Associations between Retinal and Choroidal Vascularization Parameters and Brachial Artery Flow-mediated Dilation in Type 2 Diabetes and Healthy Controls

Patients with type 2 Diabetes Mellitus (DM) are a group at an increased cardiovascular risk, which is associated with impaired vascular endothelial function. The aim of our study was to determine whether retinal and choroidal vascularization parameters are related to vascular endothelial function as expressed by flow-mediated vasodilatation (FMD).

Thirty-two eyes of 32 patients were included in this observational study; 15 eyes were categorized into the study group, defined as type 2 diabetic patients without diabetic retinopathy and other diabetic complications, and 17 in the healthy control group. RTVue XR Avanti optical coherent tomography angiography (angio-OCT) was used to perform OCT scans and visualize the superficial and deep retinal plexus (SCP and DCP, respectively). Using OCT image binarization, the choroidal vascularity index (CVI) was calculated. Brachial FMD was measured for each participant.

There was no difference in FMD between the DM group and healthy controls (6.64 vs 5.67, p= 0.47, respectively). A positive correlation of FMD was found with the perifoveal SCP and CVI (r=0.57 and r=0.58, respectively) in the control group and with perifoveal DCP in the study group, control group, and the whole studied population (r=0.58, r=0.89, and r=0.68, respectively). In multivariate linear regression, after adjusting for age and sex, FMD was associated with the presence of hypertension (b=-0.4) and perifoveal DCP (b=0.47).

Retinal capillary plexus density parameters are positively associated with peripheral vascular endothelial function expressed by FMD in type 2 diabetes and healthy populations.