Glaucoma is a term used to describe a disease of the eye that causes damage to the optic nerve, vision loss, and can eventually lead to blindness.
Risk factors for developing glaucoma include:
- Age. Although it can develop at any age, people over the age of 60 are six times more likely to develop this disease.
- Ancestry. Glaucoma is six to eight times more common in African-Americans than in Caucasians.
- Family history of glaucoma
- Personal history of diabetes
- Personal history of heart disease
- Use of steroid medications
- Poor vision (both farsightedness and nearsightedness)
- Eye injury
There are often no symptoms. Because damage to the optic nerve, and in turn to vision, occurs gradually, by the time a patient notices a vision problem, it is unfortunately too late to reverse the damage.
When symptoms do occur, they may include:
- eye pain
- blurred vision
- rainbows or halos around lights at night
Types of Glaucoma
There are several types of glaucoma:
Open angle glaucoma is the most common type. The drainage canals become clogged over a long period of time. Eye pressure builds gradually because the fluid within the eye cannot drain.
At first there are no symptoms. Without treatment, vision diminishes gradually over many years. If diagnosed and treated early, this type of glaucoma responds well to treatment.
Closed angle glaucoma, also known as narrow angle or acute glaucoma. Symptoms can include severe eye pain, blurred vision, and seeing rainbow colored halos around lights.
In this type of glaucoma, eye pressure usually increases rapidly. The iris and cornea are not as wide and open as they normally should be. The outer edge of the iris covers the drainage canals when the pupil enlarges quickly, such as when entering a dark room.
Secondary glaucoma can be caused by use of corticosteroid medications, because of eye injury, diabetes, other eye diseases such as uveitis, and advanced cataracts.
This type of glaucoma can be mild or severe, and treatment depends on whether it is open angle or closed angle glaucoma.
There are several forms of secondary open angle glaucoma:
- Pigmentary glaucoma develops when the pigment granules in the back of the iris break into the clear fluid inside the eye. These granules slowly clog the drainage canals, causing eye pressure to rise.
- Traumatic glaucoma is caused by an eye injury, and can occur either immediately after the injury or years later.
- Pseudoexfoliative glaucoma develops when flaky, dandruff-like material peels off the outer layer of the lens of the eye. These flakes collect in the angle between the cornea and iris and clog the drainage canal, causing pressure within the eye.
- Neovascular glaucoma is caused by abnormal formation of new blood vessels on the iris and over the drainage canals. This type of glaucoma is always associated with other diseases, most commonly diabetes. Neovascular glaucoma is very difficult to treat.
- Normal tension glaucoma. In this type of glaucoma, the optic nerve becomes damaged even though the pressure in the eye is normal or not very high. Development of normal tension glaucoma is more common in people with a history of heart disease. It is detected by examining the optic nerve.
Irido Corneal Endothelial Syndrome is a rare form of glaucoma and is usually found only in one eye. Cells on the rear surface of the cornea spread over the drainage canals of the eye and across the surface of the iris, causing an increase in eye pressure. This can lead to damage of the optic nerve.
This type of glaucoma is difficult to treat, but is usually treated with medication or surgery.
Congenital glaucoma, which is hereditary and present at birth. It's caused by a defect in the fluid outflow channels in the eye.
Symptoms include light sensitivity, redness of the eye, haziness and enlargement of the cornea, and tearing. This type of glaucoma can be corrected by surgery.
Unfortunately, once glaucoma develops, although further development can be controlled, in most instances, the damage to vision cannot be reversed.
Although glaucoma cannot be cured, it can be treated and kept from progressing if diagnosed early by having regular eye examinations.
Treatment can include various types of eye drops and oral medications that can be prescribed by your physician.