Open-angle glaucoma gets its name because the angle that allows fluid to drain
out of the anterior chamber is open. However, for unknown
reasons, the fluid passes too slowly through the meshwork drain.
As the fluid builds up, the pressure inside the eye rises. Unless
the pressure at the front of the eye is controlled, it can damage
the optic nerve and cause vision loss.
Although anyone can get glaucoma, some people are at higher risk than others. They include: People with a family history of glaucoma.
What are the symptoms of glaucoma?
At first, open-angle
glaucoma has no symptoms. Vision stays normal, and there is no pain. As
glaucoma remains untreated, people may notice that although they see things
clearly in front of them, they miss objects to the side and out of the
corner of their eye.
people with glaucoma may find that they suddenly have no side vision.
It may seem as though they are looking through a tunnel. Over time, the
remaining forward vision may decrease until there is no vision left.
How is glaucoma detected?
Most people think
that they have glaucoma if the pressure in their eye is increased. This
is not always true. High pressure puts you at risk for glaucoma. It may
not mean that you have the disease.
Whether or not you
get glaucoma depends on the level of pressure that your optic nerve can
tolerate without being damaged. This level is different for each person.
View of boys by person with normal vision.
View of boys by person with glaucoma.
Although normal pressure
is usually between 12-21 mm Hg, a person might have glaucoma even if the
pressure is in this range. That is why an eye examination is very important.
To detect glaucoma, your eye care professional will do the following tests:
Visual acuity: This eye chart test measures how well you see at various distances.
This test measures your side (peripheral) vision. It helps your eye
care professional find out if you have lost side vision, a sign of glaucoma.
This examination provides your eye care professional with a better view
of the optic nerve to check for signs of damage. To do this, your eye
care professional places drops into the eye to dilate (widen) the pupil.
After the examination, your close-up vision may remain blurred for several
This standard test determines the fluid pressure inside the eye. There
are many types of tonometry. One type uses a purple light to measure
pressure. Another type is the "air puff," test, which measures
the resistance of the eye to a puff of air.
Can glaucoma be treated?
Yes. Although you
will never be cured of glaucoma, treatment often can control it. This
makes early diagnosis and treatment important to protect your sight. Most
doctors use medications for newly diagnosed glaucoma; however, new research
findings show that laser surgery is a safe and effective alternative.
Medicines are the most common early treatment for glaucoma. They come
in the form of eyedrops and pills. Some cause the eye to make less fluid.
Others lower pressure by helping fluid drain from the eye.
Glaucoma drugs may
be taken several times a day. Most people have no problems. However, some
medicines can cause headaches or have side effects which affect other
parts of the body. Drops may cause stinging, burning, and redness in the
eye. Ask your eye care professional to show you how to put the drops into
your eye. In addition, tell your eye care professional about other medications
you may be taking before you begin glaucoma treatment.
Many drugs are available
to treat glaucoma. If you have problems with one medication, tell your
eye care professional. Treatment using a different dosage or a new drug
may be possible.
You will need to
use the drops and/or pills as long as they help to control your eye pressure.
This is very important. Because glaucoma often has no symptoms,
people may be tempted to stop or may forget to take their medicine.
(also called laser trabeculoplasty): Laser surgery helps fluid drain
out of the eye. Although your eye care professional may suggest laser
surgery at any time, it is often done after trying treatment with medicines.
In many cases, you will need to keep taking glaucoma drugs even after
Laser surgery is
performed in an eye care professional's office or eye clinic. Before the
surgery, your eye care professional will apply drops to numb the eye.
As you sit facing
the laser machine, your eye care professional will hold a special lens
to your eye. A high-energy beam of light is aimed at the lens and reflected
onto the meshwork inside your eye. You may see flashes of bright green
or red light. The laser makes 50-100 evenly spaced burns. These burns
stretch the drainage holes in the meshwork. This helps to open the holes
and lets fluid drain better through them.
Your eye care professional
will check your eye pressure shortly afterward. He or she may also give
you some drops to take home for any soreness or swelling inside the eye.
You will need to make several followup visits to have your pressure monitored.
Once you have had
laser surgery over the entire meshwork, further laser treatment may not
help. Studies show that laser surgery is very good at getting the pressure
down. But its effects sometimes wear off over time. Two years after laser
surgery, the pressure increases again in more than half of all patients.
The purpose of surgery is to make a new opening for the fluid to leave
the eye. Although your eye care professional may suggest it at any time,
this surgery is often done after medicine and laser surgery have failed
to control your pressure.
