Glaucoma This manifests as a gradual loss of the visual field, starting with a loss of peripheral vision, but eventually the entire vision will be lost if not treated. This is the most common type of glaucoma, accounting for 90% of cases in the United States, but fewer in Asian countries. Onset is slow and painless, and loss of vision is gradual and irreversible. Narrow-angle glaucoma (also "closed-angle glaucoma") the iris bows forward, narrowing the angle that drains the eye, increasing pressure within the eye. If untreated, it can lead to the medical emergency of angle-closure glaucoma. In angle-closure glaucoma (also
Normal tension glaucoma nerve head, in the absence of elevated IOP. While the excavation of the optic nerve head and the thinning of its rim appear in all kinds of glaucoma (with high tension and with normal tension,in Primary open angle glaucoma (POAG) and in secondary glaucoma), small hemorrhages close to the optic disc have been identified as a characteristic clinical sign of normal tension glaucoma. Visual field is very important to detect NTG. It shows a defect that typically appear deeper, steeper and closer to fixation comparing to patients with POAG. Since NTG is closely linked to vascular irregularities, a medical check-up