CHANGES IN RETINAL VESSEL DIAMETER ARE ASSOCIATED WITH CEREBRAL MICROBLEEDS IN NEUROLOGICALLY ASYMPTOMATIC INDIVIDUALS WITH TYPE 1 DIABETES

Abstract

Objective: We observed recently that a third of asymptomatic individuals with type 1 diabetes (T1D) showed signs of cerebral small-vessel disease in brain magnetic resonance imaging (MRI). Here, we aimed to explore the relationship between an easily applicable quantitative measure of retinal vessel diameters (RVD) and cerebrovascular changes in these individuals. Design and method: We included 188 individuals with type 1 diabetes and 30 healthy sex and age matched (49% males, median age 40 years) controls. Any neurological signs or symptoms were exclusion criteria. All subjects underwent a clinical and biochemical work-up, as well as brain MRI. Both retinas were phenotyped by measuring the width of all vessels located 0.5 to 1.0 disc diameters from the disc margin by a computer-assisted method (IVAN software). Summarized estimates for central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE) represented average retinal vessel diameters. The arteriole-to-venule ratio (AVR) was calculated as an additional estimate of early retinal vascular pathology. Associations between blood pressure (BP), cerebral microbleeds (CMBs), white-matter hyperintensities (Fazekas classification), and CRAE, CRVE, and AVR were assessed with non-parametric tests and linear regression models. Results: No difference in CRAE, CRVE, or AVR were found between individuals with type 1 diabetes and controls. An expected correlation between BP and CRAE (p = 0.01) was observed. Median AVR was lower among individuals with T1D and cerebral microbleeds (p = 0.02) compared to those without. A correlation between AVR and the number of CMBs (p = 0.035) was also found. Further, median CRAE was lower among those with > 10 CMBs (p = 0.039) compared to those without. We observed no correlations between RVD and white-matter hyperintensities. Conclusions: Individuals with CMBs had lower CRAE and AVR suggesting that early vascular changes in the retinal are indicative of cerebrovascular pathology in middle aged individuals with T1D.