Optical coherence tomography angiography microvascular findings in macular edema due to central and branch retinal vein occlusions

The aim of this study was to evaluate retinal and choriocapillaris vessel density using optical coherence tomography angiography (OCTA) in eyes with central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO) complicated by macular edema (ME). Sixty eyes of 60 patients with CRVO or BRVO and ME and 40 healthy subjects underwent measurements of superficial and deep foveal and parafoveal vessel density (FVD, PFVD) and choricapillary density using OCTA at baseline and 60 days after intravitreal dexamethasone implant (IVDEX). FVD and PFVD of the superficial plexus were not significantly lower in CRVO group compared to the controls while in the BRVO group overall PFVD were significantly lower compared to control group (p<0.001). Overall PFVD of the deep plexus was significantly lower in CRVO and BRVO groups compared to the control group (p<0.001). FVD and overall PFVD of choriocapillaris were significantly reduced compared to controls in CRVO group (p<0.001) and PFVD of choriocapillaris was significantly reduced compared to controls in the affected hemi fields in BRVO groups (p<0.001). OCTA showed vessel density reduction in BRVO and CRVO with main involvement of the deep retinal plexus compared to the superficial retinal plexus due to ischemia that did not recover after intravitreal dexamethasone implant.