Open Collections

Abstract

Current standard magnetic resonance imaging (MRI) may not be sensitive enough to detect subtle COVID-19 related microvascular changes, and ultrahigh magnetic fields are not widely accessible to most clinical populations. This investigation was conducted to determine the utility of fundus imaging as a non-invasive, inexpensive, accessible tool for measuring retinal microvascular health and its relationship to markers of neurovascular health in individuals with and without persistent COVID. It explores the relationships between retinal measures, brain volumes, frontal white matter hyperintensity (WMH) volumes, and COVID-19 recovery group. Participants were grouped by recovery status: persistent COVID-19 (PC), PC with cognitive dysfunction (PCCD), and normal recovery. The study had four key objectives: (1) characterize demographics and retinal and brain findings in these groups, (2) examine the relationship between retinal measures and clinical factors such as age and blood pressure, (3) investigate differences in retinal measurements across recovery groups, and (4) explore correlations between retinal measures and brain volumes, including frontal WMH, and total grey and white matter volumes. Retinal images were captured using a handheld fundus camera, and features were assessed by an ophthalmologist and by the automated software AutoMorph. MRI scans were used to analyze brain structures, utilizing cortical reconstruction and volumetric segmentation and by qualitative analysis from a neuroradiologist. Retinal vessel measurements were correlated with systolic blood pressure (SBP) and/or age. Individuals in PCCD had wider arterioles, while controlling for relevant covariates, compared to other groups. Older age and wider arterioles were associated with increased frontal WMH volumes. There were no differences in frontal WMH volumes between groups. Retinal optic cup to disc ratio (CDR) was associated with changes in brain volumes, with larger CDR related to decreased percentage of white matter volume and higher percentage of grey matter volume while controlling for age. The results suggest that retinal measures can offer valuable insights into cerebral and systemic vascular health after COVID-19 infection. Additionally, there may be differences in retinal vasculature across COVID-19 recovery groups. The utility of retinal fundus imaging warrants further research to explore its full potential in monitoring cerebrovascular changes after COVID-19 infection.