What is diabetes?
Diabetes is a disease
resulting from a variable interaction of hereditary and environmental
factors. It results in abnormal insulin secretion and elevated blood
glucose levels that cause a variety of organ complications including
kidney disease, eye disease, nerve disease, and blood vessel disease.
Symptoms of diabetes include excessive thirst, appetite, and
urination. Approximately 8 million people in the USA have
diabetes.
Diabetes falls into
three groups. Type 1, also called juvenile onset diabetes, typically
occurs between age 11 and 13. It is unusual for an individual to have
Type 1 after age 40. People with Type 1 require treatment with
insulin. Type 2 typically occurs in people over 40. Obesity is a
factor in 80%-90% of people with Type 2. Individuals with Type 2
diabetes are treated by diet modification, oral medication, and
sometimes insulin. The third group of diabetes occurs secondarily to
other conditions such as pancreatic disease, endocrine gland disease,
and certain drug induced forms.
How does diabetes affect the
eye?
Diabetes affects many
parts of the eye. Diabetes can cause physiologic alterations in the
human lens leading to fluctuations in vision and cataract formation.
It can also cause sudden onset of double vision and decreased corneal
sensitivity. Diabetes is a risk factor for glaucoma as well as
various vascular obstructions in the eyes. The most serious and
potentially blinding eye condition associated with diabetes is
diabetic retinopathy. The diagnosis of diabetic eye disease is made
by optometric physicians during a complete eye
examination.
What is retinopathy?
Persistently elevated
blood glucose levels in an individual causes damage to the tiny blood
vessels in the retina. Unhealthy vessels allow leakage of blood and
fluid into the retina, which can permanently damage retinal tissue.
The irreversible damage caused by diabetic retinopathy leads to
permanent vision loss. Failure to adequately control blood glucose
will promote the growth of new blood vessels in the retina and iris.
New blood vessels, called neovascularization, can cause severe
bleeding, scar tissue formation, and retinal detachment and glaucoma.
If diabetic retinopathy is untreated, blindness can
result.
Is vision loss from diabetes
preventable?
Yes. Early diagnosis
and aggressive treatment to control blood glucose levels are very
important in slowing the progression of diabetic retinopathy and
preventing vision loss. Yearly dilated eye examinations by an
optometric physician are necessary for all individuals with diabetes.
Although the damage from diabetic retinopathy is often irreversible,
medical and surgical intervention will stabilize the damaging effects
of diabetic retinopathy. Optometric physicians diagnose the presence
of diabetic retinopathy, evaluate the severity, and make direct
referrals to diabetologists and retinologists for laser treatment
when necessary.
What is the treatment for
diabetic retinopathy?
In early stages,
controlling blood glucose levels will slow the development of
retinopathy. As retinopathy progresses, blood and fluids leak out of
small blood vessels and accumulate in the central retina of the eyes.
Laser treatments to the areas of leakage help stop further leakage.
As retinopathy progresses, new blood vessels form inside the eye.
Extensive laser treatments and even surgery may be necessary to
prevent new blood vessel formation from causing blindness.
What are the risk factors for
developing retinopathy?
Several factors
increase the risk of developing retinopathy including high blood
pressure, carotid artery disease, and pregnancy. The prevalence of
retinopathy in the diabetic population increases with age. Diabetic
retinopathy rarely occurs in children under 10 years of age. However
after having diabetes for 20 years, nearly 99% of those with Type 1
diabetes and 60% of those with Type 2 have some degree of
retinopathy.
Is diabetic eye disease
preventable?
Early diagnosis and
treatment are essential in stabilizing diabetic eye disease. Regular
physical examinations and self discipline in following instructions
about diet, exercise and medication are of utmost importance.
Frequent dilated eye examinations by an optometric physician is
essential in preventing vision loss.