to predict of glaucoma progression. By imaging of the retinal nerve fiber layer RNFL, optic nerve head (ONH) and macular measurements using spectral-domain OCT (SD-OCT) instruments

,and detection of optic disc perfusion changes using OCTA.

Subjects will go a comprehensive ophthalmologic examination including review of medical history, best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, intraocular pressure (IOP) measurement, gonioscopy, dilated fundoscopic examination, stereoscopic optic disc photography, and automated perimetry using Swedish Interactive Threshold Algorithm (SITA Standard 24-2). Only subjects with open angles on gonioscopy were included.

One eye of each subject will be scanned by a high-speed 1050-nm-wavelength swept-source OCT instrument.

OCT is providing measurements of the RNFL thickness, ONH, as well as the inner macula for the assessment of glaucoma progression.

The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm will be used to compute 3-dimensional optic disc angiography. A disc flow index was computed from 4 registered scans.

Evaluation of progressive changes of the optic disc and RNFL will be based on event-analysis and/or trend-analysis. In event analysis, progression is defined when the difference between the baseline and follow-up measurements of the parameter of interest is greater than its test-retest variability (or the reproducibility coefficient). In trend analysis, regression analysis is performed between the parameter of interest and time.

1. Inclusion criteria:

   • Patients older than 18 years of age with primary open-angle glaucoma (OAG) .
   • Primary OAG (POAG) diagnosed on the basis of IOP measurements more than 21 mmHg, open angle on gonioscopy (Grade 3 or 4 on Schaffer grading system for angle width), glaucomatous visual field defects consistent with glaucomatous optic disc changes.
   • Eyes with baseline macular and ONH OCT images and ONH photographs of adequate quality and r performed within 6 months of each other were selected

2. Exclusion criteria:

   • Participants with significant retinal disease.
   • non-glaucomatous optic neuropathy.
   • anomalous discs
   • any retinal pathology. A history of cataract or glaucoma surgery will not be exclusion criteria.

Subjects will go a comprehensive ophthalmologic examination including review of medical history, best-corrected visual acuity (BCVA), slit-lamp biomicroscopy, intraocular pressure (IOP) measurement, gonioscopy, dilated fundoscopic examination, stereoscopic optic disc photography