Retinal Vessel Traits and the Risk of Stroke: The Canadian Longitudinal Study on Aging.

PURPOSE: Retinal vascular changes could serve as an early, easily visible indicator of cerebrovascular health. Prior research on retinal vessel traits and stroke has predominantly focused on diameter, while vessel area and tortuosity remain underinvestigated and have yielded inconsistent results. Our goal was to examine longitudinal associations between retinal vessel traits and incident stroke. DESIGN: Prospective cohort study. PARTICIPANTS: Baseline and 6-year follow-up data from the Canadian Longitudinal Study on Aging Comprehensive Cohort (n = 30 097) were used. METHODS: A deep learning algorithm called Quantitative Analysis of Retinal Vessel Topology and Size extracted data from retinal images including arteriolar and venular diameter, area, and tortuosity. Participants were asked if a doctor had previously diagnosed them with stroke. Logistic regression was used to adjust for demographic, lifestyle, and clinical factors. Interactions with sex were also assessed. MAIN OUTCOME MEASURES: Stroke. RESULTS: Having wider arterioles at baseline was associated with lower odds of stroke development over 6 years (odds ratio [OR] = 0.84, 95% confidence interval [CI]: 0.74‑0.95). Having larger venular area was associated with a higher odds of developing stroke (OR = 1.71, 95% CI: 1.11‑2.63), whereas larger arteriolar area showed the inverse association (OR = 0.62, 95% CI: 0.44‑0.86). Statistically significant interactions were found between sex and both arteriolar and venular tortuosity (P < 0.05). CONCLUSIONS: This study confirms that retinal vessel area and stroke are associated. Vessel area and arteriolar width are associated with the development of stroke, which may help to develop stroke prediction models in the future. FINANCIAL DISCLOSURES: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.