Glaucoma can affect patients of all ages and is the leading cause of blindness and visual impairment in the United States. Glaucoma is a family of eye diseases that gradually steal sight without warning. Glaucoma causes damage to the optic nerve, which is responsible for relaying visual information from the retina to the brain. Over 4 million Americans have glaucoma, but only half of those affected are aware since there may be no symptoms in the early stages of the disease. Early detection and treatment are imperative in maintaining overall eye health and vision.
Glaucoma initially causes damage to the peripheral vision. Later in the disease our central vision can be affected. There are two main types of glaucoma: A. Open Angle and B. Angle Closure. Both types involve abnormalities with the drainage angle that helps aqueous flow from the eyes. If aqueous fluid is not drained properly, the pressure in the eye can increase. If eye pressure is elevated for an extended period of time, permanent drainage and progressive vision loss can occur.
A simple, painless eye exam can detect the disease. With early detection and treatment, glaucoma can usually be controlled and blindness prevented.
Open-angle glaucoma is the most common form of the disease, and is completely painless with absolutely no symptoms. In the healthy eye, a clear fluid called aqueous circulates inside the front portion of your eye. To maintain a constant healthy eye pressure, your eye continually produces a small amount of aqueous while an equal amount of this fluid flows out of your eye through the trabecular meshwork.
In open angle glaucoma, drainage abnormalities cause the internal eye pressure to increase as fluid builds up, which then deprives the optic nerve of oxygen and nutrients and leads to irreversible optic nerve damage. The damage caused by open-angle glaucoma is often so slow that patients may not notice any changes to their vision until significant damage has already occurred.
Angle-closure glaucoma, also called narrow-angle glaucoma, is much less common. Angle-closure glaucoma affects only about one out of every ten glaucoma patients, and involves a blockage in the normal flow of aqueous. This can lead to symptoms such as redness, discomfort, blurred vision, and headaches. This blockage is more common in patients who are farsighted, have dense cataracts, or have structural abnormalities in the eye.
This type of glaucoma can develop suddenly or gradually, depending on the cause. Most patients who develop angle-closure glaucoma are born with narrow drainage angles that put them at a higher risk for developing this condition.
Glaucoma is known as a silent disease. In its early stages, glaucoma has no symptoms. If the disease goes untreated and progresses, blind spots develop in your peripheral (side) vision. Symptoms of advanced glaucoma may include severe eye or brow pain, redness of the eye, decreased or blurred vision, seeing colored rainbows or halos, headache, nausea, or vomiting. Blind spots in the side vision may not be noticeable until the optic nerve has become severely damaged — or until detected by an ophthalmologist during a complete exam.
Glaucoma Risk Factors
Glaucoma can affect anyone from newborn infants to the elderly. People who are at a greater risk for glaucoma usually have the following conditions:
- Family history of glaucoma
- African or Hispanic ancestry
- Farsightedness or nearsightedness
- Elevated eye pressure
- Past eye injury
- Having a thinner central cornea (the clear, front part of the eye covering the pupil and colored iris)
- Not having eye examinations when they are recommended
- Low blood pressure
- Conditions that affect blood flow, such as migraines, diabetes and low blood pressure