Exercising the eye

Findings from the Hong Kong Children Eye Study, published in Investigative Ophthalmology & Visual Science, highlight the beneficial effects of physical activity on retinal microvasculature in children, potentially offering insights into cardiovascular health monitoring. The study used retinal photographs and advanced artificial intelligence (AI) to measure the vascular health of nearly 12,000 children aged 6–8.

The researchers focused on the central retinal arteriolar equivalent (CRAE) and venular equivalent (CRVE), both indicators of retinal vessel caliber. Increased physical activity was associated with wider CRAE and narrower CRVE, which are markers of healthier vascular profiles. These findings suggest that an active lifestyle positively influences microvascular health, even at a young age.

Interestingly, the team noted some sex-specific differences in their findings. For boys, a higher ratio of physical activity to inactivity significantly widened CRAE and narrowed CRVE, while for girls, it only appeared to narrow CRVE.

The strength of the study lies in its size; however, the authors do note key limitations: i) a cross-sectional design that limited exploration of causal and temporal relationships between retinal vessel caliber, physical activity, and inactivity, ii) the use of questionnaires to understand physical activity, and iii) several unmeasured potential confounders.

Nevertheless, the authors conclude that the research “contribute[s] to the growing evidence that physical activity positively influences vascular health from a young age, thus underscoring the potential of using the retinal vasculature as a biomarker of cardiovascular health.”