Correlations between Macular Microvascular Alterations and Peripheral Ischemia in Patients with Branch Retinal Vein Occlusion

ABSTRACT

Purpose@#We used optical coherence tomography angiography (OCTA) to investigate the correlation between retinal microvascular alteration and peripheral retinal ischemia (evaluated with the aid of ultra-widefield fluorescein angiography [UWFA]) in patients with branch retinal vein occlusion (BRVO). @*Methods@#We retrospectively analyzed 23 eyes of 23 patients with BRVO. Vessel density (VD) and the foveal avascular zone area were measured using OCTA; UWFA was employed to measure the peripheral ischemic area and the ischemic indices (ISIs) of the entire retina and concentric retinal zones. We derived correlations between these factors. Receiver operating characteristic curves were used to predict ISI employing OCTA parameters. @*Results@#The VDs of the superficial capillary plexus (SCP) correlated with the ischemic areas of all retinal zones, and the ISIs of all zones except the far-peripheral area (FPA). The VD of the deep capillary plexus (DCP) correlated significantly with the ischemic areas and ISIs of all retinal zones except those of the FPA. On multivariate linear regression analysis, the VD was significantly correlated with the ISI; when the VDs of the SCP and DCP decreased to 24.7 and 26.1% respectively, this raised a suspicion of severe ischemic conditions with ISI > 10%. @*Conclusions@#A decrease in the BRVO VD was associated with the severity of peripheral ischemia. Our findings may aid identification of high-risk patients who require invasive fluorescein angiography.