What is glaucoma?
Glaucoma is an eye disease in which the normal fluid pressure inside the eye slowly rises, leading to vision loss - or even blindness. This is about open - angle glaucoma, the most common form of the disease.
What causess glaucoma?
At the front of the eye, there is a small space called the anterior chamber. Clear fluid flows in and out of the chamber to bathe and nourish nearby tissues. In glaucoma, for still unknown reasons, the fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye rises. Unless this pressure is controlled, it may cause damage to the optic nerve and other parts of the eye and loss of vision.
Who is at risk for glaucoma?
Nearly 3 million people have glaucoma, a leading cause of blindness in the United States. Although anyone can get glaucoma, some people are at a higher risk. They include Blacks over the age of 40, anyone over the age of 60. people with a family history of glaucoma. Among Blacks, studies show that glaucoma is:
- Five times more likely to occur then in Whites,
- Four times more likely to cause blindness in Blacks then in Whites
- Fifteen times more likely to cause in Blacks between the ages of 45-64 then in Whites of the same age group
What are the symptoms?
At first, there are no symptoms. Vision stays normal, and there is no pain. However, as the disease progresses, a person with glaucoma may notice his or her side vision gradually failing. That is, objects in front may still be seen clearly, but objects to the side may be missing. As the disease worsens, the field of vision narrows and blindness results.
How is glaucoma detected?
Many people may know of the "air puff" test or other tests used to measure eye pressure in the eye examination. But this test alone cannot detect glaucoma. Glaucoma is found most often during an eye examination through dilated pupils. This means drops are put into the eye during the exam to enlarge the pupils. This allows the eye care professional to see more of the inside of the eye to check for signs of glaucoma.
How is glaucoma treated?
Although open-angle glaucoma cannot be cured, it can usually be controlled. The most common treatments are: Medications These may be either in the form of eyedrops or pills. Some drugs are designed to reduce pressure by slowing the flow of fluid into the eye. Others help to improve fluid drainage. For some people with glaucoma, regular use of medication will control the increased fluid pressure. But, these drugs may stop working over time. Or, they may cause side effects. If a problem occurs, the eye care professional may select other drugs, change the dose, or suggest other ways to deal with the problem. Laser surgery During laser surgery, a strong beam of light is focused on the part of the anterior chamber where the fluid leaves thee eye. This results in a series of changes, which make it easier for the fluid to exit the eye. Over time, the effect of laser surgery may wear off. Patients who have this form of surgery may need to keep taking glaucoma drugs. Surgery Surgery can also help fluid to escape from the eye and thereby reduce the pressure. However, surgery is usually reserved for patients whose pressure cannot be controlled with eyedrops, pills, or laser surgery.
What is a cataract?
A cataract is a clouding of the lens in the eye that affects vision. Most cataracts are related to aging. Cataracts are very common in older people. By age 80, more than half of all Americans either have a cataract or have had cataract surgery. A cataract can occur in either or both eyes. It cannot spread from one eye to the other.
Are there other types of cataract?
Yes. Although most cataracts are related to aging, there are other types of cataract:
- Secondary cataract. Cataracts can form after surgery for other eye problems, such as glaucoma. Cataracts also can develop in people who have other health problems, such as diabetes. Cataracts are sometimes linked to steroid use.
- Traumatic cataract. Cataracts can develop after an eye injury, sometimes years later.
- Congenital cataract. Some babies are born with cataracts or develop them in childhood, often in both eyes. These cataracts may be so small that they do not affect vision. If they do, the lenses may need to be removed.
- Radiation cataract. Cataracts can develop after exposure to some types of radiation.
The lens lies behind the iris and the pupil (see diagram). It works much like a camera lens. It focuses light onto the retina at the back of the eye, where an image is recorded. The lens also adjusts the eye's focus, letting us see things clearly both up close and far away. The lens is made of mostly water and protein. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.
But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract. Over time, the cataract may grow larger and cloud more of the lens, making it harder to see.
Researchers suspect that there are several causes of cataract, such as smoking and diabetes. Or, it may be that the protein in the lens just changes from the wear and tear it takes over the years.
How is a cataract detected?
Cataract is detected through a comprehensive eye exam that includes:
- Visual acuity test. This eye chart test measures how well you see at various distances.
- Dilated eye exam. Drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
- Tonometry. An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
How is a cataract treated?
The symptoms of early cataract may be improved with new eyeglasses, brighter lighting, anti-glare sunglasses, or magnifying lenses. If these measures do not help, surgery is the only effective treatment. Surgery involves removing the cloudy lens and replacing it with an artificial lens.
A cataract needs to be removed only when vision loss interferes with your everyday activities, such as driving, reading, or watching TV. You and your eye care professional can make this decision together. Once you understand the benefits and risks of surgery, you can make an informed decision about whether cataract surgery is right for you. In most cases, delaying cataract surgery will not cause long-term damage to your eye or make the surgery more difficult. You do not have to rush into surgery.
Sometimes a cataract should be removed even if it does not cause problems with your vision. For example, a cataract should be removed if it prevents examination or treatment of another eye problem, such as age-related macular degeneration or diabetic retinopathy. If your eye care professional finds a cataract, you may not need cataract surgery for several years. In fact, you might never need cataract surgery. By having your vision tested regularly, you and your eye care professional can discuss if and when you might need treatment.
If you choose surgery, your eye care professional may refer you to a specialist to remove the cataract.
If you have cataracts in both eyes that require surgery, the surgery will be performed on each eye at separate times, usually four to eight weeks apart.
Many people who need cataract surgery also have other eye conditions, such as age-related macular degeneration or glaucoma. If you have other eye conditions in addition to cataract, talk with your doctor. Learn about the risks, benefits, alternatives, and expected results of cataract surgery.