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Cataract Fact Book
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What is the lens?
What is a cataract?
What are the symptoms?
What are the different types of cataract?
How is a cataract detected?
How is it treated?
Is cataract surgery effective?
How is a cataract removed?
What happens before surgery?
What happens during surgery?
What happens after surgery?
When will my vision be normal again?
What is an "after-cataract"?
What can you do to protect your vision?
Keeping on Top of Your Condition
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catarac
Information for Patients
A cataract is a clouding of the eye's lens that can cause vision
problems. The most common type is related to aging. More than half
of all Americans age 65 and older have a cataract.
In the early stages, stronger lighting and eyeglasses may lessen
vision problems caused by cataracts. At a certain point, however,
surgery may be needed to improve vision. Today, cataract surgery is
safe and very effective.
The lens is the part of the eye that helps focus light on
the retina. The retina is the eye's light-sensitive layer
that sends visual signals to the brain. In a normal eye, light
passes through the lens and gets focused on the retina. To help
produce a sharp image, the lens must remain clear.
The lens is made mostly of water and protein. The protein is
arranged to let light pass through and focus on the retina.
Sometimes some of the protein clumps together. This can start to
cloud small areas of the lens, blocking some light from reaching the
retina and interfering with vision. This is a cataract.
In its early stages, a cataract may not cause a problem. The
cloudiness may affect only a small part of the lens. However, over
time, the cataract may grow larger and cloud more of the lens,
making it harder to see. Because less light reaches the retina, your
vision may become dull and blurry. A cataract won't spread from one
eye to the other, although many people develop cataracts in both
eyes.
Although researchers are learning more about cataracts, no one
knows for sure what causes them. Scientists think there may be
several causes, including smoking, diabetes, and excessive exposure
to sunlight.
The most common symptoms of a cataract are:
- Cloudy or blurry vision.
- Problems with light. These can include headlights that seem
too bright at night; glare from lamps or very bright sunlight; or
a halo around lights.
- Colors that seem faded.
- Poor night vision.
- Double or multiple vision (this symptom often goes away as the
cataract grows).
- Frequent changes in your eyeglasses or contact lenses.
These symptoms can also be a sign of other eye problems. If you
have any of these symptoms, check with your eye care
professional.
When a cataract is small, you may not notice any changes in your
vision. Cataracts tend to grow slowly, so vision gets worse
gradually. Some people with a cataract find that their close-up
vision suddenly improves, but this is temporary. Vision is likely to
get worse again as the cataract grows.
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- Age-related cataract: Most cataracts are related to
aging.
- Congenital cataract: Some babies are born with
cataracts or develop them in childhood, often in both eyes. These
cataracts may not affect vision. If they do, they may need to be
removed.
- Secondary cataract: Cataracts are more likely to
develop in people who have certain other health problems, such as
diabetes. Also, cataracts are sometimes linked to steroid use.
- Traumatic cataract: Cataracts can develop soon after an
eye injury, or years later.
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To detect a cataract,
an eye care professional examines the lens. A comprehensive eye
examination usually includes:
- Visual acuity test: This eye chart test measures how
well you see at various distances.
- Pupil dilation: The pupil is widened with eyedrops to
allow your eye care professional to see more of the lens and
retina and look for other eye problems.
- Tonometry: This is a standard test to measure fluid
pressure inside the eye. Increased pressure may be a sign of
glaucoma.
Your eye care professional may also do other tests to learn more
about the structure and health of your eye.
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For an early
cataract, vision may improve by using different eyeglasses,
magnifying lenses, or stronger lighting. If these measures don't
help, surgery is the only effective treatment. This treatment
involves removing the cloudy lens and replacing it with a substitute
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 that
decision together. In most cases, waiting until you are ready to
have cataract surgery will not harm your eye. If you decide on
surgery, your eye care professional may refer you to a specialist to
remove the cataract. If you have cataracts in both eyes, the doctor
will not remove them both at the same time. You will need to have
each done separately.
Sometimes, a cataract should be removed even if it doesn't 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.
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Cataract removal is
one of the most common operations performed in the U.S. today. It is
also one of the safest and most effective. In about 90 percent of
cases, people who have cataract surgery have better vision
afterward.
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There are two primary
ways to remove a cataract. Your doctor can explain the differences
and help determine which is best for you:
- Phacoemulsification, or phaco. Your doctor makes a
small incision on the side of the cornea, the clear,
dome-shaped surface that covers the front of the eye. The doctor
then inserts a tiny probe into the eye. This device emits
ultrasound waves that soften and break up the cloudy center of the
lens so it can be removed by suction. Most cataract surgery today
is done by phaco, which is also called small incision cataract
surgery.
- Extracapsular surgery. Your doctor makes a slightly
longer incision on the side of the cornea and removes the hard
center of the lens. The remainder of the lens is then removed by
suction.
