By comparing several years of annual vision screening data from school children in Feicheng, a team of researchers, including UM Professor of Ophthalmology and Epidemiology David Musch, found dramatic increases in the prevalence of myopia immediately following mandatory home-confinement periods in the city.
The team’s work, initially highlighted in JAMA Ophthalmology in 2021, was the subject of another article this February in the same journal, a new study encompassing a longer-range data set and leaving little room for doubt about the connection between the home-confinement and myopia prevalence.
“This ecologic study was built on the uniqueness of how China handled the COVID pandemic,” Musch said. “The children could not go outside except for very prescribed periods of time. And education was conducted via near-vision screen time. Both factors are known contributors to myopia development, and so inspecting vision screening results obtained before and after the quarantine period led to some pretty striking findings.”
Feicheng is a city of a little less than 1 million people about 350 kilometers south of Beijing. Typically, elementary school children received annual vision screenings. But screenings weren’t conducted in the early part of 2020 when schools were closed due the COVID-19 pandemic.
The study team, which included colleagues at Emory University, in Atlanta, and Tianjin Medical University and Eye Hospital, based their findings on the annual screening data obtained from a total of 325,443 children over a six-year period beginning in 2015, continuing through the COVID-19 closures, and after students returned to school.
The work not only sheds light on how myopia prevalence rises across children of increasing age, but also has implications for how lifestyle and activity habits can influence the condition; the city’s quarantine periods substantially limited time outdoors, coupled with an increase in screen time associated with remote e-learning.
The rise was especially dramatic among 6-year-old children, for whom myopia rates were 3.8 times higher in the post-COVID screenings compared to the same age group in the pre-COVID years. By 2021, after the quarantine period had elapsed, annual screening revealed the myopia rate for children in this age group had returned to pre-pandemic levels.
“The implications are pretty important and could influence public health leaders to advise that schools and parents become more attentive to providing a healthy balance between the amount of time children spend that involves near-vision and outdoor activities,” Musch said.