GLAUCOMA

American Academy of Ophthalmology

What is glaucoma?
Glaucoma is a disease of the optic nerve, which is 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 electrical 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 your ophthalmologist (Eye M.D.) are the keys to preventing
optic nerve damage and blindness from glaucoma.
Glaucoma is the leading cause of blindness I 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 the aqueous humor, circulates inside the front portion of 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, maintaining a constant level of pressure within the eye. (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 will increase, pushing against the opt nerve and potentially causing damage.
What are the different types of glaucoma?
Chronic open-angle glaucoma: This is the most common form of glaucoma in the United
States.
The risk of developing chronic open-angle glaucoma increases with age. The drainage angle of
the eye becomes less efficient over time, and pressure within the eye gradually increases, which
can damage the optic nerve. In some patients, the optic nerve becomes sensitive to normal eye
pressure and is at risk for damage. Treatment is necessary to prevent further vision loss.
Chronic open-angle glaucoma damages vision so gradually and painlessly that you are not aware
of trouble until the optic nerve is already injured.
Closed- angle glaucoma: Sometimes the drainage angle of the eye may become completely
blocked. In the eye, the iris (the part that makes eyes blue, brown, or green) may drop over and
completely close of the drainage angle. You can imagine this occurring much like a sheet of

paper floating near a drain. If the paper suddenly drops over the opening the flow is abruptly
blocked.
When eye pressure builds up suddenly, an acute closed-angle glaucoma attack occurs.
Symptoms may include:
blurred vision;
severe eye pain;
headache;
rainbow-colored halos around lights;
nausea and vomiting.
This is a true eye emergency. If you have any of these symptoms, call your ophthalmologist
immediately. Unless this type of glaucoma is treated quickly, blindness can result.
In some patients, glaucoma has features of both the chronic open-angle type and the acute
closed-angle type. This may be called chronic closed-angle glaucoma or mixed mechanism
glaucoma.
Who is at risk for glaucoma?
Your ophthalmologist considers many kinds of information to determine your risk for developing
the disease.
The most important risk factors include:
age;
elevated eye pressure;
family history of glaucoma;
African ancestry;
nearsightedness;
past eye injuries;
diabetes
Your ophthalmologist will weigh all of these factors before deciding whether you need treatment
for glaucoma, or whether you should be monitored closely as a glaucoma suspect. This means
your risk for developing glaucoma is higher than normal, and you need to have regular
examinations to detect the early signs of damage to the optic nerve.
How is glaucoma detected?
Regular eye examinations by your ophthalmologist are 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 for 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 methods used to help prevent further damage. In some cases, oral
medications may also be prescribed.
With and 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.
Medications
Glaucoma is usually controlled with eyedrops taken on a daily basis. These medications
decrease eye pressure, either by slowing the amount of aqueous fluid produced within the eye or
by improving the flow through the drainage angle.
Never change or stop taking your medications without consulting your ophthalmologist. If you
are about to run out of your medication, ask your ophthalmologist if you should have it refilled.
Glaucoma medications can preserve your vision, but they may also produce side effects. You
should notify your ophthalmologist if you think you may be experiencing side effects.
Some eyedrops may cause:
a stinging sensation;
red eyes or redness of the skin surrounding the eyes;
changes in pulse and heartbeat;
changes in energy level;
changes in breathing (especially with asthma or emphysema);
dry mouth;
changes in sense of taste;
headaches;
blurred vision;
changes in eye color;
All medications can have side effects or can interact with other medications. Therefore, it is
important that you make a list of the medications you regularly take and share this list with each
doctor you see.

Laser surgery
Laser surgery treatment may be recommended for different types of glaucoma.
In open-angle glaucoma, the drain itself is treated. The laser is used to modify the drain
(trabeculoplasty) to help control the eye pressure. In closed-angle glaucoma, the laser creates a
hole in the iris (iridotomy) to improve the flow of aqueous to the drain.
Surgery in the operating room
When surgery in the operating room is needed to treat glaucoma, your ophthalmologist uses fine,
microsurgical instruments to create a new drainage channel for aqueous fluid to leave the eye.
Should this type of surgery be necessary, your ophthalmologist can provide you with information
about this procedure. As with laser surgery, surgery in the operating room is typically an
outpatient procedure.
There are risks with all types of surgery. Though serious complications of modern glaucoma
surgery are uncommon, they can occur. Surgery is recommended if your ophthalmologist feels
that it is necessary to prevent further damage to the optic nerve.
What is your part in treatment?
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 doctors
instruction and take your eyedrops.
Once you are taking medications for glaucoma, your ophthalmologist will want to see you more
frequently. Typically, you can expect to visit your ophthalmologist every three to four months.
This will vary depending on your treatment needs.
Loss of vision can be prevented
Regular medical eye exams may help prevent unnecessary vision loss. Recommended intervals
for eye exams are:
Age 20-39: Individuals of African descent or with a family history of glaucoma
should have a medical exam every 3 to 5 years. Others can be seen at least once
during this period;
Age 40-64: Every 2 to 4 years;
Age 65 or older: Every 1 to 2 years.
Resources
For more information, please contact:
The American Academy of Ophthalmology (www.aao.org)

The Glaucoma Foundation

116 John Street, Suite 1605
New York, NY 10038
Phone: 1-800-GLAUCOMA (1-800-452-8266)
www.glaucoma-foundation.org
Research to Prevent Blindness
645 Madison Avenue
New York, NY 10022-1010
Phone: 1-800-621-0026
www.rpbusa.org
Published by The American Academy of Ophthalmolgy 2002.