Reduced Vessel Density in the Mid-Periphery and Peripapillary Area of the Superficial Capillary Plexus in Non-Proliferative Diabetic Retinopathy.

Our aim in this study was to assess the vessel density (VD) and vessel skeleton density (VSD) in the nasal area of the superficial capillary plexus (SCP) of diabetic subjects without diabetic retinopathy (DR), or in those with a non-proliferative diabetic retinopathy (NPDR), and to evaluate the relationship between the VD and VSD and the severity of DR. In this prospective study, the VD and VSD in the SCP were measured and analyzed on 6 × 6-mm macular and nasal optical coherence tomography angiography scans. The three concentric circles of the Early Treatment of Diabetic Retinopathy Study (ETDRS) grid were used and divided into zones numbered from 1 to 9 in the macular area and from 1 to 8 in the nasal area.