 groups. Children in the exposure group showed a 0.36-D greater myopic shift and a 0.08-mm increase in axial length compared with children in the nonexposure group. In addition, the incidence of myopia increased by 8% in the exposure group between grades 2 and 3.

Limitations

The study was limited to children in grades 2 and 3, who are between ages 6 and 8 years. Although this is an important age for myopia progression, changes in refraction may continue to occur into young adulthood.

Clinical significance

Changes in school and extracurricular activities during the COVID-19 pandemic, including reduced time outdoors and more emphasis on digital learning, may have led to increased development and progression of myopia in this group of schoolchildren. The long-term ophthalmic effects of the pandemic have yet to be fully determined.