AIM: To observe the changes of macular microvascular parameters and their correlation with best corrected visual acuity(BCVA)in patients with branch retinal vein occlusion(BRVO)by using optical coherence tomography angiography(OCTA).

METHODS: The superficial retinal capillary layer in the posterior pole of 29 patients with BRVO was scanned by OCTA. Macular vascular density including vessel density(VD), perfusion density(PD), foveal avascular zone(FAZ), and morphological index were obtained at baseline, 1 and 6mo respectively.

RESULTS: The FAZ area in BRVO group was 0.32±0.08mm², significantly larger when compared to the fellow eyes(0.21±0.06mm²)(t=-6.958, P<0.001). The VD of full area of 3mm×3mm and 6mm×6mm was lower in BRVO eyes compared to fellow eyes(P<0.05). As for PD, a difference was found between the two groups in the central and inter area in the 3mm×3mm scan pattern(P<0.001), while a significant difference was found in central, the outer, and the full area in the 6mm×6mm scan pattern(P<0.05). The BCVA at baseline was significantly better than that at 6mo(t=2.43, P<0.05); BCVA(LogMAR)was positively correlated with VD and PD of centre area in 3mm×3mm mode, and PD of central and full area in 6mm×6mm model, but negatively correlated with PD in the outer area in 6mm×6mm mode.

CONCLUSION: As a non-invasive examination, quantitative OCTA measurements confirm vascular density changes in the superficial vascular networks in eyes with BRVO. Moreover, vascular density and FAZ area appear to correlate with visual function.