Open angle glaucoma (OAG) is considered a common cause of irreversible vision loss worldwide. It is an optic neuropathy associated with progressive loss and degeneration of the retinal ganglion cell layer (RGC) and its axons (retinal nerve fiber layer; RNFL), which lead to neuroretinal rim excavation and corresponding visual field defects.

Open angle glaucoma (OAG) is considered a common cause of irreversible vision loss worldwide. It is an optic neuropathy associated with progressive loss and degeneration of the retinal ganglion cell layer (RGC) and its axons (retinal nerve fiber layer; RNFL), which lead to neuroretinal rim excavation and corresponding visual field defects.

OCT Angiography (OCTA) is a promising tool for diagnosing and monitoring glaucomatous patients. It can evaluate glaucomatous damage and assess the ganglion cells' health by measuring blood flow within the optic nerve and the retina Correlation between vascular , structural and functional changes of the peripapillary retinal nerve fiber (RNFL) and macular/ganglion cell complex (GCC) can lead to early detection of glaucomatous changes.

Inclusion Criteria:

• Age of 30 years or older for both control and glaucoma groups.
• Spherical equivalent (SE) between -2 and +2 D.
• No history of previous eye surgery, trauma, or systemic diseases.

Exclusion Criteria:

• Spherical equivalent greater than +/- 2.00 diopters (D).
• Media opacity as (cataract or corneal scar).
• Any history of ocular surgeries or trauma.
• Optic nerve anomaly or other retinal diseases.
• Unreliable visual field tests (33% fixation losses, false positive, and false- negative results).

One hundreds fifty-two eyes of 76 participants were included in this study, with the participants recruited from the outpatient glaucoma clinic of Benha University Hospital, EGYPT.