|
Definition
Diabetes can affect sight by causing
cataracts, glaucoma, and most importantly, damage to blood vessels
inside the eye. Diabetic retinopathy is a complication of diabetes
that is caused by changes in the blood vessels of the retina. When
blood vessels in the retina are damaged, they may leak blood and grow
fragile, brush-like branches and scar tissue. This can blur or distort
the vision images that the retina sends to the brain.
Diabetic eye disease is a leading cause of severe visual loss in the
United States. People with untreated diabetes are said to be 25 times
more at risk for blindness than the general population. The longer a
person has had diabetes, the higher the risk of developing diabetic
retinopathy. People with juvenile diabetes are, therefore, at a higher
risk of developing diabetic retinopathy. Diabetic retinopathy causes
8,000 new cases of blindness in this country each year. But if a
person with diabetes receives proper eye care regularly, and treatment
when necessary, diabetic retinopathy will rarely cause total
blindness. If you have diabetes, your ophthalmologist can help to
prevent serious vision problems.
Proliferative Retinopathy describes the changes that occur when new,
abnormal blood vessels begin growing on the surface of the retina.
This abnormal growth is called neovascularization. If these abnormal
blood vessels grow around the pupil, glaucoma can result from the
increasing pressure within the eye. These new blood vessels have
weaker walls and may break and bleed, or cause scar tissue to grow
that can pull the retina away from the back of the eye. When the
retina is pulled away it is called a retinal detachment and if left
untreated, a retinal detachment can cause severe vision loss,
including blindness. Leaking blood can cloud the vitreous (the clear,
jelly-like substance that fills the back of the eye) and partially
block the light passing through the pupil to the retina, causing
blurred and distorted images. In more advanced proliferative
retinopathy, diabetic fibrous or scar tissue can form on the retina.
Proliferative retinopathy typically develops in Type I diabetes
(juvenile onset diabetes).
Nonproliferative Retinopathy describes the condition where retinal
blood vessels can develop tiny leaks. When this occurs, blood and
fluid seep from the retinal blood vessels, and fatty material (called
exudate) deposits in the retina. This causes swelling of the retina
and is called nonproliferative diabetic retinopathy. When this occurs
in the central part of the retina (the macula), vision will be reduced
or blurred. Leakage elsewhere in the retina will usually have no
effect on vision. Nonproliferative retinopathy is more common in Type
II diabetes (so-called maturity onset diabetes).
Symptoms
Difficulty reading
Blurred vision
Sudden loss of vision in one eye
Seeing rings around lights
Dark spots or flashing lights
NOTE: Pregnancy and high blood pressure may aggravate diabetic
retinopathy.
The symptoms described above may not necessarily mean that you have
diabetic retinopathy. However, if you experience one or more of these
symptoms, contact your eye doctor for a complete exam.
Treatments
In many cases treatment for diabetic retinopathy is not necessary, but
you will need to continue having regular eye exams. For example,
strict control of blood sugar levels can reduce or prevent diabetic
retinopathy.
In other cases, treatment is recommended to stop the damage of
diabetic retinopathy and improve sight. The ophthalmologist will
consider your age, medical history, lifestyle, and the amount of
retinal damage before making a decision to treat or not.
Laser surgery is often helpful in treating diabetic retinopathy. A
powerful beam of laser light is focused on the damaged retina and many
small bursts of the laser's beam are used to seal leaking retinal
vessels to reduce macular edema. This is called photocoagulation. For
abnormal blood vessel growth (neovascularization), the laser beam
bursts are focused in an area or scattered over the retina. The small
laser scars that result will reduce abnormal blood vessel growth and
help bond the retina to the back of the eye, thus preventing retinal
detachment. Laser surgery may be performed in your ophthalmologist's
office or in an out-patient clinic. If diabetic retinopathy is
detected early, laser surgery will slow down loss of vision. Even in
the more advanced stages of this disease (proliferative retinopathy),
it can reduce the chance of severe visual impairment.
As with all surgical procedures, laser surgery carries risks
especially when treating near the centre point of vision. You should
discuss these with your doctor.
Cryotherapy (freezing) may be helpful in treating diabetic
retinopathy. If the vitreous is clouded by blood, laser surgery cannot
be used until the blood settles or clears. In some of these cases
retinal cryotherapy may help shrink the abnormal blood vessels and
bond the retina to the back of the eye.
Vitrectomy may be recommended in advanced proliferative diabetic
retinopathy. Vitrectomy removes the blood-filled vitreous and replaces
it with a clear solution. Your ophthalmologist may wait from several
months to a year to see if the blood will clear on its own, before
going ahead with a vitrectomy. This microsurgical procedure is
performed in the operating room.
Retinal repair may be necessary if scar tissue has detached the retina
from the back of the eye. Severe loss of vision or even blindness can
result if surgery is not performed to reattach the retina.
What Is Your Part In Treatment?
Successful care of diabetic retinopathy depends not only on early
treatment by your ophthalmologist, but especially on your attitude and
attention to medications and diet. You must maintain blood sugar
levels, avoid smoking and watch your blood pressure. Physical activity
usually poses no problem for people with background retinopathy.
Occasionally, people with active proliferative retinopathy are advised
to restrict their physical activity.
|
