THURSDAY, April 21 (HealthDay News) -- Six-year-olds who spend the most time watching television, using a computer, or playing video games have narrower retinal arteries compared with those who spend more time engaged in physical activities, according to a study published in the May 1 issue of Arteriosclerosis, Thrombosis, and Vascular Biology.
Bamini Gopinath, Ph.D., from the University of Sydney in Australia, and colleagues investigated the correlations between physical activity (outdoor and indoor sport activities), sedentary behaviors (screen time, television [TV] viewing, playing on the computer and videogames), and retinal microvascular caliber in 1,492 6-year-old schoolchildren. Total screen time (hours/day), screen time for each sedentary activity, and physical activity were calculated from questionnaires completed by parents. Retinal vessel caliber was quantified from retinal images.
The investigators found that children who spent more time in outdoor sports (highest tertile of activity) had 2.2 µm wider mean retinal arteriolar caliber compared to those in the lowest tertile. This trend was significant, after adjusting for birth weight, axial length, age, sex, ethnicity, eye color, body mass index, and mean arterial blood pressure. A significant trend was also seen with increasing quartiles of time spent watching TV, which was correlated with narrowed average retinal arteriolar caliber by ~2.3 µm.
"These data suggest that physical activity could have a beneficial influence, whereas screen time has a potential adverse influence on retinal microvascular structure," the authors write.