To investigate the correlation between macular microvascular alterations on optical coherence tomography angiography (OCTA) and retinal ischemia on ultra-widefield fluorescein angiography (UWF FA) in eyes with branch retinal vein occlusion (BRVO).

Cross-sectional study.

This prospective study was performed from September 2019 to June 2020 at Yeungnam University Medical Center. We included 60 patients with treatment-naïve BRVO. Two independent, masked graders analyzed OCTA parameters, including vessel density, skeletal density, and fractal dimension (FD), and UWF FA parameters, including retinal nonperfusion area (NPA) and ischemic index (ISI), from various concentric regions (perimacular region, 0.5-3 mm radius; near-peripheral region, 3-10 mm; midperipheral region, 10-15 mm; far-peripheral region, >15 mm). A repeated-measures analysis of variance test and a paired t test were performed for inter-visit and inter-regional comparisons, and Pearson correlation coefficient and multivariate regression analyses were performed to examine the correlation between UWF FA and OCTA parameters.

The OCTA parameters from both the superficial and deep capillary plexuses (DCP) were significantly correlated with NPA and ISI in all concentric regions. Even after adjusting for several covariates, all OCTA parameters revealed a significant association with ISI on UWF FA. Moreover, OCTA parameters from DCP were significantly correlated with concentrations of placental growth factor and vascular endothelial growth factor. Although all OCTA parameters achieved excellent results of area under the curve (AUC) > 0.9 for detecting severe retinal ischemia, defined as ISI >10%, FD reduction in DCP was the most reliable parameter (AUC = 0.948, P < .001), and 5.39% was the best cut-off point for predicting ISI > 10%.

OCTA is a useful noninvasive tool not only for evaluation of macular microvasculature but for supposition of peripheral nonperfusion in eyes with BRVO.