November is American Diabetes Month
Click
here for Diabetes Info Sheet
To
help promote awareness of Diabetic Retinopathy we are participating
in American Diabetes Month. More information about our involvement
in American Diabetes Month can be found here.
If you have diabetes find out how you can protect your vision.
Diabetes Can Affect Sight
Diabetes mellitus is a condition
which impairs the body's ability to use and store sugar. Elevated
blood-sugar levels, excessive thirst and urination, and changes
in the body's blood vessels are all characteristic of the
disease. Diabetes may affect vision by causing cataracts,
glaucoma, and most importantly, damage to blood vessels inside
the eye.
What
Is Diabetic Retinopathy?
 Diabetic
retinopathy, a complication of diabetes, is caused by changes
in the blood vessels of the retina, the light-sensitive nerve
layer in the rear of the eye. These damaged blood vessels
may leak fluid or blood, and develop fragile brush-like branches
and scar tissue. The images which the retina sends to the
brain become blurred, distorted or partially blocked.
The
risk of developing diabetic retinopathy increases the longer
the person has diabetes. About 80% of the people with at least
a 15-year history of diabetes have some blood vessel damage
to their retina.
Diabetic
retinopathy is particularly likely to occur at a younger age
in juvenile diabetics, who have been diagnosed with the condition
during their childhood or teenage years. Diabetic retinopathy
is the leading cause of new blindness among adults in the
United States, and people with untreated diabetes are said
to be 25 times more prone to blindness than the general population.
However, with improved methods of diagnosis and treatment
only a small percentage of those who develop retinopathy experience
serious problems with vision.
Types
of Diabetic Retinopathy
Background
retinopathy is an early stage of diabetic retinopathy. In
this stage, fine blood vessels within the retina become narrowed
or obstructed while others enlarge to form balloon-like sacs.
These altered vessels leak blood and fluid, causing the retina
to swell or form deposits called exudates. Sight is usually
not seriously affected. It can, however, lead to more advanced
sight-threatening stages, and for this reason is considered
a warning sign.
In
some cases, the leaking fluid collects in the macula, the
portion of the retina responsible for detailed vision, such
as reading. This problem is called macular edema. Reading
and close work may become more difficult because of this condition.
Proliferative
retinopathy describes the changes that occur when new, abnormal
blood vessels begin growing on the surface of the retina or
the optic nerve. These new blood vessels, called neovascularization,
have weaker walls and may rupture and bleed into the vitreous,
the clear gel-like substance that fills the center of the eye.
This leaking blood can cloud the vitreous and partially block
the light passing through the pupil towards the retina, causing
blurred and distorted images. These abnormal blood vessels
frequently grow scar tissue with them which may pull the retina
away from its normal position at the back of the eye (detached
retina). Abnormal blood vessels may also grow around the pupil
(on the iris) causing glaucoma by increasing pressure within
the eye. Proliferative diabetic retinopathy is the most serious
form of diabetic retinal disease. It affects up to 20% of
diabetics and can cause severe loss of sight, including blindness.
Cause
and Symptoms
The
cause of diabetic retinopathy is not completely understood;
however, it is known that diabetes damages small blood vessels
in various areas of the body. Pregnancy and high blood pressure
may aggravate diabetic retinopathy.
Although
gradual blurring of the vision may occur if macular edema
is present, sight is usually unaffected by background diabetic
retinopathy and changes in the eye can go unnoticed unless
detected by a medical eye examination. When bleeding occurs
in proliferative diabetic retinopathy, the sight may become
hazy, spotty or even disappear altogether. While there is
no pain, this severe form of diabetic retinopathy requires
immediate medical attention.
Detection
and Diagnosis
A
comprehensive medical eye examination and appropriate treatment
by an ophthalmologist is the best protection against eye damage
due to the diabetic retinopathy. Serious retinopathy can be
present without symptoms and improve with treatment. Therefore,
people with diabetes should be aware of the risks of developing
visual problems and should have their eyes examined regularly.
(Periodic eye examinations are also advisable for apparently
healthy people, because such examinations help detect the
presence of diabetes and other diseases.)
To
detect diabetic retinopathy, the ophthalmologist conducts
a painless examination of the inner part of the eye using
an instrument called an ophthalmoscope. The pupils may need
to be dilated with eye drops.
