Quantitative Optical Coherence Tomography Angiography Features and Visual Function in Eyes With Branch Retinal Vein Occlusion

Abstract

To measure the vascular density and foveal avascular zone (FAZ) area in the deep and superficial retinal vascular networks using optical coherence tomography angiography (OCTA) in patients with branch retinal vein occlusion (BRVO). Retrospective observational case series. Patients with unilateral BRVO involving the macula were enrolled. OCTA was performed on the BRVO and fellow eyes. Macular vascular density, FAZ area, and foveal thickness were measured in all eyes. Seventeen eyes of 17 patients met inclusion criteria. The mean overall vascular density measured in the entire scan was lower in BRVO eyes compared to fellow eyes in both the superficial (48.07% vs 52.60%, respectively; P < .001) and deep (52.60% vs 57.67%, respectively; P < .001) networks. In both networks, the density was lower in the affected BRVO sector compared to the unaffected sector in the same eye and in the fellow eye (P < .001). In the deep network, the density was lower in the unaffected sector of the BRVO eye compared with the corresponding sector in the fellow eye (58.87% vs 61.65%, respectively; P= .04). A negative correlation was found between the logarithm of the minimal angle of resolution (logMAR) visual acuity and the overall density in superficial (r=-0.40, P= .02) and deep (r=-0.38, P= .03) networks. The mean FAZ area in BRVO eyes was significantly lower only at the level of the deep network when compared to the fellow eyes (0.519mm(2) vs 0.410mm(2), respectively; P= .02) and correlated positively with logMAR (r= 0.34, P= .04). In eyes with BRVO, quantitative OCTA measurements confirm decreased vascular density in both the superficial and deep vascular networks. Moreover, vascular density and FAZ area appear to correlate with visual function.