Waiting for a Diabetes Cure Part 2: Treating the Complications

posted 11/01/02

BOSTON, Mass.  --  More than 17 million Americans are living with diabetes. Nerve damage from diabetes is a leading cause of amputations in the United States. Diabetes is also the leading cause of blindness in working age adults. Now, new treatments may change the outlook for many patients.

Blindness, kidney disease, nerve damage, amputations, heart disease, stroke -- Everyday fears for people with diabetes.

Iris Larson has lived with the fear, and the reality, for 54 years. She tells Ivanhoe, "I have very little vision in my right eye. I have good vision in my left eye, good enough so I can drive."

Ophthalmologist Lloyd Aiello, M.D., Ph.D., says nearly every patient with diabetes will eventually develop eye damage.

"The two main problems that result in vision loss are either leakage of vessels when they're not supposed to be leaking. Or when vessels grow where they're not supposed to," says Dr. Aiello, of Joslin Diabetes Center in Boston.

Laser therapy is the standard treatment for advanced disease.

Dr. Aiello says, "The laser actually functions by being a destructive treatment. It actually destroys areas of the retina in an attempt to save more vision that would happen otherwise." But it has to be done soon enough and there are side effects, including impaired night vision and peripheral vision loss.

A new treatment under study goes to the source of the problem, which is a protein called VEG-F.

"VEG-F is a protein whose primary actions are to cause blood vessels to grow or blood vessels to leak," says Dr. Aiello.

A drug, eye-001, prevents VEG-F from working.

Dr. Aiello says, "This can theoretically give us a way that these patients cannot only prevent the complications in the future or reduce them, but do so in a way with fewer side effects."

Another new drug, a PKC inhibitor, targets nerve damage, or neuropathy.

Aaron Vinik, M.D., of Eastern Virginia Medical School, tells Ivanhoe, "There are 85,000 amputations every year in the United States. Eighty-seven percent of the precipitating factor there is that of neuropathy."

Most drugs simply help symptoms. PKC inhibitors do more.

"This compound improves the blood supply to the nerves so it addresses the basic biology of nerve damage," says Dr. Vinik.

He says the drug also improves reflexes, sensory levels and other measures of nerve damage. "It not only slowed the progression, but it showed that you could actually get some reversal of the nerve damage."

That's important for patients like Greg Stone. He was diagnosed with diabetes in 1990 and has neuropathy. He says, "I started losing feeling in my toes. It has moved progressively into both feet, up to the ankles and calves in both legs."

Stone is banking on new drugs. "One of these days, there's hope that someday again I can regain the feeling that I've already lost," he says.

PKC inhibitors may also improve vision problems and help patients like Larson. But she wants more than help. "I would like to see a cure. The other thing I would like to do is dance at my grandkids wedding," she says.

In early studies, Dr. Vinik says PKC inhibitors are also improving additional diabetes complications like kidney disease and heart disease. For a checklist of skills to better manage diabetes, which can help prevent future complications, click here.