What is Glaucoma?
Glaucoma is a leading cause of blindness in the United States, especially for older people. However, loss of sight from glaucoma is preventable if you get treatment early enough.
Glaucoma is a disease of the optic nerve. The optic nerve carries the images we see to the brain. It acts like an electric cable containing a huge number of wires. Glaucoma can damage nerve fibers, causing blind spots to develop. Often people don’t notice these blind areas until much optic damage has already occurred. If the entire nerve is destroyed, blindness results. Early detection and treatment by your ophthalmologist are the keys to preventing optic nerve damage and blindness.
What Causes Glaucoma?
Clear liquid, called the aqueous humor, flows in and out of the eye. This liquid is not part of the tears on the outer surface of the eye. You can think of the flow of the aqueous fluid as a sink with the faucet turned on all the time.
If the drainpipe gets clogged, water collects in the sink and pressure builds up. If the drainage area of the eye—called the drainage angle—is blocked, the fluid pressure within the inner eye may increase, which can damage the optic nerve.
What are the different types of glaucoma?
Chronic Open-angle glaucoma: This is the most common glaucoma. It occurs as a result of aging. The “drainpipe” or drainage angle of the eye becomes less efficient with time.
Angle-closure glaucoma: Sometimes the drainage angle of the eye may become completely blocked. It is as though a sheet of paper floating near the drain suddenly drops over the opening and blocks the flow out of the sink.
The symptoms include:
- Blurred vision
- Severe eye pain
- Rainbow halos around lights
- Nausea and vomiting
If you have any of these symptoms call your ophthalmologist immediately.
Who is at risk?
High pressure alone does not mean that you have glaucoma. The most important risk factors include:
- African ancestry
- A family history of glaucoma
- Past injuries to the eye
How is glaucoma treated?
As a rule, damage caused by glaucoma cannot be reversed. Eye drops, pills and laser and surgical operations are used to prevent or slow down further damage from occurring. With any type of glaucoma, periodic examinations are very important to prevent vision loss. Because glaucoma can worsen without your being aware of it, your treatment may need to be changed over time.
Glaucoma 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 fluid within the eye or by improving the flow leaving the drainage angle. For these medications to work, you must take them regularly and continuously.
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 enlarge the drain. (trabeculoplasty) 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.
When operative surgery is needed to control glaucoma, your ophthalmologist uses miniature instruments to create a new drainage channel for the aqueous fluid to leave the eye. The new channel helps to lower the pressure. Although serious complications of modern glaucoma surgery are rare, they can occur, as with any surgery.
This information is provided by The American Academy of Ophthalmology.