Collom & Carney Eye Institute

Diabetic Retinopathy

Diabetic Retinopathy
 Diabetic retinopathy is the most common diabetic eye disease and one of the leading causes of blindness in American adults under the age of 65.  It is caused by changes in the blood vessels of the retina, usually the result of higher than normal blood sugar levels.  Over time, diabetes affects the circulatory system of the retina.  There are two different types of diabetic retinopathy, differing in their levels of severity and damage to the eye.

The most common form of the disease is background diabetic retinopathy (BDR), and is also known as nonproliferative diabetic retinopathy (NPDR).  In this phase, the arteries in the retina become weakened and leak, oozing fluid or blood into the retina forming small, dot like hemorrhages.  Some of the larger retinal veins and patches of nerve fibers can become swollen.  These are often called cotton-wool spots because their wispy, cottony appearance.  These leaking vessels often lead to swelling, or edema, in the retina and decreased vision.
The next stage is known as proliferative diabetic retinopathy.  At this advanced stage, the signals sent by the retina for nourishment trigger the growth of new blood vessels.  These new blood vessels are abnormal and are fragile.  They grow along the retina and along the surface of the clear, vitreous gel that fills the inside of the eye.  By themselves, these blood vessels do not cause symptoms of vision loss, however because they are so fragile, they can leak blood and severe vision loss can be a result.
    How do I know if I have diabetic retinopathy?
 A medical eye exam is the only way to find changes inside of your eye.  An Ophthalmologist can often diagnose and treat serious retinopathy before you are aware of any vision problems.  If you notice the sudden appearance of floaters, spider webs, spots in front of your eyes, or blurred vision you should promptly call your eye doctor.  The Ophthalmologists at Collom and Carney Eye Institute recommend that diabetics get a dilated eye exam at least once a year to make sure there have been no changes or damage to the vessels in the eye.  All people with diabetes--both type 1 and type 2--are at risk.  That's why everyone with diabetes should get a comprehensive dilated eye exam at least once a year.  The longer someone has diabetes, the more likely he or she will get diabetic retinopathy.  Between 40 to 45 percent of Americans diagnosed with diabetes have some stage of diabetic retinopathy.  If you have diabetic retinopathy, you doctor can recommend treatment to help prevent its progression.
     What other eye problems are associated with diabetes?
Cataracts - clouding of the eye's lens.  Cataracts develop at an earlier age in people with diabetes. Glaucoma - increase in fluid pressure inside the eye that leads to optic nerve damage and loss of vision.  A person with diabetes is nearly twice as likely to get glaucoma as other adults. Macular edema - swelling of thickening of the retina. Vitreous hemorrhage - bleeding from neovascularization into the vitreous cavity. Traction retinal detachment - scar tissue pulling the retina off of the back wall of the eye.
     How are diabetic retinopathy and macular edema detected?

Diabetic retinopathy and macular edema are detected during a comprehensive eye exam that includes:


    Visual acuity test.  This eye chart test measures how well you see at various distances. Dilated eye exam.  Drops are placed in your eyes to widen, or dilate, the pupils.  This allows the eye care professional to see more of the inside of your eyes to check for signs of the disease.  Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems.  After the exam, your close-up vision may remain blurred for several hours. Tonometry.  An instrument that measures the pressure inside the eye.  Numbing drops may be applied to your eye for this test.

Your eye care professional checks your retina for early signs of the disease, including:

Leaking blood vessels. Retinal swelling (macular edema). Pale, fatty deposits on the retina--signs of leaking blood vessels. Damage nerve tissue. Any changes to the blood vessels.

If your eye care professional believes you need treatment for macular edema, he or she may suggest a fluorescein angiogram .  In this test, a special dye is injected into your arm.  Pictures are taken as the dye passes through the blood vessels in your retina.  The test allows your eye care professional to identify leaking blood vessels and recommend treatment.

      What is Fluorescein Angiogram?
Fluirescien angiography is a test, which allows the blood vessels in the back of the eye to be photographed as a fluorescent dye is injected into the bloodstream via your hand or arm.  In just seconds, the dye travels to the blood vessels inside the eye.  A camera equipped with special filters that highlight the dye is used to photograph the fluorescein as it circulates through the blood vessels in the back of the eye.  If there are any circulation problems, swelling, leaking or abnormal blood vessels, the dye and its patterns will reveal these in the photographs.  The doctor can then make a determination as to the diagnosis, and possible treatment options for the patient.  It is particularly useful in the management of diabetic retinopathy and macular degeneration.  This test is done to help the doctor confirm a diagnosis, to provide a guideline for treatment, and to keep a permanent record of the vessels at the back of the eye.

At the time of the angiogram, your pupils will be dilated with eye drops and the yellow dye is injected into your bloodstream.  During the injection you may feel a warm feeling or a hot flush can be experienced.  This feeling only lasts seconds and then disappears.  After the injection, photos are quickly taken over a period of a few minutes, typically of both eyes.  The flash on the camera will appear very bright; however it will not damage your eyes.  It is common for your skin to appear a pale yellow color and your urine to be colored fluorescent yellow and this may take a few days to wear off.
     What treatments are offered for diabetic eye disease?

Diabetic retinopathy can be treated with laser photocoagulation to seal off leaking blood vessels and destroy new growth.  Laser photocoagulation doesn't cause pain, because the retina does not contain nerve endings.  In some patients, blood leaks into the vitreous humor and clouds vision.  The eye doctor may choose to simply wait to see if the clouding will dissipate on its own, a period called "watchful waiting."


A procedure called a vitrectomy removes blood that has leaked into the vitreous humor.  The body gradually replaces lost vitreous humor, and vision usually improves.  If diabetic retinopathy has caused your body to form a cataract, it can be corrected surgically.  Patients who have developed glaucoma should see a glaucoma specialist.

     I am a diabetic.  What can I do to prevent diabetic eye disease?

Fortunately, you can significantly reduce your risk of developing diabetic retinopathy by using common sense and taking good care of yourself.

Keep your blood sugar under good control. Monitor your blood pressure and keep it under good control, or seek appropriate care. Maintain a healthy diet. Exercise regularly. Follow your doctor's instructions to the letter
If you have diabetes and do not see an Ophthalmalogist at least once a year, please call Collom and Carney Eye Institute today to schedule an appointment.

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