Quantitative Assessment of Retinal and Choroidal Microvasculature in Asymptomatic Patients with Carotid Artery Stenosis.

Abstract

Carotid disease contributes to 15-20% of all ischemic strokes, one of the leading causes of permanent disabilities and mortality globally. With its growing prevalence and the inflicted disability rates, screening for anomalies that precede the onset of its serious complications is of crucial global significance. To assess the relationship between retinal and choroidal perfusion changes with the degree of stenosis using quantitative Swept-source optical coherence tomography angiography (SS-OCTA) in patients with internal carotid artery stenosis. A retrospective cohort study was conducted in 72 eyes with carotid stenosis. According to the degree of stenosis, the participants were divided into a healthy group (Group 1: 34 eyes), a mild-moderate stenosis group (Group 2: 22 eyes), a severe stenosis group (Group3: 16 eyes). SS-OCTA was performed to scan macular fovea. Capillary density values in the different retinal and choroidal layers were the major measurements for our study. Mean vessel density in the mid-choroid layer was significantly higher in group 2 and 3 compared with group 1. Deep choroid disclosed significantly superior vascular density values in group 3 compared to groups 2 and 1. Superficial and deep capillary plexus showed decreased vascular density values when comparing group 3 with groups 1 and 2, although they were not significant. Our report provides the first evidence that choroidal microvascular changes were correlated with severity of carotid artery stenosis. OCTA can sensitively detect subtle, early changes in the ocular blood in carotid disease representing a useful, non-invasive and objective approach to the retinal microvasculature.