Background: Retinal vein occlusion (RVO) is the second most common retinal vascular disease after diabetic retinopathy and an important cause of visual morbidity and blindness Aim of the work: was to detect if there are diagnostic signs in the two intra retinal layers superficial network layer and deep network layer by Optical coherence tomography angiography (OCT-A) to diagnose branch retinal vein occlusion. Patients and Methods: an observational cross-sectional study included a total of ten patients with branch retinal branch retinal vein occlusion of recent onset within three months attending at the Ophthalmology Department AlAzhar University Hospitals, Cairo. Demographic data such as age, gender, sex and hypertensive history were obtained. A detailed evaluation of cases including complete anterior segment evaluation and posterior segment evaluation was done. OCT-A and fluorescein angiography (FA) were used to study the vascular morphological changes in the branch retinal vein occlusion (BRVO)area. Results: As regarding 5 disc area of retinal ischemia FA detected ischemia in 2 cases (20%), detected no ischemia in one case (10%) and was not able to evaluate ischemia in 7 cases (70%) compared to OCT-A, that detected the ischemia in the superficial retinal plexus (SCP) in 4 cases (40%) and detected no ischemia in 6 cases (60%), but it detected the ischemia in the deep retinal plexus (DCP) in 6 cases(60%) and detected no ischemia in 4 cases (40%). Conclusion: It could be concluded that that OCT-A was superior to FA in detection of macular ischemia, macular ischemia detected by OCT-A had stronger negative relation with V.A. than macular ischemia detected by FA and retinal ischemia in the DCP was more evident than that of SCP by OCT-A.