Association of the pattern of retinal capillary non-perfusion and vascular leakage with retinal neovascularization in proliferative diabetic retinopathy

Purpose: To explore the correlation between retinal capillary non-perfusion and the distribution of retinal neovascularization and vascular leakage (VL) in patients with proliferative diabetic retinopathy (PDR). Methods: Ultra-widefield angiograms of 96 eyes of 69 patients with PDR were reviewed for the proportion of non-perfused area to total gradable area, and for the presence of neovascularization and VL. Results: Retinal neovascularization was distributed as such: neovascularization elsewhere (NVE), 57.3%; neovascularization of the disc (NVD), 11.5%; both neovascularization of the disc and elsewhere (NVED), 31.3%. The proportion of non-perfused retina, so-called ischemic index, was greater in eyes with NVED compared to eyes with NVE only, but not when compared to NVD only. Overall, 83% of eyes had VL. The presence and the extent of VL correlated with the proportion of the ischemic index. While VL and ischemic index were more severe in the mid-periphery and far-periphery, the majority of NVE was located in the posterior pole. Conclusions: The presence of both NVD and NVE is associated with a greater ischemic index than NVE alone. Although both VL and ischemic index is significantly higher in peripheral zones, the majority of neovascularization occurs at the posterior pole.