Background: glaucoma is a major disease that potentially results in irreversible blindness, some prospective studies demonstrated that in primary open-angle glaucoma (POAG), blood flow is diminished in the ophthalmic, retinal, choroid and retro-bulbar circulations. Aim of the Work: this study aimed to compare Optic disc perfusion in normal healthy persons with that of Open Angle Glaucoma (OAG) patients by using Optical Coherence Tomography Angiography (OCTA) and to see if a correlation exists between optic disc perfusion, visual field changes and retinal nerve fiber layer thickness in normal healthy persons and in OAG patients. Patients and Methods: we did an analysis of optic disc perfusion in two groups of normal healthy persons and primary open angle glaucoma patients who were previously diagnosed and attended follow up in outpatient clinic in Sayed Galal University Hospital located in Cairo. In our study we included 22 eyes of 12 people, (10 normal eyes and 12 Open angle glaucoma patients eyes) aged between 20 and 78 years old. Results: there was a statistically significant relationship between optic disc perfusion and glaucoma group in comparison with normal group, thus in normal group the optic disc perfusion indicated good optic disc perfusion which was significantly lower in glaucoma group. Also we discovered that there was a statistically significant correlation between optic disc perfusion with (Visual field changes and RNFL thickness). Conclusion: optic disc perfusion assessment by using OCT angiography could be beneficial in evaluation of glaucoma and assessment of disease progression and it's follow up together with Visual Field assessment and clinical examination.