Each participant undergo the following tests:
1. Standard ophthalmic examination (usual care): Best-corrected visual acuity, biomicroscopy (look at front of eye), intraocular pressure (IOP) using Goldman applanation tonometry, central corneal thickness measurement and fundoscopy (look at back of eye).
2. Octopus Visual Field (OVF) Analyzer using G-top strategy recording mean deviation (MD) and pattern standard deviation (PSD).
3. Heidelberg Edge Perimeter (HEP) standard automated perimetry (SAP) using advanced staircase thresholding algorithm (ASTA).
4. Spectralis optical coherence tomography (OCT) using glaucoma module premium edition (GMPE) software to measure minimum rim width (MRW) and retinal nerve fiber layer (RNFL) thickness in 6 sectors (superior nasal, superior temporal, inferior nasal, inferior temporal, nasal and temporal) in the retina.
Order of HEP SAP III and OVF, and order of the eye tested (right vs. left) if both eyes of patients meet inclusion criteria will be randomized. Patients with glaucoma will be randomly chosen and asked to return in 3 to 6 months for repeat HEP and OVF testing.
