Diabetes May Modulate the Association Between Age and Optical Coherence Tomography Angiography Parameters: A Serial, Cross-Sectional Study

Purpose: We investigated the association between age and retinal microvasculature parameters as measured by optical coherence tomography angiography (OCTA) and the modifying effect of diabetes status on this association. Methods: In this serial, cross-sectional study, 3 × 3 mm2 macular OCTA images were obtained from healthy adults and adults with diabetes mellitus (DM) with no diabetic retinopathy (DR) or with mild non-proliferative DR (NPDR). The parameters analyzed included foveal avascular zone (FAZ) area and perimeter, vessel density (VD), vessel length density (VLD), and flow index (FI) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP). The associations between OCTA parameters and age were explored using multivariable linear regression models. Results: For the included 1855 patients (1855 eyes) (49% male; mean age: 55 years), the results were as follows: no diabetes (N = 217), DM no DR (N = 1352), and mild NPDR (N = 286). Increasing age was significantly associated with decreased SCP and DCP VD and VLD in the diabetic and non-diabetic groups. The slope of association between SCP and DCP FI and age in the diabetic patients was significantly different than that in the control patients. Conclusions: The strength of the association between aging and OCTA parameters differed significantly between the controls and those with early retinopathy, pointing to a potentially altered retinal vascular homeostasis secondary to diabetic pathophysiology. This finding offers insight into the early pathological biomarkers of DR and may guide early DR management for patients based on personalized risk scores.