Diabetes is a disease that affects the entire body--and that includes the eyes.
"Blurry vision, seeing spots or experiencing pressure or pain in the
eye are all symptoms of problems diabetics may be prone to," says
William David Boothe, MD, an ophthalmologist at
Covenant Health. "However, because these symptoms often don't appear until an
eye problem is in an advanced stage, it's important for people to
know what these diseases are and how to lower their risk."
Over time, high blood sugar wreaks havoc with the blood vessels in the
eyes. "Diabetic retinopathy moves through four stages as the blood
vessels swell and have trouble getting enough oxygen. New vessels will
start to grow in response, but those are weak and can burst or leak,"
Dr. Boothe says. "In the final stage, there is a great danger that
the retina--the tissues in the back of the eye--will detach and cause
profound vision loss." Diabetic retinopathy is the most common culprit
when it comes to diabetes-related vision loss. Once it's diagnosed,
it may be treated with laser therapy or medication. In severe cases, if
blood leaks into the eyes' vitreous gel, that substance may become
clouded and removed via a surgery called a vitrectomy.
Diabetic macular edema
Diabetic retinopathy can lead to this disease, which affects the macula,
an area in the retina that provides the eyes with the sharpness needed
to clearly see details. "Fluid leaking from the eyes' blood vessels
can cause the macula to swell, which can affect vision," Dr. Boothe
says. About half of the people with diabetic retinopathy will also get
diabetic macular edema, which is treated with drugs such as corticosteroids
or macular laser surgery.
While this is an eye problem that can affect anyone, diabetic adults are
up to five times as likely to get cataracts compared to people without
diabetes. Because the cataract clouds the lens of the eye, vision can
become blurry. "During the early stages, people with cataracts may
need to shield their eyes from bright light with sunglasses, or glasses
with a protective, anti-glare coating," Dr. Boothe says. "But
if the disease progresses, the lens of the eye may have to be removed
and replaced. However, lens removal can increase problems with retinopathy."
Diabetic adults have almost double the risk for glaucoma than non-diabetics.
That's because the diseases that fall under the glaucoma umbrella
are a result of increased pressure in the eye, which can be caused by
swollen or abnormal blood vessels affected by diabetic retinopathy. "Glaucoma
can impair the optic nerve, which runs from the eyes to the brain; that
can cause severe vision loss if not treated with eye drops, medication
or surgery," Dr. Boothe says.
What to do
For all of these eye diseases, the earlier the treatment, the better. To
lower the risk, or prevent vision loss, Dr. Boothe suggests:
An annual eye exam. "Everyone with diabetes needs to stay on top of their eye health
and get a thorough checkup at least once a year, or more frequently if
recommended by their physician," Dr. Boothe says. "The exam
should include a basic vision test with an eye chart, pupil dilation for
a more thorough examination of the eye for disease, and tonometry, which
tests the pressure in the eyes for glaucoma. A more advanced test is fluorescein
angiography, which uses dye to track blood flow in the retina. Spotting
a problem early, and getting it treated, can reduce vision loss."
Healthy blood pressure levels. "High blood pressure takes its toll on the body's blood vessels,
and those in the eyes are no different; it can lead to retinopathy,"
Dr. Boothe says. "Because people with diabetes have an increased
risk for high blood pressure, they should monitor it often, according
to doctor's instructions, and take any prescribed medication."
Meeting blood sugar targets. "The longer that blood sugar levels are high, the more likely they
will cause damage to the eyes," Dr. Boothe says. "It's important
to monitor blood sugar, and keep it under control with a healthy diet
and plenty of exercise."