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Diabetic Eye
Care |
Diabetic Eye Disease
Diabetes is the leading cause of
blindness in working-age Americans
Approximately 29 million Americans age 20 or
older have diabetes. But many, almost
one-third, don't know they have the disease
and are at risk for vision loss and other
health problems.
Diabetic eye disease, a group of eye
problems that affects those with diabetes,
includes diabetic retinopathy, cataracts and
glaucoma. The most common of these is
diabetic retinopathy, which affects 5.3
million Americans age eighteen and older.
Diabetic retinopathy is a potentially
blinding condition in which the blood
vessels inside the retina become damaged
from the high blood sugar levels associated
with diabetes. This leads to the leakage of
fluids into the retina and the obstruction
of blood flow. Both may cause vision loss.
More than one-third of those diagnosed with
diabetes do not receive the recommended
vision care and are at risk for blindness.
Often early symptoms are unnoticed,
therefore your vision may not be affected
until the disease is severe and less easily
treatable.
Once you are diagnosed with diabetes,
schedule a complete dilated eye examination
with your Eye M.D. at least once a year.
Make an appointment promptly if you
experience blurred vision and/or floaters
that:
* Affect only one eye
* Last more than a few days
* Are not associated with a change in blood
sugar
In advanced cases of diabetic retinopathy,
laser treatment has been shown to reduce the
chance of severe vision loss and blindness.
This surgery does not cure diabetic
retinopathy or restore vision that has
already been lost, nor does it prevent
future vision loss, especially if diabetes
or blood pressure is not well controlled.
Diabetes can also affect your vision by
causing cataracts and glaucoma. If you have
diabetes, you may get cataracts at a younger
age and your chances of developing glaucoma
are doubled.
Early diagnosis of diabetes and most
importantly, maintaining strict control of
blood sugar and hypertension through diet,
exercise and medication can help to reduce
your risk of developing eye diseases
associated with diabetes.
Diabetes Can Affect Sight
If you have diabetes mellitus, your body
does not use and store sugar properly. High
blood-sugar levels can damage blood vessels
in the retina, the nerve layer at the back
of the eye that senses light and helps to
send images to the brain. The damage to
retinal vessels is referred to as diabetic
retinopathy.
Types of
Diabetic Retinopathy
There are two types of diabetic retinopathy:
nonproliferative diabetic
retinopathy
(NPDR) and
proliferative diabetic retinopathy
(PDR).
NPDR,
commonly known as
background retinopathy,
is an early stage of diabetic retinopathy.
In this stage, tiny blood vessels within the
retina leak blood or fluid. The leaking
fluid causes the retina to swell or to form
deposits called
exudates.
Many people with diabetes have mild NPDR,
which usually does not affect their vision.
When vision is affected it is the result of
macular edema
and/or
macular ischemia.
* Macular
edema is
swelling or thickening of the
macula,
a small area in the center of the retina
that allows us to see fine details clearly.
The swelling is caused by fluid leaking from
retinal blood vessels. It is the most common
cause of visual loss in diabetes. Vision
loss may be mild to severe, but even in the
worst cases, peripheral vision continues to
function.
* Macular
ischemia
occurs when small blood vessels
(capillaries) close. Vision blurs because
the macula no longer receives sufficient
blood supply to work properly.
PDR
is present when abnormal new vessels (neovascularization)
begin growing on the surface of the retina
or optic nerve. The main cause of PDR is
widespread closure of retinal blood vessels,
preventing adequate blood flow. The retina
responds by growing new blood vessels in an
attempt to supply blood to the area where
the original vessels closed.
Unfortunately, the new, abnormal blood
vessels do not resupply the retina with
normal blood flow. The new vessels are often
accompanied by scar tissue that may cause
wrinkling or detachment of the retina.
PDR may cause more severe vision loss than
NPDR because it can affect both central and
peripheral vision.
Proliferative diabetic retinopathy causes
visual loss in the following ways:
Vitreous
hemorrhage:
The fragile new vessels may bleed into the
vitreous, a clear, gel-like substance that
fills the center of the eye. If the vitreous
hemorrhage is small, a person might see only
a few new dark floaters. A very large
hemorrhage might block out all vision.
It may take days, months, or even years to
resorb the blood, depending on the amount of
blood present. If the eye does not clear the
vitreous blood adequately within a
reasonable time, vitrectomy surgery may be
recommended.
