|
|
What is glaucoma?
Glaucoma is the leading cause of blindness in the United States, especially for older people. But the loss of sight from glaucoma is often preventable if you get treatment early enough.
Glaucoma is a disease of the optic nerve. Many people know that glaucoma has something to do with pressure inside the eye. The higher the pressure inside the eye, the greater the chance of damage to the optic nerve. The optic nerve is made up of many nerve fibers, and glaucoma can damage them, causing blind spots to develop. Usually people don't notice these blind spots until much of the optic nerve has been destroyed. If the entire nerve is destroyed, blindness results.
What causes glaucoma?
Clear liquid, called the aqueous humor, circulates inside the eye. A small amount of this fluid is produced constantly, and an equal amount flows out of the eye through a microscopic drainage system. (This liquid is not part of the tears on the outer surface of the eye.) You can think of the flow of aqueous fluid as a sink with the faucet on all the time.
If the "drainpipe" gets clogged, water collects in the sink and the sink may overflow. Because the eye is a closed structure, the excess fluid cannot overflow if the drain is clogged. If the drainage area of the eye--called the drainage angle--is blocked, the fluid pressure within the eye may increase, which can damage the optic nerve.
What are the main types of glaucoma?
Chronic open-angle glaucoma: This is the most common form in the United States, and it occurs as a result of aging. The drainage angle of the eye becomes less efficient with time, gradually increasing pressure within the eye.
Angle-closure glaucoma: This occurs when the drainage angle of the eye becomes completely blocked.
Who is at risk for glaucoma?
High pressure alone does not mean that you have glaucoma. Your ophthalmologist considers many variables in determining your risk for developing the disease. The mose important risk factors include:
- Age;
- African ancestry;
- A family history of glaucoma;
- Past injuries to the eyes.
How is glaucoma treated?
As a rule, damage caused by glaucoma cannot be reversed. It is usually controlled with eye drops taken several times a day, sometimes in combination with pills. These medications decrease eye pressure, either by slowing the production of aqueous fluids or by improving the flow through the drainage angle.
Laser surgery treatments may be effective for different types of glaucoma. In open-angle glaucoma, the drain itself is treated. The laser is used to modify the drain (trabeculosplasty) to help control eye pressure. In angle-closure glaucoma, the laser creates a hole in the iris (iridotomy) to improve the flow of aqueous fluid to the drain.
|
|
|
