Retinal Vessel Traits and the Development of Balance Impairment: The Canadian Longitudinal Study on Aging

The association between retinal microvascular traits and balance has not been studied. Our goal was to assess whether retinal vessel width, area, and tortuosity are associated with the development of balance impairment.

Baseline and 3-year follow-up data from the Canadian Longitudinal Study on Aging Comprehensive Cohort were analyzed. Adults aged 45 to 85 years who successfully passed a one-legged balance test at baseline were included (n = 12,929). Retinal arteriolar and venular width, area, and tortuosity were quantified using the Quantitative Analysis of Retinal Vessel Topology and Size algorithm. Multivariable logistic regression models examined the longitudinal associations between retinal vessel traits and balance impairment, adjusting for demographic, lifestyle, and health-related factors including visual acuity. Balance impairment was defined as the inability to stand unassisted on one leg for 60 seconds.

During the 3-year follow-up, 2378 participants developed balance impairment. Greater retinal venular width was associated with a higher adjusted odds of incident balance impairment (odds ratio, 1.61; 95% confidence interval, 1.01-2.58). A greater retinal arteriolar area was associated with a lower adjusted odds of incident balance impairment (odds ratio, 0.82; 95% confidence interval, 0.68-0.99). Retinal arteriolar and venular tortuosity were not associated with balance (odds ratio, 0.89; 95% confidence interval, 0.74-1.07; and odds ratio, 1.20; 95% confidence interval, 0.88-1.63, respectively).

Retinal venular widening and reduced arteriolar area are associated with developing balance impairment despite adjustment for visual acuity, cardiovascular disease, and cognition. These novel results should be confirmed and the biological mechanism clarified.