What is glaucoma?

Glaucoma is a disease of the optic nerve-the part of the eye that carries the images we see to the brain. The optic nerve is made up of many nerve fibers, like an electric cable containing numerous wires. When damage to the optic nerve fibers occurs, blind spots develop. These blind spots usually go undetected until the optic nerve is significantly damaged. If the entire nerve is destroyed, blindness results.

Early detection and treatment by our ophthalmologist are the keys to preventing optic nerve damage and blindness from glaucoma. Glaucoma is a leading cause of blindness in the United States, especially for older people. But loss of sight from glaucoma can often be prevented with early treatment.

What causes glaucoma?

Clear liquid called aqueous humor circulates inside the front portion of the eye. To maintain a healthy level of pressure within the eye, a small amount of this fluid is produced constantly while 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.)

Because the eye is a closed structure, if the drainage area for the aqueous humor-called the drainage angle-is blocked, the excess fluid cannot flow out of the eye. Fluid pressure within the eye increases, pushing against the optic nerve and causing damage.

How is glaucoma detected?

Regular eye examinations by an ophthalmologist is the best way to detect glaucoma. A glaucoma screening that checks only the pressure of the eye is not sufficient to determine if you have glaucoma. The only sure way to detect glaucoma is to have a complete eye examination.

During your glaucoma evaluation, your ophthalmologist will:

  • Measure your intraocular pressure (tonometry).
  • Inspect the drainage angle of your eye (gonioscopy).
  • Evaluate whether or not there is any optic nerve damage (ophthalmoscopy).
  • Test the peripheral vision of each eye (visual field testing, or perimetry).

Photography of the optic nerve or other computerized imaging may be recommended. Some of these tests may not be necessary for everyone. These tests may need to be repeated on a regular basis to monitor any changes in your condition.

How is glaucoma treated?

As a rule, damage caused by glaucoma cannot be reversed. Eyedrops, laser surgery, and surgery in the operating room are used to help prevent further damage. In some cases, oral medications may also be prescribed.

With any type of glaucoma, periodic examinations are very important to prevent vision loss. Because glaucoma can progress without your knowledge, adjustments to your treatment may be necessary from time to time.

Treatment for glaucoma requires teamwork between you and your doctor. Your ophthalmologist can prescribe treatment for glaucoma, but only you can make sure that you follow your doctor’s instructions and use your eyedrops.