Diabetic Retinopathy is a complication of diabetes and a disorder of the light sensitive tissue of the eye (the retina). This condition is characterized by destructive changes in the blood vessels of the retina, which, if left unchecked, may lead to visual impairment or blindness. The severity of the damage to the retina is highly correlated with the length of time the patient has had diabetes.
For reasons that are not well understood, the blood vessels of the retina lack their normal oxygen load. Capillaries tend to close off, further depleting the oxygen supply. The diabetes process also weakens the walls of these blood vessels, which tend to become enlarged and form micro-aneurysms. Not infrequently, the small blood vessels break causing hemorrhage and contributing to the patient's clouded vision.
The tiny blood vessels of the retina undergo pathologic changes. During the earliest stages of this form of retinopathy, no changes are visible to the ophthalmologist, but as the condition progresses venous dilation and small red dots may be seen by the ophthalmologist at the back of the retina.
Untreated, this condition can lead to vision impairment or blindness. (For more information, choose “Diabetes” as your search term in the Rare Disease Database.)
The earliest changes in the retina of diabetic people involve a reduction in blood flow and velocity. Later, in more advanced stages of Diabetic Retinopathy these changes can evolve into significantly increased blood flow along with development of physical abnormalities within the small vessel network of the retina.
Approximately 40% of all people with diabetes show at least mild signs of Diabetic Retinopathy. About 3% of patients with diabetes have suffered severe visual loss and blindness because of this disorder.
The goal of therapy is to maintain normal blood glucose levels. In some cases, this can help reverse changes in the small blood vessels of the eye. It is vital that people with diabetes have regular medical and ophthalmologic checkups to avoid onset of Diabetic Retinopathy. If normal glucose levels can be sustained, this complication of diabetes may be avoided.
In many cases, laser treatment can reduce the risk of vision loss from Diabetic Retinopathy. During such treatment, called photocoagulation, powerful laser light is aimed at several separate spots on the diseased retina. In most cases, this treatment can interrupt the disease process and prevent the development of additional retinal abnormalities. However, some patients may experience unwanted side effects, such as decreased central and side vision.
The blood and scar tissue caused by intensive bleeding inside the eye can now be removed by an experimental surgical technique known as vitrectomy. In some cases, vision may improve enough for patients to move around unaided and, occasionally, to resume reading or driving. However, more research is needed to determine the long-term safety and efficacy of this procedure.
Clinical studies using a new drug, sorbinil, are underway to determine whether the drug can prevent eye and nerve damage in diabetics who do not yet show signs of retinopathy.
Clinical trials are in progress to study suppression of Growth Hormone and Insulin-like Growth Factor 1 (IGF1) with Octreotide for prevention of progression of Diabetic Retinopathy. The results of the first set of these studies will be published shortly. Novartis, the pharmaceutical company that manufactures this therapeutic agent, plans a second clinical trial under the guidance of Dr. Maria Grant. Interested persons may wish to contact:
Maria Grant, M.D.
J-226 Shands Teaching Hospital
Jay Hillis Miller Health Center
University of Florida
Gainsvile, FL 32601
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
For information about clinical trials sponsored by private sources, contact:
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