Retinal vessel diameter reflects altered resting-state fMRI connectivity and cognitive performance: A community-based study.

This study investigated the relationship between fundus microvascular characteristics and the nodal local efficiency (Nle) of brain functional connectivity (FC), as well as their association with cognitive performance in a community-based cohort. A total of 1532 participants from Lishui City, China, were enrolled between May 2017 and September 2019 as part of the polyvascular evaluation for cognitive impairment and vascular events (PRECISE) study. Cognitive performance was assessed using the Montreal Cognitive Assessment-Beijing (MoCA-Beijing), and Nle was derived from resting-state functional magnetic resonance imaging (rs-fMRI). Fundus photography of the left eye was performed to measure microvascular features, including the central retinal arterial equivalent (CRAE), central retinal vein equivalent (CRVE), and their ratio (AVR). Correlations between fundus microvascular indices, cognitive function scores, and brain FC were analyzed. Notably, a wider CRVE was significantly associated with poorer naming scores on cognitive assessments. Several key brain regions, including the left orbital gyrus, right inferior temporal gyrus, left parahippocampal gyrus, bilateral posterior hippocampus, left fusiform gyrus, and left inferior parietal lobule, demonstrated significant correlations between fundus microvascular indices and brain FC. These regions played a crucial role in cognitive function and neural network connectivity. Overall, fundus microvascular characteristics were correlated with the indicators of brain FC related to cognitive function. Our findings suggest that fundus microvascular characteristics may serve as a potential non-invasive biomarker for detecting brain functional alterations linked to cognitive dysfunction in elderly populations.