As part of NAVH's Educational Series we are pleased to provide this excerpt from our article on DIABETIC RETINOPATHY by Stephen G. Shwartz, M.D.
Diabetes is the leading cause of new cases of legal blindness in the United States among working-age adults. In fact, vision loss is 25 times more common in persons with diabetes than in those without diabetes. What's more, the longer a person has had diabetes, the greater the risk of vision loss. As unfortunate as this is, this type of blindness is often preventable. This article is an attempt to help you understand the connection between diabetes and diabetic retinopathy. It will also explain tests and treatments for this condition.
WHAT IS RETINOPATHY, ANYWAY?
Retinopathy literally means "damage to the retina." There are actually two types of retinopathy that can occur if you have diabetes.
The most common type is early or background diabetic retinopathy. In this condition, diabetes has damaged the capillaries of the retina, and microscopic leaks have formed in these vessels. Leakage causes the retina to swell which interferes with normal vision. Background diabetic retinopathy may be associated with macula edema. The macula is the part of the retina affected; edema refers to the swelling caused by leakage. The macula, which enables us to see sharp detail, is the center of the retina, so macular edema can cause problems with central vision.
The second type of retinopathy is proliferative diabetic retinopathy. In this condition the capillaries of the retina shut down. This causes new blood vessels to grow in the retina (neovascularization). These new vessels are very delicate and can rupture and bleed easily. When they do, they bleed into the vitreous gel, the clear substance that fills the hollow part of the eye. This clouds vision and makes objects seem blurry.
Retinal neovascularization may also lead to scar tissue. This scar tissue may contract, pull on the retinal surface, and result in a retinal detachment. New blood vessels may grow on the iris of the eye and cause a form of glaucoma. These complications can cause a serious loss of vision, or even total blindness.
HOW DO I KNOW IF I HAVE RETINOPATHY?
Regular eye examinations by an ophthalmologist* with dilation of the pupil is the only certain way to know if you have retinopathy. If you have diabetes, early diagnosis of retinopathy is also the best way to insure effective treatment for you and to lessen the possibility of losing your vision. But even if the diagnosis is made late and diabetic retinopathy is advanced, effective treatment is often still possible.
After your retina is examined, further testing may be necessary to allow your doctor to develop a plan of treatment for you. One such test is called fluorescein angiography. Fluorescein angiography is a diagnostic test to examine the condition of the blood vessels of your retina. In this procedure, a small amount of a special dye called fluorescein is injected into a vein in your arm. Once in your blood, the dye is circulated to your eyes, where it highlights your retina's blood vessels and makes them easier to see. Photographs are taken of your retinas, and the specialist will examine these pictures. There are no X-rays or radiation used in this test.
THIS IS AN EXCERPT!
NAVH's members can order the complete article on DIABETIC RETINOPATHY by sending $1.50 to NAVH. The cost for nonmembers is $2.50. Contact NAVH.
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This excerpt is made possible through the cooperation of the following members of the National Association for Visually Handicapped's Medical and Technical Advisory Boards. Our special thanks and appreciation go to: Stanley Chang, M.D. James McGroarty, M.D. Vincent J. Mattaliano, Jr. Kenneth G. Noble, M.D. Jeanne Rosenthal, M.D. Joseph B. Walsh, M.D.
Copyright ©1992 by NAVH. All Rights Reserved. 1st Printing 1992, Revised 2004.