What is Glaucoma?
Glaucoma is an eye disease that causes a characteristic pattern of damage to the optic nerve that can lead to progressive vision loss and blindness. Glaucoma is often called the “sneak thief of sight” because it is generally painless and the associated vision loss is gradual and usually goes unnoticed until late stages of the disease. Approximately 3 million Americans have glaucoma, and it is the leading cause of irreversible blindness in African-Americans.
How is Glaucoma Detected?
- Slit lamp exam with tonometry (to look closely at the front part of the eye and measuring intraocular pressure)
- Pachymetry (to measure the corneal thickness which helps determine glaucoma risk)
- Gonioscopy (to look at the eye’s drainage angle to detect risk of angle closure and other causes of elevated intraocular pressure)
- Visual Field testing (to check the peripheral vision)
- Dilated eye exam (to evaluate the optic nerve for signs of damage and to look for retinal diseases)
- Photography or other optic nerve imaging (to document the baseline appearance of the nerve and/or to detect thinning of the retinal nerve fiber layer)
Glaucoma is frequently associated with increased pressure within the eye. There is a reduced drainage of fluid (aqueous humor) that is continuously produced within the eye that is caused by a damaged outflow system (the trabecular meshwork). The aqueous builds up inside the eye causing increased eye pressure that can contribute to optic nerve damage.
It is important to note that the exact cause of the most common type of glaucoma is still uncertain. Glaucoma can develop even in the people with normal eye pressures. Risk factors for glaucoma include increased eye pressure, family history of glaucoma, African-American heritage, and increasing age. Other factors such as low blood pressure and poor blood flow may contribute to optic nerve damage even at normal intraocular pressure levels.
The goal of treatment is to decrease eye pressure to prevent further optic nerve damage and vision loss. Treatment cannot, however, reverse damage that has already occurred. Glaucoma can be treated with eye drops, laser, or ocular surgery depending on the patient’s needs and the stage of the disease. It is very important to identify glaucoma early and keep it under control.
Did You Know?
- Half of all people with glaucoma don’t know they have it.
- 20-30% of people with glaucoma do not have elevated intraocular pressure.
- Most people do not develop symptoms until they reach advanced stages of glaucoma.
- Approximately 2% of individuals over age 40 in the United States have glaucoma.
- Glaucoma can also occur in younger persons, especially if they have a family history of glaucoma. Glaucoma also tends to occur at a younger age in African-Americans.
- Blindness is 6-8 times more common in African-Americans than Caucasians.
- Most drug companies have patient assistance programs that will provide discounted or free eye drops to those without insurance who cannot afford their medications.