Glaucoma is the leading cause of blindness in the United States, especially in the elderly population. Loss of sight can be preventable, however, if treatment is received early enough. Glaucoma is a disease of the optic nerve. The optic nerve is the cable that takes the signals from the eye to the brain. The retina is the nerve layer in the back of the eye which is like the film in a camera. It “sees” the picture and converts it to electrical signals that are carried in “wires” called axons. These axon “wires” are then arranged in the optic nerve cable going to the brain. Glaucoma is damage to these axon wires, causing blind spots to develop. This damage is usually slow and painless and people often don”t realize how much these blind areas have progressed until much damage has occurred. Early detection and treatment are the keys to preventing optic nerve damage and blindness from glaucoma.
FAQs
What causes glaucoma?
Current research in glaucoma suggests that the cause of this optic nerve damage is because of poor blood flow to the optic nerve and back of the eye. It is known that high eye pressure can cause progression of glaucoma.
What is eye pressure?
Your eye makes fluid to keep it inflated–so you have a grape instead of a raisin for an eye. This fluid is constantly being made inside your eye and constantly being drained, also inside of your eye by little drains at the sides of the iris called the trabecular meshwork. If the drains aren”t working well, or get clogged, the pressure inside of your eye can build up, which will then lead to damage to the optic nerve.
What are the different types of glaucoma?
Chronic open-angle glaucoma is the most common form in the United States. It occurs generally as a result of aging. The trabecular meshwork drain becomes less efficient with time and the eye pressure gradually increases, eventually damaging the optic nerve. Over 90% of glaucoma in the U.S. is of this type. It is painless and very gradual in progression, often with people unaware of it. Angle-closure glaucoma is caused by a sudden blockage of the trabecular meshwork drains by the iris. People who have this have irises which are very close to the drains and can block them suddenly, especially when the pupil is dilated–in the dark or even by the eye doctor! When the drains are suddenly blocked it is called an acute angle-closure, the eye pressure will climb very high and the person will notice the following: Blurred vision; Severe eye pain; Headache; Rainbow haloes around lights; Nausea and vomiting. If you have any of these symptoms, call and opthalmologist immediately. Blindness or damage to the optic nerve can occur very quickly at a very high eye pressure. This condition is more common in people of Asian descent and rare in people of African descent.
Who is at risk?
The most important risk factors are: Age. It is more common the older you get; African ancestry; A family history of glaucoma; Past injury to the eye. Your ophthalmologist will weigh all of these factors when deciding to start treatment or to just watch your eyes closely as a glaucoma suspect. This means that your risk for glaucoma is higher than normal, and that you need to be watched more carefully for optic nerve damage.
How is glaucoma treated?
As a rule, any damage already done by glaucoma cannot be reversed. Treatment is directed at stopping any further damage. Medicines. Many times eye pressure and glaucoma can be controlled with eye drops. These drops either slow the production of fluid within your eye or improve the drainage of the fluid. Laser surgery. Laser surgery can be helpful in one of two ways. In open-angle glaucoma, the laser can be used to modify the drain (trabeculoplasty) and make it work better. In angle-closure glaucoma, the laser is used to create a hole in the iris and allow fluid to reach the drains (iridoto).
What is Operative surgery?
When operative surgery is needed to control glaucoma, the ophthalmologist creates a drainage channel in the side of the eye for fluid to flow from the inside to the outside of the eye.
How often should I have my eyes checked for glaucoma?
The American Academy of Ophthalmology suggests the following schedule:
Age 20-39: Individuals of African descent or with a family history of glaucoma should have a medical eye examination every 3 to 5 years. Others can be seen at least once during this period; 40-64: Every 2 to 4 years; Age 65 or older: Every 1 to 2 years.
