Glaucoma

Progressive optic nerve damage, the silent thief of sight

Overview

Glaucoma is a group of eye diseases characterized by progressive damage to the optic nerve, with loss of retinal ganglion cells and their nerve fibers and a characteristic pattern of visual field loss. Raised intraocular pressure is the main known risk factor, although damage can also occur at normal pressures. The most common form, primary open angle glaucoma, is typically painless and causes no symptoms until it is advanced, which is why it is called the silent thief of sight and why a large share of cases remain undiagnosed. Peripheral vision is lost first, and late disease can leave only a small central island. Risk factors include older age, family history, African ancestry, high myopia, and corticosteroid use. Diagnosis combines tonometry, examination of the optic nerve head, visual field testing, and OCT imaging of the nerve fiber layer, and treatment aims to lower pressure using eye drops, laser trabeculoplasty, or surgery. Acute angle closure glaucoma is a distinct form in which drainage is suddenly blocked, causing a painful red eye, halos, and nausea, and it is treated as an emergency. Glaucoma is a leading cause of irreversible blindness worldwide.