Glaucoma is an eye disease characterized by increased pressure within the eye. In chronic glaucoma, the channel through which fluid (aqueous humor) drains out of the eye is obstructed, resulting in a gradual build-up of pressure inside the eye. The increasing pressure eventually collapses the small blood vessels that supply the retina and optic nerve, depriving them of nutrients and oxygen. As retinal cells and nerve fibers die, the field of vision progressively gets smaller, leading to "tunnel vision" and complete blindness. Loss of vision can be prevented only if glaucoma is detected in its early stages. Therefore, regular eye examinations are recommended, particularly for individuals over age 40.
Early stages:
- Loss of peripheral vision in small areas.
- Blurred vision on one side toward the nose.
Advanced stages:
- Larger areas of vision loss, usually in both eyes.
- Hard eyeball.
- Halos around lights.
- Blind spots.
- Poor night vision.
Physical exam of the retina may show characteristic changes in the optic nerve only late in the disease.
Tests: Measuring the pressure inside the eye establishes the diagnosis. A test of the visual fields is indicated once the diagnosis is made.
In chronic glaucoma, medication is used to decrease pressure within the eye, by either enhancing outflow of fluid or inhibiting the formation of fluid. In the occasional case where medical treatment is not effective, surgery can be done to improve drainage of fluid out of the eye (trabeculectomy or trabeculoplasty).
There is a strong association between glaucoma and diabetes, so one condition should raise the suspicion of the other. If a beta-blocker is used as treatment, depression can be induced.
With early diagnosis and treatment, useful vision is preserved for life in most cases. Untreated chronic glaucoma that begins at middle age may cause complete blindness by age 65.
Other possibilities are narrow-angle glaucoma, and secondary glaucoma (from trauma, inflammation, or following any surgery inside the eye).
- You or a family member has symptoms of chronic glaucoma.
- Medicine in the eye becomes intolerable.
- Any sign of eye infection, such as fever, develops.
- Pain begins in the eye.
- Redness occurs in the eye.
- Vision changes suddenly.