Increased paediatric astigmatism prevalence and severity after COVID-19

Investigators said the pandemic was associated with a 20% increase in the risk of refractive astigmatism and a 26% increase in the risk of corneal astigmatism. Image credit: ©Mangostar – stock.adobe.com

A large study performed by researchers in China and Australia found substantial increases in the prevalence and severity of refractive and corneal astigmatism, independent of myopia, in children after the COVID-19 pandemic,¹ reported first author Ka Wai Kam, MSc. He is affiliated with the Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, and the Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, both in Hong Kong.

Previous studies reported a surge in the prevalence of myopia associated with the pandemic, but the association between COVID-19 and childhood astigmatism remains unclear, the research team explained.

They conducted a population-based cross-sectional study to determine the prevalence of refractive astigmatism and corneal astigmatism in schoolchildren from 2015 to 2023 and explore the associations between the pandemic and astigmatism. The study, which stratified all the primary schools registered with the Education Bureau in Hong Kong into seven clustered regions used by Hospital Authority Services in Hong Kong, included schoolchildren 6 to 8 years of age who underwent comprehensive ocular examinations at two academic medical centers in Hong Kong from 2015 to 2023.

A total of 21,655 children were included (mean age 7.31 years), of whom 11,464 were boys (52.9%).

The investigators reported that the prevalence rate of refractive astigmatism of at least 1.0 diopter (D) was 21.4% and that of corneal astigmatism of at least 1.0 D was 59.8% in 2015. The respective percentages increased to 34.7% in 2022 to 2023.

“The pandemic was associated with a 20% increase in the risk of refractive astigmatism (odds ratio [OR], 1.20; 95% confidence interval [CI], 1.09-1.33), a 26% increase in the risk of corneal astigmatism (OR, 1.26; 95% CI, 1.15-1.38), 0.04 D in the magnitude of the refractive astigmatism (95% CI, 0.02-0.07) and 0.05 D in the magnitude of corneal astigmatism (95% CI, 0.02-0.08 (P <0 .001 for all comparisons), compared with the prepandemic period from 2015 to 2019 and after adjusting for sociodemographic factors, parental astigmatism, and child myopia,” Mr Kam and colleagues reported.

The results indicated that lifestyle changes after the pandemic were associated with an increase in the prevalence and severity of child astigmatisms that were likely associated with changes in the developing cornea.

The research team concluded, “This study found an increase in the prevalence and severity of refractive astigmatism and corneal astigmatism after the COVID-19 pandemic. Corneal changes especially along the steepest meridian may explain some of the progression of corneal astigmatism. The potential impact of higher degrees of astigmatism may warrant dedicated efforts to elucidate the relationship between environmental and/or lifestyle factors, as well as the pathophysiology of astigmatism.”

Reference

1. Kam KW, Shing E, Zhang Y, et al. Prevalence and severity of astigmatism in children after COVID-19.JAMA Ophthalmol. Published online March 20, 2025. doi:10.1001/jamaophthalmol.2025.0205