If
diabetic retinopathy is noted, the ophthalmologist may obtain
color photographs of the retina. Sometimes a specialized technique
is used which provides great detail about retinal blood vessels
and leakage. First, a fluorescent dye is injected into the
vein of the arm. The dye travels through the bloodstream,
including the blood vessels of the retina. Photographs are
taken in rapid succession as the dye passes through the retinal
blood vessels. This technique, called fluorescein angiography,
is often used by ophthalmologist to determine if further treatment
is necessary.
Treatment
 When
diabetic retinopathy is diagnosed, the ophthalmologist considers
the patient's age, history, lifestyle, and the degree of damage
to the retina before deciding whether treatment or further
observation of the disease is most appropriate. In many cases,
treatment is not necessary; in others it is recommended to
halt the damage of the diabetic retinopathy and improve the
sight wherever possible.
Laser
Surgery
The
most significant treatment is ophthalmic laser surgery, which
seals or photocoagulates the leaking blood vessels. During
this procedure, a powerful beam of laser light is focused
on the damaged retina. Small bursts of the laser's beam seal
leaking retinal vessels to reduce the macular edema. When
larger applications of the laser beam are scattered throughout
more peripheral areas of the retina, the small laser scars
reduce abnormal blood vessel growth (neovascularization) and
help bond the retina back to the eye.
Laser
surgery does not require an incision and may be performed
in the ophthalmologist's office or an outpatient clinic. If
diabetic retinopathy is detected early, photocoagulation by
laser surgery retards vision loss. Even in the more advanced
stages of the disease (proliferative retinopathy), it reduces
the chance of severe visual impairment.
Other
Treatments
If
the vitreous is clouded by hemorrhage, laser photocoagulation
cannot be used until the blood settles or clears. In some
cases of persistent vitreous hemorrhage, cryotherapy of the
retina, using local anesthesia and a cold instrument probe
may help shrink the abnormal blood vessels.
In
advanced proliferative diabetic retinopathy, the ophthalmologist
may recommend a vitrectomy. This is a microsurgical procedure,
performed in the operating room, to remove the blood-filled
vitreous and replace it with a clear solution. About 70% of
vitrectomy patients notice an improvement in sight after surgery.
 The
ophthalmologist may recommend a vitrectomy soon after the
vitreous becomes clouded by blood, or may wait from several
months up to a year to see if the blood clears on its own.
Determining the most appropriate time to perform surgery depends
on the extent of damage, as well as the condition of the other
eye. If proliferative diabetic scar tissue detaches the retina
from the back of the eye, severe sight loss or blindness can
results unless surgery is performed to reattach the retina.
Successful
treatment of diabetic retinopathy depends not only on early
detection through medical eye examinations and treatment by
an ophthalmologist, but also on the patient's attitude and
attention to medications and diet. Physical activity presents
few problems to people with background retinopathy. Occasionally,
some restriction in activity for patients with active proliferative
retinopathy is recommended.
Who
Can Treat Diabetic Retinopathy?
Only
an ophthalmologist can treat diabetic retinopathy, one aspect
of a major vascular disease affecting many parts of the body.
An ophthalmologist is a medical doctor (MD or osteopath) especially
educated, trained, and licensed to provide total care of the
eyes. This care includes performing comprehensive eye examinations,
prescribing corrective or protective lenses, diagnosing diseases
and disorders of the eye, and applying the appropriate medical
and surgical procedures necessary for their treatment.
Vision
Loss Is Largely Preventable
Early
detection of diabetic retinopathy is the best protection against
loss of vision. It is important to remember that diabetic
retinopathy may be present without any symptoms. People with
diabetes should schedule examinations by an ophthalmologist
at least once a year. More frequent medical eye examinations
may be necessary once diabetic retinopathy has been diagnosed.
In most cases, with careful monitoring, the ophthalmologist
can begin treatment before sight is affected. Modern ophthalmic
laser and operative surgical procedures are highly effective
treatment for diabetic retinopathy. If you have additional
questions or would like further information, contact your
ophthalmologist.
The
American Academy of Ophthalmology is an organization of 16,000
ophthalmologists dedicated to preserving eye health and sight.
"Diabetes 2000" is a new education program introduced
by the Academy which hopes to eliminate preventable blindness
from diabetes by the year 2000. |
