Abstract / Summary
Background Severe carotid artery stenosis or occlusion (CASO) is associated with white matter injury and cognitive impairment, but markers of accompanying microvascular dysfunction remain incompletely characterized. We investigated the relationships among retinal microvascular abnormalities on optical coherence tomography angiography, white matter hyperintensities (WMH), and cognitive impairment in severe unilateral CASO. Methods In this multicenter cross‐sectional study, 860 participants were included: 566 patients with severe unilateral CASO without acute cerebral infarction and 294 control participants with similar age and sex distributions. All participants underwent multimodal imaging, including automated WMH segmentation on brain magnetic resonance imaging and macular optical coherence tomography angiography. Cognitive function was assessed using the Montreal Cognitive Assessment. Results Compared with controls, patients with CASO showed lower vessel length density across retinal layers and greater WMH burden. Within the group with CASO , the retina ipsilateral to the stenosis showed lower vessel length density and greater vessel dilation, paralleling the greater burden of deep WMH in the ipsilateral hemisphere (all adjusted P <0.05). Retinal microvascular abnormalities and greater WMH burden were both associated with worse concurrent cognitive performance. Adding optical coherence tomography angiography metrics to clinical and WMH ‐based models provided modest additional discrimination for identifying concurrent cognitive impairment in internal cross‐validation, increasing the area under the curve from 0.652 to 0.695 ( Δarea under the curve , 0.043 [95% CI , 0.021–0.064]). Conclusions In severe unilateral CASO, retinal microvascular abnormalities were associated with ipsilateral white matter injury and lower cognitive performance. Optical coherence tomography angiographymetrics provided modest complementary discriminatory information beyond conventional clinical variables and WMH for identifying concurrent cognitive impairment, although external validation is required. Registration URL: https://www.chictr.org.cn/ . Unique identifier: ChiCTR2300074640.