AIM:To quantitatively evaluate the macular microvasculature and visual function in patients with macular edema secondary to retinal vein occlusion(RVO)by optical coherence tomography angiography(OCTA)combined with microperimetry. METHODS: Totally 36 patients(36 eyes)with monocular RVO complicated with macular edema were enrolled, including 15 patients(15 eyes)in central retinal vein occlusion(CRVO)group and 21 patients(21 eyes)in branch retinal vein occlusion(BRVO)group(all with superior temporal vein occlusion), 15 age-matched healthy subjects(24 eyes)were included as controls. OCTA was used to scan macular retina in the range of 3mm×3mm in all three groups and measure the vascular density(VD)of superficial capillary plexus(SCP)and deep capillary plexus(DCP), the area of foveal avascular zone(FAZ)and the central retinal thicknes(CRT); the retinal mean sensitivity(RMS)at 10°was measured by MP-3 microperimetry. VD and RMS in BRVO group were further divided into lesion area(superior), non-lesion area(inferior)VD and RMS. The lesion area and non-lesion area of the control group were divided according to corresponding regions of the BRVO group. The changes of above indexes in CRVO group and BRVO group were compared with control group respectively, and the correlation between RMS and VD, CRT and FAZ areas in CRVO group and BRVO group was analyzed.RESULTS:The overall VD(SCP and DCP)in CRVO group were lower than those in control group(t= -2.536, P=0.016; t= -8.834, P