Correlation between macular perfusion status and visual acuity in retinal vein occlusion

Retinal vein occlusion (RVO) is the second most common retinal vascular disease worldwide, and the retinal perfusion status is closely related to the prognosis of the disease. Macular perfusion status is particularly correlated with visual acuity. This study aims to investigate the changes in macular perfusion indicators in RVO using optical coherence tomography angiography (OCTA) and analyze the correlation between macular perfusion status and visual acuity.

This cross-sectional study included 41 RVO patients, who were divided into 2 groups based on the occlusion site: 18 cases in the central retinal vein occlusion (CRVO) group and 23 cases in the branch retinal vein occlusion (BRVO) group. Additionally, they were categorized into ischemic RVO (23 cases) and non-ischemic RVO (16 cases) groups based on the presence of ischemia (2 eyes were excluded due to hemorrhage obscuring the peripheral retina, making it impossible to confirm the area of non-perfusion). A control group of 29 healthy individuals matched by sex and age was also recruited. Macular perfusion indicators were measured using OCTA, and the correlation between macular perfusion status and visual acuity was analyzed.

Compared with healthy eyes, RVO eyes showed an increased foveal avascular zone (FAZ) area and significantly reduced superficial and deep vessel density (P<0.001). However, there were no significant differences in central foveal thickness (CFT) or macular perfusion indicators between the CRVO and BRVO groups (P>0.05). The best corrected visual acuity (BCVA) at the logarithm of the minimum angle of resolution (logMAR BCVA) was significantly negatively correlated with both superficial and deep retinal vessel density in RVO eyes (unstandardized coefficient B=-0.039, B=-0.042; P=0.017, P=0.040). The average BCVA in the ischemic RVO group was significantly worse than that in the non-ischemic RVO group (0.82±0.44 vs 0.45±0.29, P=0.007). The ischemic RVO group also had a larger FAZ area (P=0.003) and lower superficial and deep retinal vessel density (P<0.001, P=0.008, respectively) compared with the non-ischemic RVO group. The severity of macular ischemia did not correspond directly with the peripheral ischemia severity in RVO.

Macular perfusion status is significantly reduced in RVO eyes compared to healthy eyes, which negatively impacts and limits visual acuity in RVO patients. Eyes with ischemic RVO have poorer visual acuity and macular perfusion status than those with non-ischemic RVO. OCTA is advantageous for observing vascular morphology and quantifying macular perfusion status, making it an effective tool for assessing disease progression.