Classification of the Glaucomas

Abstract

Patients with open-angle glaucoma manifest a chronic, idiopathic disease associated with progressive degeneration of the anterior optic nerve, known as glaucomatous optic neuropathy. Although elevated intraocular pressure is an important causative risk factor, only about half of the three million North Americans with glaucoma will manifest elevated intraocular pressure at a single measurement. Therefore, measurement of intraocular pressure alone is a poor screening technique for glaucoma. Like most biologic parameters, eye pressure fluctuates diurnally and with other endogenous and exogenous influences, including hydration, sleep, blood pressure, and body position. With multiple measurements at different testing sessions, many, but not all of these glaucoma subjects, will eventually exhibit elevated intraocular pressure at least part of the time.