Stay-at-home orders instituted during the coronavirus outbreak may be associated with a significant myopic shift for 6-to-8-year-olds, according to a recent Chinese study published in JAMA Ophthalmology.
Since December 2019, the pandemic has prompted the Chinese government to implement nationwide school closures and emergency measures to help limit the spread of coronavirus disease 2019 (COVID-19), leaving an estimated 220 million school-aged children and adolescents confined to their homes. Additionally, with in-person schooling shut down, many have been relying on online learning, increasing their exposure to screens and near-work. Researchers examining myopia have begun to examine the potential adverse effects of this prolonged indoor confinement and increased screen time. Prior research links myopia progression to insufficient time outdoors and increased duration, and intensity, of near work.
The cross-sectional study focused on children between the ages of 6 years and 13 years old from 10 elementary schools in China who had been examined via a photoscreener device during a school screening between 2015 and 2020. Test results for a total of 123,535 children. The spherical equivalent refraction was recorded for each child and the prevalence of myopia was calculated per age group.
Researchers compared the prevalence of myopia in each age group in 2020 and the prior 5 years and found a substantial shift of -0.3 D in 2020 screenings compared with previous years. The most notable differences appeared in 6-year-olds (-0.32 D), 7-year-olds (-0.28 D) and 8-year-olds (-0.29 D). Researchers also noted that the prevalence of myopia in 2020 was higher when compared with results from 2015 to 2019 in the same 3 groups, (21.5% vs 5.7%, 26.2% vs 16.2%, and 37.2% vs 27.7% respectively.
The investigators also reviewed results from 9-year-old to 13-years-old patients, but, although the shift in myopia was statistically significant, they did not consider those shifts clinically significant.“
Limitations of the research include limited data, (for instance, the photoscreener provided only noncycloplegic refraction results and information on the ocular biometry, such as axial length and cornea curvature, was not available.)
“The findings of this study suggest that home confinement during the COVID-19 pandemic was associated with a substantial myopic shift” for patients in the 6 years to 8 years age range, the study shows. The fact that this group is more impacted implies that their refractive status may be more sensitive to environmental changes than patients in older groups.
Wang J, Li Y, Musch DC, et al. Progression of myopia in school-aged children after COVID-19 home confinement. JAMA Ophthalmol. Published online January 14, 2021. doi:10.1001/jamaophthalmol.2020.6239