New Therapies Slow Vision Loss in Diabetics

New Therapies Slow Vision Loss in Diabetics

Researchers have found two new treatments that could slow the progression of vision loss in high-risk adults with type 2 diabetes. The vision loss, called diabetic retinopathy, is caused by damage to the blood vessels in the retina. In diabetics with retinopathy, the blood vessels can leak and causing the retina to swell. Abnormal new blood vessels can also develop which causes vision loss.

In the largest study of its kind to date, trial investigators followed 2,865 type 2 diabetics. Just under 50 percent of patients had mild retinopathy at the start of the trial. Over a four-year period, researchers took retinal photographs that recorded any changes in the blood vessels and the progression of retinopathy.

"Many people with diabetes have microvascular problems, which can result in problems with the kidneys and amputation of toes and feet, and the only place that you can directly observe the microvasculature is in the back of the eyes," said Walter Ambrosius, Wake Forest University Baptist Medical Center, and principal investigator of the ACCORD Eye Study. "What we have seen in the eyes is potentially an indicator of what is happening in other parts of the body."

Patients in the study were given three types of treatments. Therapy to control and normalize their blood sugar, treatments to control blood pressure and bring it within normal levels and a combination of lipid and fenofibrate therapy. Fenofibrates are cholesterol-lowering drugs that lower triglycerides-fat stored in the body–and raise HDL levels, also known as good cholesterol.

They found both the intensive blood sugar control and the combination therapy decreased the progression of vision loss by one-third. The third treatment, statin therapy plus a placebo had no effect.

"Previous clinical trials have shown the beneficial effects of intensive blood sugar control on slowing the progression of diabetic retinopathy in people with type 1 diabetes or newly diagnosed type 2 diabetes," said Paul Sieving, director of the National Eye Institute at the National Institutes of Health. "The ACCORD Eye Study expands these findings to a larger population of adults who had type 2 diabetes for an average of 10 years, and demonstrates that the eye benefits from the reduction of glucose below previously established levels."

But researchers said there was one safety concern. Patients in the intensive blood sugar control arm of the study had a higher risk of severe low blood sugar and death. The National Eye Institute says doctors need to consider these risks when discussing a treatment plan with their patients.