Assessment of early macular and peripapillary diabetic vascular changes using optical coherence tomography angiography

Purpose The aim of this study was to evaluate the macular and peripapillary vascular parameters in diabetic patients using optical coherence tomography angiography (OCTA). Patients and methods This is a prospective case–control study that included 62 participants who were classified into three groups: group I that included 23 diabetic patients with no clinical signs of diabetic retinopathy, group II that included 19 patients with mild nonproliferative diabetic retinopathy, and group III that included 20 healthy participants as a control group. Optical coherence tomography 6×6 mm disc map, optical coherence tomography angiography radial peripapillary capillary plexus in 4.5×4.5 mm disc map, and superficial vascular plexus in 3×3 mm macular map were performed for all participants. The analyzed parameters included the perfusion density, vascular density, number of branches (NoB), and total branch length (tBL) that were evaluated using the ImageJ analysis software. Results The mean age of the participants was 44.85±13.88 years. The macular perfusion density and vascular density were significantly lower in group I (0.23±0.04 mm/mm 2 and 26.66±4.14%, respectively) compared to group III (0.26±0.03 mm/mm 2 and 29.75±3.84%, respectively), P value of 0.003. The mean macular NoB exhibited significant reduction in both groups I and II (1465.3±443.68 and 1420.61±262.49, respectively) compared to group III (1607.80±277.84), P value of 0.045. The macular tBL was also significantly reduced in group I (27.09±5.79 mm) and group II (26±4.35 mm) compared to the control group (36.75±11.19 mm), P value less than 0.001. The peripapillary NoB displayed statistically significant reduction in group I compared to the healthy group ( P =0.032). In addition, the peripapillary tBL was significantly reduced in groups I and II compared to group III ( P =0.007). Conclusion There were early reductions in the vascular parameters of both the superficial vascular plexus and the radial peripapillary capillary plexus in the diabetic patients compared to the healthy controls.