Surgery is performed
in a clinic or hospital. Before the surgery, your eye care professional
gives you medicine to help you relax and then small injections around
the eye to make it numb.
eye care professional removes a small piece of tissue from the white
(sclera) of the eye. This creates a new channel for fluid to drain
from the eye. But surgery does not leave an open hole in the eye.
The white of the eye is covered by a thin, clear tissue called the
conjunctiva. The fluid flows through the new opening, under the conjunctiva,
and drains from the eye.
You must put
drops in the eye for several weeks after the operation to fight
infection and swelling. (The drops will be different than the eyedrops
you were using before surgery.) You will also need to make frequent
visits to your eye care professional. This is very important, especially
in the first few weeks after surgery.
In some patients,
surgery is about 80 to 90 percent effective at lowering pressure.
However, if the new drainage opening closes, a second operation
may be needed. Conventional surgery works best if you have not had
previous eye surgery, such as a cataract operation.
Keep in mind
that while glaucoma surgery may save remaining vision, it does not
improve sight. In fact, your vision may not be as good as it was
any operation, glaucoma surgery can cause side effects. These include
cataract, problems with the cornea, inflammation or infection inside the
eye, and swelling of blood vessels behind the eye. However, if you do
have any of these problems, effective treatments are available.
What are some other forms of glaucoma?
glaucoma is the most common form, some people have other forms of the
or normal-tension glaucoma, optic nerve damage and narrowed side
vision occur unexpectedly in people with normal eye pressure. People
with this form of the disease have the same types of treatment as open-angle
glaucoma, the fluid at the front of the eye cannot reach the angle
and leave the eye because the angle gets blocked by part of the iris.
People with this type of glaucoma have a sudden increase in pressure.
Symptoms include severe pain and nausea as well as redness of the eye
and blurred vision. This is a medical emergency. The patient
needs immediate treatment to improve the flow of fluid. Without treatment,
the eye can become blind in as little as one or two days. Usually, prompt
laser surgery can clear the blockage and protect sight.
glaucoma, children are born with defects in the angle of the eye
that slow the normal drainage of fluid. Children with this problem usually
have obvious symptoms such as cloudy eyes, sensitivity to light, and
excessive tearing. Surgery is usually the suggested treatment, because
medicines may have unknown effects in infants and be difficult to give
to them. The surgery is safe and effective. If surgery is done promptly,
these children usually have an excellent chance of having good vision.
can develop as a complication of other medical conditions. They are
sometimes associated with eye surgery or advanced cataracts, eye injuries,
certain eye tumors, or uveitis (eye inflammation). One type, known as
pigmentary glaucoma, occurs when pigment from the iris flakes off and
blocks the meshwork, slowing fluid drainage. A severe form, called neovascular
glaucoma, is linked to diabetes. Also, corticosteroid drugsused
to treat eye inflammations and other diseases--can trigger glaucoma
in a few people. Treatment is with medicines, laser surgery, or conventional
What research is being done?
The National Eye
Institute (NEI) is the Federal government's lead agency for vision research.
The NEI is supporting many research studies both in the laboratory and
with patients. This research should provide better ways in the future
to detect, treat, and prevent vision loss in people with glaucoma.
For instance, researchers
recently found a gene that causes a form of glaucoma that starts at a
young age. This is the first glaucoma gene ever located. This finding
could help us learn more about how glaucoma damages the eye.
The NEI is also supporting
clinical studies that will tell us more about who is likely to get glaucoma,
when to treat people with increased pressure, and which treatment to use
What can you do to protect your vision?
If you are being
treated for glaucoma, be sure to take your glaucoma medicine every day
and see your eye care professional regularly.
You can also help
protect the vision of family members and friends who may be at high risk
for glaucoma--Blacks over age 40 and everyone over age 60. Encourage
them to have an eye examination through dilated pupils every two years.
For more information
about glaucoma, you may wish to contact:
American Academy of Ophthalmology
655 Beach Street
San Francisco, CA 94109-7424
American Optometric Association
243 Lindbergh Boulevard
St. Louis, MO 63141
(The) Glaucoma Foundation
33 Maiden Lane
New York, NY 10038
Glaucoma Research Foundation
200 Pine Street, Suite 200
San Francisco, CA 94104
National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
Prevent Blindness America
500 East Remington Road
Schaumburg, IL 60173
1 (800) 331 -2020