Abstract
Purpose :
Epidemiological studies demonstrate that black populations face a higher risk of microvascular complications of DM, including diabetic retinopathy (DR), nephropathy, and amputations, compared to white populations in the US. To date, studies of diabetic ischemic insults to the retinal microvasculature have not exclusively studied black subjects with optical coherence tomography with angiography (OCTA). We used OCTA to analyze the retinal capillary vasculature and studied correlations between retinal characteristics and systemic biomarkers in black diabetic adults without DR.
Methods :
OCTA was used to image 90 eyes of 50 black subjects with DM but no DR (mean age 58.1±15.6y and average DM duration of 8.78±7.17y). Linear mixed models were used to estimate averages of macular vessel density (VD) and the area, perimeter, and acircularity index (AI) of the foveal avascular zone (FAZ) of study subjects using AngioAnalytics software. Pearson correlations were performed between OCTA characteristics and systemic disease status, smoking, renal function levels, cholesterol, and HbA1C. The University of Chicago Institutional Review Board approved the study protocol.
Results :
There were significant correlations between SCP parafoveal VD and age (r=-0.41; p=0.0001), creatinine (Cr) (r=-0.29; p=0.01), history of heart disease (r=-0.22; p=0.04), and glomerular filtration rate (r=0.24; p=0.04). In the deep capillary plexus (DCP), black subjects had an average parafoveal VD of 51.30±4.63%. There were significant correlations between DCP parafoveal VD and Cr (r=-0.22; p=0.04) and history of hyperlipidemia (r=0.22; p=0.03). Subjects had an average FAZ area of 0.33±0.13mm2, perimeter of 2.31±0.49mm, and AI of 1.16±0.08. FAZ area had significant correlations with DM duration (r=0.26; p=0.02), Cr (r=-0.30; p=0.01), and HbA1C (r=-0.31; p=0.001). Smoking pack-years was significantly correlated with FAZ perimeter (r=0.29; p=0.02) and AI (r=0.25; p=0.04).
Conclusions :
To date, this is the first study applying OCTA to characterize the retinal vasculature and its correlation with systemic biomarkers in black adults with DM but without DR. Our findings suggest that OCTA retinal microvasculature measures may serve as valuable biomarkers to track systemic vascular functioning in DM, and underscore the importance of establishing normative databases for diverse populations.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.