A new study has shown that children who spend more time in front of television and computer screens and less in outdoor physical activity have narrower blood vessels in their eyes. In adults, constricted blood vessels in the eyes have been linked to an increased risk of cardiovascular disease.
For the study, researchers from Australia studied 1,492 6-year-olds randomly selected from 34 schools in Sydney. The children’s parents completed questionnaires asking how much time their children spent in physical activities and how much time they spent in front of a TV or computer. Then the researchers examined the children’s eyes. After adjusting for a variety of health factors, they found that blood vessels in the eyes of children who watched the most TV were slightly smaller in diameter than those in children who watched the least amount. The results for physical activity were similar: the eyes of children who exercised the least had the narrowest blood vessels. The reason is unclear.
Dr. Paul Mitchell, a professor of ophthalmology at the University of Sydney and lead author of the study said, “We don’t know what it means in children…We have to follow them for much longer.” Dr. Bamini Gopinat, a researcher at the University of Sydney, said, “Changes to the retinal vessels give a good idea of what is going on in the rest of the body, particularly the heart. In adults, we’ve found that narrower retinal arteries signal increased risk of hypertension (high blood pressure) and heart disease”.
Dr. Audrina Berrocal of the University of Miani Bascom Palmer Eye Institute said that parents should be aware that it isn’t the amount of TV or computer time that is affecting the size of the vessels. Instead, she said “it is the lack of exercise” their sedentary lifestyle leads to that causes these negative health effects at such a young age.
The study was published on Thursday in the journal Arteriosclerosis, Thrombosis and Vascular Biology.
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