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Glaucoma is a group of
diseases that can lead to damage to the eye's optic nerve and result in
blindness. It has no symptoms at first. But over the years it can steal your sight. With early treatment, you can often protect your eyes against serious vision loss and blindness. |
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How does glaucoma damage
the optic nerve? What are the symptoms of glaucoma? What are some other forms of glaucoma? Who is at risk? How is glaucoma detected? Can glaucoma be treated? |
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| In many people, increased pressure inside the eye causes glaucoma. In the front of the eye is a space called the anterior chamber. A clear fluid flows continuously in and out of this space and nourishes nearby tissues. | |
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The fluid leaves the anterior chamber at the 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. |
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Open-angle glaucoma
gets its name because the angle that allows fluid to drain out of the
anterior chamber is open. Blacks over age 40.
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. Without treatment, 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. 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. |
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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.
Visual acuity: This eye chart test measures how well you see at various distances. Tonometry: 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. Pupil dilation: 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 hours. Visual Field: 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. 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. Medicine:
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.
But most lower pressure by helping fluid drain from the eye. 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.
Laser surgery 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. 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 follow up visits to have your pressure monitored. Conventional
surgery: 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.
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 before surgery.
What
are some other forms of glaucoma? In low-tension 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. In closed-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. In congenital 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. |
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The
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 eye drops
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.|
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