Aims: To evaluate superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) perfusion in macular and near/mid periphery regions in diabetic patients using widefield swept-source optical coherence tomography angiography (WSS-OCTA).
Methods: Ninety-four diabetic patients (94 eyes) classified as diabetics without diabetic retinopathy (no DR) (25 eyes), mild DR (23 eyes), moderate/severe DR (26 eyes), proliferative DR (20 eyes) and a control group of 25 healthy subjects (25 eyes) were imaged with the WSS-OCTA system (PLEX Elite 9000, Carl Zeiss Meditec Inc., Dublin, CA, USA). Quantitative analysis was performed in the macular and peripheral regions. The main outcome measures were perfusion density (PD) and vessel length density of SCP, DCP and CC.
Results: Peripheral retina (all sectors) showed lower SCP and DCP PD compared to the macular region (p < 0.001). In diabetics without DR and DR in different stages, SCP and DCP PD significantly decreased at advancing stages of DR (p < 0.001). At DCP level, central PD was significantly directly related to peripheral PD (superior, R = 0.682 and 0.479; temporal, R = 0.918 and 0.554; inferior, R = 0.711). A good sensitivity and an excellent specificity were found in terms of prediction of disease worsening, especially for central and temporal sectors in all plexuses and for all sectors both central and peripheral of DCP.
Conclusions: The widefield OCTA is useful for the study of central and peripheral retina in diabetic patients with or without diabetic retinopathy, assessing good correlation between central and peripheral retina.
Keywords: Diabetic retinopathy; Perfusion density; Retinal periphery; Retinal vessel density; Widefield optical coherence tomography angiography.