Vitreous hemorrhage alone does not cause
permanent vision loss. When the blood
clears, vision may return to its former
level unless the macula is damaged.
Traction
retinal detachment:
When PDR is present, scar tissue associated
with neovascularization can shrink,
wrinkling and pulling the retina from its
normal position. Macular wrinkling can cause
visual distortion. More severe vision loss
can occur if the macula or large areas of
the retina are detached.
Neovascular glaucoma:
Occasionally, extensive retinal vessel
closure will cause new, abnormal blood
vessels to grow on the
iris
(colored part of the eye) and block the
normal flow of fluid out of the eye.
Pressure in the eye builds up, resulting in
neovascular glaucoma,
a severe eye disease that causes damage to
the optic nerve.
How is
diabetic retinopathy diagnosed?
A medical eye examination is the only way to
detect changes inside your eye. Our
ophthalmologists can often
diagnose and treat serious retinopathy
before you are aware of any vision problems.
The ophthalmologist dilates your pupil and
looks inside of the eye with an
ophthalmoscope.
If your ophthalmologist finds diabetic
retinopathy, he may order color
photographs of the retina or a special test
called
fluorescein angiography
to find out if you need treatment. In this
test a dye is injected into your arm and
photos of your eye are taken to detect where
fluid is leaking. Click here to read
more about the FA test.
How is
diabetic retinopathy treated?
The best treatment is to prevent the
development of retinopathy as much as
possible. Strict control of your blood sugar
will significantly reduce the long-term risk
of vision loss from diabetic retinopathy. If
high blood pressure and kidney problems are
present, they need to be treated.
Laser
surgery:
Laser surgery is often recommended for
people with macular edema, PDR, and
neovascular glaucoma.
For macular edema, the laser is focused on
the damaged retina near the macula to
decrease the fluid leakage. The main goal of
treatment is to prevent further loss of
vision. It is uncommon for people who have
blurred vision from macular edema to recover
normal vision, although some may experience
partial improvement. A few people may see
the laser spots near the center of their
vision following treatment. The spots
usually fade with time but may not
disappear.
For PDR, the laser is focused on all parts
of the retina except the macula. This
panretinal photocoagulation treatment causes
abnormal new vessels to shrink and often
prevents them from growing in the future. It
also decreases the chance that vitreous
bleeding or retinal distortion will occur.
Multiple laser treatments over time are
sometimes necessary. Laser surgery does not
cure diabetic retinopathy and does not
always prevent further loss of vision.
Vitrectomy:
In advanced PDR, the ophthalmologist may
recommend a vitrectomy. During this
microsurgical procedure, which is performed
in the operating room, the blood-filled
vitreous is removed and replaced with a
clear solution. The ophthalmologist may wait
for several months or up to a year to see if
the blood clears on its own before
performing a vitrectomy.
Vitrectomy often prevents further bleeding
by removing the abnormal vessels that caused
the bleeding. If the retina is detached, it
can be repaired during the vitrectomy
surgery. Surgery should usually be done
early because macular distortion or traction
retinal detachment will cause permanent
visual loss. The longer the macula is
distorted or out of place, the more serious
the vision loss will be.
Vision
Loss Is Largely Preventable
If you have diabetes, it is important to
know that today, with improved methods of
diagnosis and treatment, only a small
percentage of people who develop retinopathy
have serious vision problems. Early
detection of diabetic retinopathy is the
best protection against loss of vision.
You can significantly lower your risk of
vision loss by maintaining strict control of
your blood sugar and visiting your
ophthalmologist regularly.
When to
Schedule an Examination
People with diabetes should schedule
examinations at least once a year. More
frequent medical eye examinations may be
necessary after a diagnosis of diabetic
retinopathy.
Pregnant women with diabetes should schedule
an appointment in the first trimester
because retinopathy can progress quickly
during pregnancy.
If you need to be examined for eyeglasses,
it is important that your blood sugar be
consistently under control for several days
when you see your ophthalmologist.
Eyeglasses that work well when the blood
sugar is out of control will not work well
when the blood sugar is stable.
Rapid changes in blood sugar can cause
fluctuating vision in both eyes even if
retinopathy is not present.
You should have your eyes checked promptly
if you have visual changes that:
* affect only one eye;
* last more than a few days;
* are not associated with a change in blood
sugar.
When you are first diagnosed with diabetes,
you should have your eyes checked:
* within five years of the diagnosis if you
are 29 years old or younger;
* within a few months of the diagnosis if
you are 30 years old and older.
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