Retinal Vessel Analysis shows distinct endothelial dysfunction in hospitalizedCOVID-19 patients (The CoViThel Study) Measuring endothelial dysfunctionin COVID-19 with RVA

Aims: Patients with SARS-CoV-2 infection exhibited a heterogenous disease course, ranging from asymptomatic or mild to critical ill patients. One factor contributing to the severity, is endothelial dysfunction, which is difficult to quantify in clinical routine. We hypothesized that retinal vessels may serve as a promising target to analyze endothelial dysfunction in these patients. Methods and Results: 90 COVID-19 patients were consecutively included in the study and received an examination of retinal vessels using Static Vessel Analyzer (SVA) and Dynamic Vessel Analyzer (DVA 3). Matched healthy individuals were used as a control group in this prospective cohort study. After matching there was no difference in age and gender between the two groups. We found a higher BMI in the COVID-19 group. SVA showed both wider arterial (209.1 MU (SD 18.6) vs. 181.3 MU (SD 16.4), p < 0.001) and venular (256.5 MU (SD 20.9) vs 210.8 MU (SD 24.7), p < 0.05) diameters in the COVID-19 group (p < 0.001). DSVA showed both less arterial dilatation (2.35% (SD 1.70) vs. 3.70 % (SD 1.69) and arterial constriction (-1.02% (SD 1.024) vs. -1.41% (SD 1,43) in COVID-19 patients compared to healthy controls. Subgroup analysis showed a continuous decline in arterial dilatation (p < 0.01) and constriction (p <0.05) with increasing disease severity Conclusion: Parameters of retinal microcirculation are impaired in COVID-19 patients as examined by Static and Dynamic Vessel analyzer. Further studies including longitudinal analysis are needed to further investigate diagnostic potential of the examination.