 Glaucoma
Glaucoma is the name given to a group of eye conditions which cause damage to the optic nerve. The optic nerve carries sight images from the eye to the brain. If untreated, glaucoma will cause partial or total loss of sight. In general, glaucoma occurs when the pressure inside the eyeball (theintraocular pressure) increases. This pressure causes slow and steady damage to the optic nerve. As the optic nerve is slowly damaged, blind areas develop. These blind areas can cause a loss of vision or even total blindness, usually painlessly.
Open-angle glaucoma Normally the fluid in the anterior chamber drains out through the "angle" where the iris meets the cornea. In open-angle glaucoma, the "angle" is open, but for some reason the pathway is damaged or clogged. Open angle glaucoma affects all races, but the highest incidence is in African-Americans. The incidence increases with age. Because the pressure inside the eye rises slowly, there are no symptoms and the disease often is undetected until vision is impaired. Once vision is lost, it cannot be recovered. Angle closure glaucoma Angle closure glaucoma occurs when something causes a sudden blockage of the angle, preventing the fluid from draining out. This type of glaucoma is more common in farsighted people, because the anterior chamber is usually smaller than average, and therefore the angle is smaller. This can occur quickly, as in acute angle closure glaucoma. In acute angle closure glaucoma, the pressure rises quickly, over a matter of hours. The eye becomes painful and red, and a person may see haloes around lights and have blurred vision. Damage to the optic nerve can occur quickly, and this type of glaucoma should be treated as an emergency. At the front of the eye, there is a small space called the anterior chamber. A clear fluid called aqueous fills the anterior chamber. This fluid normally flows easily in and out of the chamber to bathe and nourish nearby tissues in the eye. However, in someone with glaucoma, the fluid drains out too slowly. As more fluid is made, it builds up and the fluid pressure inside the eye rises. Think of it as a clogged sink. If the water drains too slowly through the clog, the water accumulates in the sink and eventually overflows if the faucet is left on. To keep this from happening, you can unclog the drain to let the water flow out, or you can turn off the faucet. Unless the pressure is controlled (i.e., the drain is unclogged) it can pinch the optic nerve and cause damage. This can cause someone who has glaucoma to eventually go blind.
At first, there are no symptoms. Vision stays normal, and there is no pain. However, by
the time glaucoma has caused severe damage, the affected person may notice that
their side vision is gradually failing. This means that objects in the front may still be
seen clearly, but objects to the side may be missed. As glaucoma worsens, the field
of vision narrows and blindness results. Glaucoma is a leading cause of blindness in the United States. More than two million people in America have glaucoma. Recent studies show that of those people, glaucoma is eight times more common in African-Americans than in Caucasians. By the age of 70, 1 in 50 Caucasians will develop glaucoma. In African-Americans, the rate is 1 in 8. Also, a number of studies indicate that if a person's immediate family (i.e., parents, grandparents, brothers, and sisters) has glaucoma, that person is at greater risk of developing the disease. Although glaucoma can strike at any time, some people are at higher risk. They include:
Regardless of the rate of occurrence, glaucoma appears to be a more aggressive
disease in African-Americans.
Routine eye exams are important to check the eye pressure, but this alone
cannot detect glaucoma. Glaucoma is found most often during eye examination through
dilated pupils. This means that drops are put into the eyes to enlarge the pupils and
allow the doctors to see the back of the eye. Visual field measurements are sometimes also
used to check the progression of vision loss.
Although open-angle glaucoma cannot be cured, it can usually be controlled. Treatment of glaucoma is for the rest of one's life. Sometimes it's hard for patients to see the benefit of treatment, especially since nothing improves. The goal is not improvement, but prevention of further damage to the eye. If the eye pressure is not controlled, the optic nerve will be damaged and vision will be lost. Vision lost to glaucoma cannot be recovered. Treatment usually starts out with drops or pills which can reduce the intraocular pressure. Some medications are designed to reduce pressure by slowing the flow of fluid into the eye. Others help improve fluid drainage. For most people with glaucoma, regular use of medications will control the increased fluid pressure. If these medications stop working over time or cause side effects, the doctor may change the dosage or select another medication to control the glaucoma. Sometimes laser treatment is used. During laser treatment, a strong beam of light is focused on the part of the anterior chamber where the fluid leaves the eye. This makes it easier for fluid to drain out of the eye. Over time, the effect of this laser treatment may wear off. Patients who have this form of treatment may need to keep taking glaucoma medications. Surgery can also help fluid drain from the eye, and this will relieve the pressure. However, surgery is usually a last step, reserved for patients whose eye pressure cannot be controlled with drops, pills, or laser treatment. What can you do to protect your vision? Studies have shown that early detection and treatment of glaucoma, before it causes major vision loss, is the best way to control the disease. So, if you fall into one of the high-risk groups for the disease, please make sure to have your eyes examined through dilated pupils at least every other year. Glaucoma is usually a lifelong problem. Never assume that you have been cured, and do not stop treatment unless you have been told to do so. Left untreated, glaucoma can cause total blindness. On the other hand, proper treatment and regular check-ups can help you preserve your eyesight for the rest of your life. Many doctors are now starting to believe that there is more to glaucoma than just high fluid pressure inside the eye. They now feel that the other factor that causes vision loss is poor blood flow (circulation) to the optic nerve. Therefore, anything which improves overall circulation would also be helpful in fighting glaucoma. A diet low in fat and high in vegetables, fruits, and complex carbohydrates would be helpful in improving blood flow. Fatty foods, which inhibit good blood flow, should be avoided. Other conditions, such as high blood pressure and diabetes, should be controlled to help improve blood flow to the optic nerve. Other factors which may help include exercise and not smoking.
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What is Glaucoma?
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