Retinal microvascular dysfunction in hypercholesterolemia

Background Hypercholesterolemia is one of the most important contributors to atherosclerosis. Whether hypercholesterolemia also affects the retinal microcirculation is unclear. Objective The goal of our study was to assess the association of cholesterol levels with retinal microvascular function using dynamic and static retinal vessel analysis (RVA) in a primary prevention setting. Methods This cross-sectional, observational study prospectively recruited 67 patients with hypercholesterolemia without known cardiovascular disease (mean age 64.4 ± 10.4 years; 45% female) and 78 healthy controls (mean age 61.8 ± 11.2 years; 45% female). The primary end point of the study was flicker-induced dilatation of retinal arterioles (FID art ) with secondary exploratory outcomes including venular FID (FID ven ), arteriovenous ratio, flow-mediated dilatation and arterial stiffness as measured with augmentation index and pulse wave velocity. Multiple regression analysis was performed to study the association of cholesterol levels with retinal microvascular function. Results FID art was significantly impaired in patients with hypercholesterolemia compared with healthy controls (mean FID art 2.1 ± 1.8 vs 3.1 ± 1.8%, P  = .001). This association remained when analysis was restricted to dyslipidemic patients without coexisting hypertension or lipid-lowering therapy. No significant differences remained for FID ven , flow-mediated dilatation, arteriovenous ratio, or arterial stiffness between the groups. Low-density lipoprotein, but not high-density lipoprotein, cholesterol was a significant negative predictor of FID art in multiple regression analysis. Conclusion Hypercholesterolemia is associated with significant retinal microvascular dysfunction as evidenced by a reduction in flicker-induced dilatation of retinal arterioles. Dynamic RVA may be a promising method for the study of retinal microvascular dysfunction in populations at elevated cardiovascular risk.