Background: Glaucoma is a known cause of irreversible blindness worldwide. Several techniques are used for its diagnosis and follow-up. Optical coherence tomography angiography (OCTA) is new technology that provides a quantitative assessment of the microcirculation of the retina and optic nerve in a rapid, noninvasive method. Objective: To evaluate the changes at the macular vessel density (MVD) in primary open glaucoma patients (POAG) to correlate these changes with the changes of both ganglion cell complex (GCC) thickness and retinal nerve fiber layer (RNFL) thickness. Patients and Methods: Fifty healthy participants and fifty primary open angle glaucoma (POAG) subjects underwent visual field analysis, measurement of the whole image MVD, measurement of the average (RNFL) thickness, and measurement of the average thickness of (GCC). The area under the curve (AUC) was assessed for each parameter to differentiate POAG from healthy eyes. Results: MVD was lower in POAG than in the control group. The glaucomatous group showed that MVD was 21.18 ± 2.6 at the fovea, while it was 39.5 ± 4.71 at the parafovea. There was a statistically significant positive correlation between MVD (foveal and parafoveal (especially at the superior quadrant) and the mean deviation (MD) (R+ve, P < 0.05). There was a statistically significant positive correlation between MVD and structural parameters. The ROC curves showed that the cut-off points were < 28.2 and < 48 for MVD at the fovea and parafoveal area respectively, at the superficial vascular plexus with 100% sensitivity & 100% specificity between the controls and POAG eyes. Conclusions: MVD was reduced in cases with POAG compared to the control group. The assessment of macular vessel density by OCTA gave us good diagnostic abilities for diagnosis and management of glaucoma.