Differences in retinal vessels support a distinct vasculopathy causing lacunar stroke

Background: Lacunar stroke is common, but the etiology of the small vessel abnormality is unknown. Retinal vessels share ontogeny, size, and physiologic characteristics with cerebral small vessels, and retinopathy is associated with stroke. We compared retinal microvessel appearance as a surrogate for cerebral small vessels in patients with lacunar and large artery cortical ischemic stroke. Methods: We prospectively recruited patients with lacunar ischemic stroke and cortical stroke controls. We took digital retinal photographs of each eye. We assessed central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) diameters and arteriovenous ratios (AVRs) using semiautomated computer software methods and quantified arteriovenous nicking and focal arteriolar narrowing. Results: Among 212 patients (105 lacunar, 107 cortical strokes) of mean age 68 years (SD 12 years), AVR was decreased (0.76 vs 0.78, p = 0.03) and CRVE was increased (44.9 pixels/218 μm vs 42.8 pixels/208 μm, p = 0.01) in lacunar patients compared with cortical patients, but CRAE did not differ (33.2 pixels/161 μm vs 33.7 pixels/163 μm, p = 0.4). On multivariable analysis, increased CRVE was associated with lacunar stroke subtype (p = 0.03) and younger age (p < 0.001) after correcting for other vascular risk factors. Arteriovenous nicking and focal arteriolar narrowing did not differ between ischemic stroke subtypes. Conclusions: Retinal venules are wider and arteriovenous ratios are smaller in patients with lacunar strokes compared with those in patients with cortical strokes.