Eye Diseases and Disorders Series - LPR Staff Project
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The following article is provided courtesy of the National Eye Institute. Printed copies of this article, as well as a complete list of free publications offered by the NEI can be found on their NEI Publications Catalog.
This article is for information purposes only. Always consult your doctor for medical advice.
This pamphlet has been written
to help people with cataracts
and their families better
understand the condition. It
describes the symptoms,
diagnosis, and treatment of
cataracts.
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.
What is the lens?
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.
What is a cataract?
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.
What are the
symptoms?
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.
What are the
different types of
cataract?
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.
How is a cataract
detected?
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.
How is it treated?
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.
Is cataract surgery
effective?
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.
How is a cataract
removed?
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.
What happens before
surgery?
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.
What happens during
surgery?
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.
What happens after
surgery?
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.
When will my vision
be normal again?
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.
What is an
"after-cataract"?
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.
What research is
being done?
The NEI is conducting and
supporting a number of studies,
such as the Age-Related Eye
Disease Study (AREDS). In this
nationwide clinical study,
scientists are examining how
cataracts develop and what
factors put people at risk for
developing them. Also, they are
looking at whether certain
vitamins prevent or delay
cataract development.
Other research is focusing on
new ways to prevent, diagnose,
and treat cataracts. In addition,
scientists are studying the role of
genetics in the development of
cataracts.
What can you do to
protect your vision?
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.
Links to articles about, and varied information on, cataracts. Includes links to information on treatment, medication, prevention, and detection of cataracts, as well as pictures of cataracts.
Information about the latest research on cataracts, as well as information on the latest surgical and non-surgical treatment options for the treatment of cataracts.
eMedicine.com has some very detailed information on Cataracts. This information is extremely technical and is definitely geared toward members of the medical establishment - but don't let this put you off. All these articles are peer reviewed and they represent an excellent resource. They also provide information that you may not be able to find elsewhere.
The Eye Book: A Complete Guide to Eye Disorders and Health, By Gary H. Cassel, Michael D. Billig, and Harry G. Randall.
A comprehensive resource for information related to the eye; this book provides a general overview of eye health and anatomy, and common eye disorders.