Ischemic Index and Distribution of Retinal Capillary Non-perfusion in Neovascular Glaucoma: a Retrospective Study

Abstract Purpose: To evaluate the pattern of retinal ischemia in newly diagnosed neovascular glaucoma (NVG). Methods: This is a retrospective single-center cross-sectional study of patients seen at LAC+USC Medical Center from January 2015 to April 2020. Patients with newly diagnosed NVG and ultra-widefield fluorescein angiography (UWFA) without prior panretinal photocoagulation were included. A total of 11 eyes from 10 patients met inclusion criteria. Three zones centered on the fovea were defined: posterior pole (within 2 disc-fovea lengths), mid periphery (between 2 and 3 disc-fovea lengths), and far periphery (>3 disc-fovea lengths). Ischemic index was calculated in these zones using ImageJ software. Results: The etiology of NVG was from proliferative diabetic retinopathy (n=9) and central retinal vein occlusion (n=2). Patients were aged between 48-74 years old. Ischemic index was found to be 91% in the far periphery, 77% in the mid periphery, and 42% at the posterior pole. The total average ischemic index was 76%. There was a statistically significant difference between the far periphery and posterior pole and mid periphery and posterior pole. Conclusions: High levels of retinal ischemia were found with newly diagnosed NVG. The pattern of ischemia was more pronounced in the far periphery than posterior pole.