Glaucoma is a disease of the major nerve of vision, called the optic nerve. The optic nerve receives light-generated nerve impulses from the retina and transmits these to the brain, where we recognize those electrical signals as vision.
Glaucoma is characterized by a particular pattern of progressive damage to the optic nerve that generally begins with a subtle loss of side vision (peripheral vision). If it is not diagnosed and treated, it can progress to loss of central vision and blindness.
Glaucoma is usually, but not always, associated with elevated pressure in the eye (intraocular pressure). Generally, it is this elevated eye pressure that leads to damage of the eye (optic) nerve. In some cases, glaucoma may occur in the presence of normal eye pressure. This form is believed to be caused by poor regulation of blood flow to the optic nerve.
- Glaucoma is a disease that is often associated with elevated intraocular pressure, in which damage to the eye (optic) nerve can lead to loss of vision and even blindness.
- Glaucoma is the leading cause of irreversible blindness in the world.
- Glaucoma usually causes no symptoms early in its course, at which time it can only be diagnosed by regular eye examinations (screenings with the frequency of examination based on age and the presence of other risk factors).
- Intraocular pressure increases when either too much fluid is produced in the eye or the drainage or outflow channels (trabecular meshwork) of the eye become blocked.
- While anyone can get glaucoma, some people are at greater risk.
- The two main types of glaucoma are open-angle glaucoma, which has several variants and is a long duration (chronic) condition, and angle-closure glaucoma, which may be a sudden (acute) condition or a chronic disease.
- Damage to the optic nerve and impairment of vision from glaucoma are irreversible.
- Several painless tests that determine the intraocular pressure, the status of the optic nerve and drainage angle, and visual fields are used to diagnose glaucoma.
- Glaucoma is usually treated with eyedrops, although lasers and surgery can also be used. Most cases can be controlled well with these treatments, thereby preventing further loss of vision.
- Much research into the causes and treatment of glaucoma is being carried out throughout the world.
- Early diagnosis and treatment is the key to preserving sight in people with glaucoma.