In most cataract surgeries, the removed lens is replaced by an
intraocular lens (IOL). An IOL is a clear, artificial lens
that requires no care and becomes a permanent part of your eye. With
an IOL, you'll have improved vision because light will be able to
pass through it to the retina. Also, you won't feel or see the new
lens.
Some people cannot have an IOL. They may have problems during
surgery, or maybe they have another eye disease. For these people, a
soft contact lens may be suggested. For others, glasses that provide
powerful magnification may be better.
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A week or two before surgery, your eye care professional will do
some tests. These may include tests to measure the curve of the
cornea and the size and shape of the eye. For patients who will
receive an IOL, this information helps your doctor choose the right
type of IOL. Also, doctors may ask you not to eat or drink anything
after midnight the morning of your surgery.
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When you enter the hospital or clinic, you will be given eye
drops to dilate the pupil. The area around your eye will be washed
and cleansed.
The operation usually lasts less than 1 hour and is almost
painless. Many people choose to stay awake during surgery, while
others may need to be put to sleep for a short time. If you are
awake, you will have an anesthetic to numb the nerves in and around
your eye.
After the operation, a patch will be placed over your eye and you
will rest for a while. You will be watched by your medical team to
see if there are any problems, such as bleeding. Most people who
have cataract surgery can go home the same day. Since you will not
be able to drive, make sure you make arrangements for a ride.
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It's normal to feel
itching and mild discomfort for a while after cataract surgery. Some
fluid discharge is also common, and your eye may be sensitive to
light and touch. If you have discomfort, your eye care professional
may suggest a pain reliever every 4-6 hours. After 1-2 days, even
moderate discomfort should disappear. In most cases, healing will
take about 6 weeks.
After surgery, your doctor will schedule exams to check on your
progress. For a few days after surgery, you may take eyedrops or
pills to help healing and control the pressure inside your eye. Ask
your doctor how to use your medications, when to take them, and what
effects they can have. You will also need to wear an eye shield or
eyeglasses to help protect the eye. Avoid rubbing or pressing on
your eye.
Problems after surgery are rare, but they can occur. These can
include infection, bleeding, inflammation (pain, redness, swelling),
loss of vision, or light flashes. With prompt medical attention,
these problems usually can be treated successfully.
When you are home, try not to bend or lift heavy objects. Bending
increases pressure in the eye. You can walk, climb stairs, and do
light household chores.
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You can quickly return to many everyday activities, but your
vision may be blurry. The healing eye needs time to adjust so that
it can focus properly with the other eye, especially if the other
eye has a cataract. Ask your doctor when you can resume driving.
If you just received an IOL, you may notice that colors are very
bright or have a blue tinge. Also, if you've been in bright
sunlight, everything may be reddish for a few hours. If you see
these color tinges, it is because your lens is clear and no longer
cloudy. Within a few months after receiving an IOL, these colors
should go away. And when you have healed, you will probably need new
glasses.
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Sometimes a part of the natural lens that is not removed during
cataract surgery becomes cloudy and may blur your vision. This is
called an after-cataract. An after-cataract can develop
months or years later.
Unlike a cataract, an after-cataract is treated with a laser. In
a technique called YAG laser capsulotomy, your doctor uses a
laser beam to make a tiny hole in the lens to let light pass
through. This is a painless outpatient procedure.
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Although we don't know how to protect against cataracts, people
over the age of 60 are at risk for many vision problems. If you are
age 60 or older, you should have an eye examination through dilated
pupils at least every 2 years. This kind of exam allows your eye
care professional to check for signs of age-related macular
degeneration, glaucoma, cataracts, and other vision disorders.
Keeping on Top of Your Condition
Keeping in tune with your disease or condition not only makes treatment less intimidating but also increases its chance of success, and has been shown to lower a patients risk of complications. As well, as an informed patient, you are better able to discuss your condition and treatment options with your physician.
A new service available to patients provides a convenient means of staying informed, and ensures that the information is both reliable and accurate. If you wish to find out more about HealthNewsflash's innovative service, take the tour.
For more information about cataracts, you may wish to contact:
Agency for Health Care Policy and Research Publications
Clearinghouse
P.O. Box 8547
Silver Spring, MD 20907
1-800-358-9295
(410) 381-3150
http://www.ahcpr.gov
American Academy of Ophthalmology
655 Beach Street
San Francisco, CA 94109-7424
(415) 561-8500
http://www.aao.org
American Optometric Association
243 Lindbergh
Boulevard
St. Louis, MO 63141
(314) 991-4100
http://www.aoanet.org
National Eye Institute
2020 Vision Place
Bethesda,
MD 20892-3655
(301) 496-5248
http://www.nei.nih.gov
Prevent Blindness America
500 East Remington Road
Schaumburg, IL 60173
1-800-331-2020
(847) 843-2020
http://www.preventblindness.org
For more information about IOLs, contact:
U.S. Food and Drug Administration
Office of Consumer
Affairs
Parklawn Building (HFE-88)
5600 Fishers Lane
Rockville, MD 20857
1-888-463-6332
http://www.fda.gov
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