Retinal microvasculature and incident dementia over 10 years: The Three‐City‐Alienor cohort

INTRODUCTION: We explored the longitudinal relationship between retinal vascular features and dementia incidence over 10 years. METHODS: Among 584 participants from the Three‐City‐Alienor (3C‐Alienor) population‐based cohort, quantitative retinal vascular features (caliber, tortuosity, fractal dimension) were measured using semi‐automated software. Dementia was actively diagnosed over the follow‐up period. RESULTS: One hundred twenty‐eight participants (21.9%) developed dementia over a median of 7.1 years. In Cox proportional hazards models adjusted for sociodemographic characteristics, apolipoprotein E (APOE) ε4, and vascular factors, increased retinal arteriolar tortuosity was associated with all‐cause dementia (hazard ratio per standard deviation increase, 1.21; 95% confidence interval: 1.02–1.44). Wider retinal calibers and a higher venular tortuosity were associated with mixed/vascular dementia, but not Alzheimer's disease. Fractal dimensions were not associated with dementia. DISCUSSION: Changes in the retinal microvasculature were associated with dementia risk. More studies are needed to replicate these findings and determine which features might help identify persons at risk at an early stage. HIGHLIGHTS: The retinal microvasculature might reflect the brain microvasculature. We explored the association between retinal vascular features and incident dementia; 584 participants from the Three‐City‐Alienor cohort were followed‐up over 10 years. Increased arteriolar tortuosity and venular calibers were associated with dementia risk. Retinal imaging might help identify persons at risk of future dementia;