Retinal signs and stroke - Revisiting the link between the eye and brain

Background and Purpose-The retinal and cerebral vasculature share similar anatomic, physiological, and embryologicalcharacteristics. We reviewed the literature, focusing particularly on recent population-based studies, to examine the relationship between retinal signs and stroke. Summary of Review-Hypertensive retinopathy signs ( eg, focal retinal arteriolar narrowing, arterio-venous nicking) were associated with prevalent stroke, incident stroke, and stroke mortality, independent of blood pressure and other cerebrovascular risk factors. Diabetic retinopathy signs ( eg, microaneurysms, hard exudates) were similarly associated with incident stroke and stroke mortality. Retinal arteriolar emboli were associated with stroke mortality but not incident stroke. There were fewer studies on the association of other retinal signs such as retinal vein occlusion and age-related macular degeneration with stroke, and the results were less consistent. Conclusion-Many retinal conditions are associated with stroke, reflecting possible concomitant pathophysiological processes affecting both the eye and the brain. However, the incremental value of a retinal examination for prediction of future stroke risk remains to be determined.