Cataract surgery improves vision in almost every case
DEAR DOCTOR K:
I have cataracts. What are my treatment options?
"Cataract" means "huge waterfall." And that's how some people with cataracts describe their clouded sight -- like trying to look through a waterfall.
Light enters our eyes and then passes through the lens, a structure inside the eye. The job of the lens, like the lens of a camera, is to focus images. With a digital camera, the lens focuses images on a light-sensitive plate. With our eyes, the lens focuses images on a little light-sensitive "wall" in the back of the eye, the retina. The focused image is then sent by the retina to the brain. That's when we see things.
A healthy lens is clear, so that light can pass through it without being distorted. Cataracts are cloudy areas in the lens. At first, you don't notice them because they don't affect your vision. Your doctor might see them during an eye examination. It's not uncommon for me to see that a patient of mine is developing cataracts, but doesn't know it. Over time, however, the cloudy areas gradually get larger and interfere with vision. They distort or block the passage of light through the lens.
Cataracts can occur in one eye or both. If they affect both eyes, they often proceed at a different pace: They may be more advanced in one eye than in the other.
Cataracts are a long-term problem, and in most patients, vision gets worse over time. You may be able to improve your vision by using eyeglasses, magnifying lenses or stronger lighting. However, if cataracts get bad enough in one eye, they can affect depth perception. That, in turn, makes driving hazardous and sports difficult.
If the cataracts get bad enough in both eyes, they can lead to blindness if not treated.
The only way to cure cataracts is to remove the clouded lenses and replace them with a clear plastic lens. Compared to when I was in medical school, cataract surgery today is much simpler and more effective.
There are two surgical options for taking out the cloudy lenses. The first is called extracapsular cataract extraction. In this procedure, most of the cataract may be removed manually. Or, sound waves may be used to break the clouded lens into tiny pieces, which are then vacuumed out. The capsule surrounding the lens is left intact.
In the other surgical procedure, known as intracapsular cataract extraction, both the lens and the lens capsule are removed.
Once the cloudy lens is out, you can have a clear plastic lens placed in the eye, or you can wear a contact lens or special cataract glasses with very powerful magnification.
Cataract surgery improves vision in the vast majority of patients who have it. In some people who have extracapsular surgery, part of the lens capsule may eventually become cloudy. This can be corrected with laser surgery.
You cannot prevent age-related cataracts. But you can lower your risk by limiting your time in the bright sun, not smoking and controlling your blood sugar if you have diabetes.
(Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.)
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