An increase in myopia among children could be linked to the COVID-19 pandemic, a new study out today has suggested.
Researchers from the Department of Ophthalmology and Visual Sciences at The Chinese University of Hong Kong, Hong Kong, say the rise in cases is likely because the youngsters have spent less time outside but also increased their screen time.
Writing in the latest edition of the British Journal of Ophthalmology, they short-sightedness in children matters because it puts them at risk of developing complications that increase the risk of irreversible impaired eyesight and blindness later in life.
They studied the eyes of 1793 children, all of whom were part of the Hong Kong Children Eye Study (HKCES), an ongoing population-based study of eye conditions among six-eight-year-olds.
Of these, 709 were recruited to the study at the start of the pandemic, in December 2019 and January 2020, and were monitored for about eight months, while the remaining 1084 children had been monitored for about three years.
The children’s visual acuity was measured and they filled in questionnaires on their lifestyle, including how much time they spent outdoors and on close work, at study entry and during subsequent clinic visits.
The researchers found that about one in five (19.5%) of the children in the COVID-19 group developed short-sightedness between January and August 2020, compared with about one in three (37%) of those in the pre-COVID-19 group over the three years.
And after factoring in age, gender, length of monitoring period, parental short-sightedness, and how much time was spent outdoors and on close work, the numbers of new cases of short-sightedness were higher among children in the COVID-19 group.
The estimated one-year incidence of short-sightedness was 28%, 27%, and 26%, respectively, for children aged six, seven and eight in the COVID-19 group, compared with 17%, 16%, and 15%, respectively, for the same ages in the pre-COVID-19 group.
These changes coincided with a reduction in the time the children spent outdoors, from about one hour and 15 minutes to about 24 minutes a day and an increase in screen time from about 2.5 hours/day to about seven hours a day.
Although this is an observational study, and cannot establish cause, the research team write: “Despite all these insurmountable study limitations, our initial results still show an alarming myopia progression that warrants appropriate remedial action.”
Zhang X, Cheung SSL, Chan H-N et al. Myopia incidence and lifestyle changes among school children during the COVID-19 pandemic: a population-based prospective study. British Journal of Ophthalmology 3 August 2021; doi 10.1136/ bjophthalmol-2021-319307
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