Diabetic retinopathy, or eye disease, is a condition in which damaged blood vessels at the back of the eye leak fluids and abnormal new blood vessels develop, both potentially leading to vision loss. After having diabetes for 20 years, nearly everyone with Type 1 diabetes and more than 60% of people with Type 2 diabetes develop retinopathy. But results from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) Eye Study has shown that two treatments — intensive blood glucose control and the use of a combination of cholesterol-lowering statin and fibrate drugs — may be able to slow the progression of this condition.
The ACCORD study involved 10,251 adults with Type 2 diabetes who were at particularly high risk of cardiovascular conditions. A subset of ACCORD, the ACCORD Eye Study involved 2,856 of these participants and sought to determine whether intensive blood glucose control, intensive blood pressure control, or intensive blood lipid (fat) control could slow the progression of diabetic retinopathy. Intensive blood glucose control was achieved using a combination of glucose-lowering medicines; people in the intensive control group had a median A1C level of 6.4%, compared to 7.5% in the standard control group. Intensive blood lipid control was attained by means of a combination of simvastatin (brand name Zocor) and fenofibrate (Tricor and others), compared to just a statin drug in the standard control group. Intensive blood pressure control was accomplished with the use of various blood-pressure-lowering medicines.
Evaluating the participants at 4 years after the start of the study, the researchers discovered that both the intensive blood glucose control and the intensive lipid control resulted in a roughly one-third reduction in the rate of progression of diabetic retinopathy. Intensive blood pressure control was not found to have any effect on the progression of the condition.
The researchers noted, however, that there were more deaths in the intensive-blood-glucose-lowering group of the ACCORD study. The arm of the trial using this treatment strategy was stopped 18 months early in 2008 as a result, and researchers have offered a few different explanations for why there were more deaths in this group.
According to study chairwoman Emily Chew, MD, “The ACCORD Eye Study clearly indicates that intensive glycemic control and fibrate treatment added to statin therapy separately reduce the progression of diabetic retinopathy. The main ACCORD findings showed that fibrate treatment added to statin therapy is safe for patients like those involved in the study.” However, she went on to note the increased risk of low blood glucose and the higher rate of death in the intensive-glucose-lowering arm of the study, suggesting that people with diabetes and their doctors “take these potential risks into account when implementing a diabetes plan.”
For more information, read the article “Eye Study Finds Two Therapies Slow Diabetic Eye Disease” or see the study in The New England Journal of Medicine. And to learn more about keeping your eyes healthy, click here.