What Causes Glaucoma?
Glaucoma is a group of diseases of the optic nerve (the nerve that connects the eye to the brain). In glaucoma, the optic nerve becomes progressively damaged, leading to a loss of sight. Untreated glaucoma can lead to blindness.
Glaucoma is usually associated with an elevated pressure of the eye, but there are many people who show evidence of glaucoma damage with “normal” pressures. Likewise, many people have what are considered high intraocular pressures with no signs of glaucoma.
Risk factors for glaucoma include family history, race (with African-Americans being 3 times as likely as other races of developing glaucoma), age, higher intraocular pressures, and thin central corneal thickness.
The two most common types of glaucoma are open angle glaucoma and narrow or closed angle glaucoma, with open angle glaucoma making up more than 90% for the cases of glaucoma in the U.S. Narrow angle glaucoma is much more common in those of Asian descent. It is important to differentiate whether one has open or narrow angle glaucoma, as the treatments for each are very different.
Is Glaucoma Common?
Glaucoma is a major cause of blindness. Almost 900,000 people in the United States are visually impaired due to glaucoma. At least 2 million Americans have glaucoma or related conditions and possibly one-half of these people are not aware of it. It is the most frequent cause of blindness in African Americans and affects all races. People who have family members with glaucoma are especially at risk for developing glaucoma themselves. Glaucoma causes progressive loss of the peripheral (side) vision and may affect the central vision late in the course of the disease. Visual loss occurs so slowly that affected individuals are not aware that they are losing their vision.
How Do I Know if I Have Glaucoma?
The only way that glaucoma can be detected is by regular visits to an eye doctor. You should have your eye pressure checked and your optic nerve examined in order to detect early changes that may be seen in glaucoma. If an increased risk of glaucomais suspected, other tests may be ordered to determine the severity of the damage or to determine the risk of developing damage. These tests may include a visual field test, photos of the optic nerves, special imaging of the optic nerves, a test to examine the drainage system of the eye (gonioscopy), and a test to measure the central corneal thickness (pachymetry). As further research is done and as technology advances, newer diagnostic testing may also become available.
How Can Glaucoma be Prevented?
The most effective method for preventing loss of vision due to glaucoma is early detection. Be sure to have an annual evaluation. People who have family members with glaucoma are especially at risk for developing glaucoma themselves.
How is Glaucoma Treated?
The treatment of glaucoma is to lower the pressure of the eye. Many studies have confirmed that the lowering of the pressure of the eye reduces the risk of glaucoma damage.
Open angle glaucoma is usually treated with eye drops which lower the pressure of the eye. Laser surgery (trabeculoplasty), performed in our office, may also be used to improve the drainage of the fluid out of the eye, thereby lowering the pressure. In severe cases, surgery may be necessary to lower the pressure of the eye.
Closed angle glaucoma is treated with laser surgery to try to open the angle. In some people, the laser may prove ineffective and surgery may be required. Medications may also be necessary.
Once diagnosed with glaucoma, treatment will usually be continued for life. In some cases, especially in closed angle glaucoma, surgery may be curative. Open angle glaucoma is usually not “cured,” but can be treated in order to slow and hopefully prevent noticeable loss of vision.