WHAT IS GLAUCOMA?
Glaucoma is a group of diseases that damage the eye’s optic nerve and can result in vision loss and blindness. However, with early detection and treatment, you can often protect your eyes against serious vision loss.
The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
HOW DOES THE OPTIC NERVE GET DAMAGED BY OPEN-ANGLE GLAUCOMA?
Several large studies have shown that eye pressure is a major risk factor for optic nerve damage. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of the chamber and nourishes nearby tissues. The fluid leaves the chamber at the open angle where the cornea and iris meet. When the fluid reaches the angle, it flows through a spongy meshwork, like a drain, and leaves the eye.
In open-angle glaucoma, even though the drainage angle is “open”, the fluid passes too slowly through the meshwork drain. Since the fluid builds up, the pressure inside the eye rises to a level that may damage the optic nerve. When the optic nerve is damaged from increased pressure, open-angle glaucoma-and vision loss—may result. That’s why controlling pressure inside the eye is important.
However, not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher levels of eye pressure better than others and a certain level of eye pressure may be high for one person but normal for another. In fact, glaucoma can even develop without increased eye pressure. This form of glaucoma is referred to as “low-tension” or “normal-tension” glaucoma.
WHO IS AT RISK FOR OPEN-ANGLE GLAUCOMA?
Although anyone can develop glaucoma, certain groups of people are at higher risk than others:
- African Americans over age 40
- Adult over age 60, especially Mexican Americans
- People with a family history of glaucoma
A comprehensive dilated eye exam at our office in either Tacoma or Gig Harbor can reveal more risk factors, such as high eye pressure, thinness of the cornea, and abnormal optic nerve anatomy. In some people with certain combinations of these high-risk factors, medicines in the form of eyedrops reduce the risk of developing glaucoma by about half.
At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. Glaucoma can develop in one or both eyes. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.
There is no cure for glaucoma, so any vision that is lost due to the disease cannot be restored. However immediate treatment for early-stage, open-angle glaucoma can delay progression of the disease. That’s why early diagnosis is very important.
Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma.
Medicines: Medicines, in the form of eyedrops, are the most common early treatment for glaucoma. Taken regularly, these eyedrops lower eye pressure. Some medicines cause the eye to make less fluid while others lower pressure by helping fluid drain from the eye.
Glaucoma medicines need to be taken regularly as directed by your ophthalmologist. While most people have no problems taking the eyedrops some will experience headaches or other side effects such as stinging, burning, and redness in the eyes. Fortunately, there are may medicines available to treat glaucoma, so if one medicine causes side effects, chances are good that your ophthalmologist will be able to change your dosage or switch you to a different medication.
Many medicines are available for glaucoma treatment. If you have problems with one medicine, tell our Tacoma eye care professional. Treatment with a different dose or a new medicine may be possible.
Because glaucoma often has no symptoms, people may be tempted to stop taking, or may forget to take, their medicine. You need to use the drops or pills as long as they help control your eye pressure. Regular use is very important.
Laser trabeculoplasty: Laser trabeculoplasty helps fluid drain out of the eye. Your doctor may suggest this procedure at any time. In many cases, you will need to keep taking glaucoma medicines even after this procedure is performed. For more information about laser trabeculoplasty, click here.
Conventional surgery (trabeculectomy): During this procedure, the ophthalmologist creates a new opening for the fluid to leave the eye. Conventional surgery often is done after medications and laser surgery have failed to control eye pressure. To learn more about trabeculectomy, click here.