Distribution of Nonperfusion and Neovascularization on Ultrawide-Field Fluorescein Angiography in Proliferative Diabetic Retinopathy (RECOVERY Study): Report 1

Purpose: To explore the distribution of nonperfusion area (NPA) on ultrawide-field fluorescein angiography (UWF FA) in proliferative diabetic retinopathy (PDR) and its relationship with the presence of neovascularization of the optic disc (NVD) and distribution of neovascularization elsewhere (NVE). Design: Prospective, observational case series. Methods: Baseline Optos 200Tx UWF FA images of 38 eyes with treatment-naïve early-stage PDR from the RECOVERY (NCT02863354) study were stereographically projected at the Doheny Image Reading Center. Two independent/masked certified graders manually delineated the NPA and the total visible retinal area (TRA). NPA and TRA were then computed in square millimeters using the manufacturer software. Ischemic index (ISI) was calculated by dividing NPA by TRA. NPA and ISI were correlated with the presence and distribution of neovascularization in the corresponding zones. Results: Eyes with NVD appeared to have more severe global NPA than those without (P =.026). Although the ISI appeared to increase with increasing distance from the foveal center (P <.001), NVE was more likely to be located in the posterior pole than the midperiphery or far-periphery (P <.001). Presence of NVE in the posterior polar retina appeared to demonstrate more severe ischemia in the posterior pole and midperiphery than those without (P <.05), but interestingly, was not correlated with the severity of overall global ischemia or of ischemia in the far-periphery alone (P >.05). Conclusions: Whereas the presence of NVD was associated with the severity of global ischemia, the distribution of NVE did not appear to be influenced by the distribution of ischemia.