Over 20 million Americans have diabetes. It is the leading cause of blindness
in North Americans under 65 years of age. Diabetes is a condition where the
body either cannot produce enough insulin (type 1 diabetes) or cannot respond
properly to insulin (type 2 diabetes). Insulin is important because it
moves glucose, a simple sugar, into the body's cells from the blood.
Glucose, which is used by the cells as a source of energy, comes from the food
people eat. If insulin isn't available or doesn't work correctly to move glucose
from the blood into cells, glucose will stay in the blood, leading to high blood
sugar levels.
High blood sugar levels damage the blood vessels, including the tiny blood
vessels in the eye. This leads to an eye disease known as diabetic retinopathy.
The retina is an area at the back of the eye that changes light into nerve signals.
With diabetic retinopathy, some blood vessels in the retina are lost, and some
of the other blood vessels begin to "leak" blood. This causes the
retina to swell, and gradually cuts off its supply of oxygen and nutrients.
Eventually, the retina starts to grow new blood vessels to replace the damaged
ones. Unfortunately, these new vessels are not as strong as the old ones and
are more likely to break, causing bleeding in the eye.
At first, people with diabetic retinopathy will not notice any symptoms. As
the disease gets worse, they may notice blurred vision, black spots or flashing
lights. Eventually, it can progress to blindness. Everyone with diabetes is
at risk for diabetic retinopathy, and the risk increases the longer you've had
diabetes.
Fortunately, you can reduce your risk. If you do not have diabetes, but think
you may be at risk for this condition, visit your doctor to be screened for
diabetes. If you do have diabetes:
- Have frequent eye check-ups:
- People with type 1 diabetes should have an eye check-up every year,
starting 5 years after they are diagnosed with diabetes.
- People with type 2 diabetes should have an eye check-up every year,
starting as soon as they are diagnosed.
- Pregnant women with diabetes are especially at risk. They should have
an eye check-up every trimester.
- Make sure you monitor your blood sugar frequently and use your medications
as recommended by your doctor. There is evidence that keeping your blood sugar
under tight control can slow down eye damage.
- If you have high blood pressure, follow your recommended diet and medications
to keep it under control. If you are not sure whether you have high blood
pressure, or whether your blood pressure is under control, discuss this with
your doctor.
- If you begin to develop diabetic retinopathy, there are treatments that
can slow down the damage, although they do not cure the condition. Laser surgery
is used to seal "leaky" blood vessels in the eye and prevent new
ones from forming. Vitrectomy is used for people who have a lot of
bleeding in the eye. The cloudy eye fluid is replaced by a salt solution to
improve the sight.