A multicenter international study chaired by a Joslin Diabetes Center investigator and reported in the July issue of the American Diabetes Association’s journal Diabetes brings hopeful news to the 18 million people in the United States — and millions more worldwide — with type 1 or type 2 diabetes. Initial results of the Phase III clinical trial demonstrated that 32 milligrams per day of ruboxistaurin (RBX) was well tolerated and may reduce the risk of moderate vision loss, especially in patients with diabetic macular edema.Loss of vision is a common complication of diabetes and results from two primary conditions: diabetic retinopathy and diabetic macular edema. In diabetic retinopathy, tiny blood vessels in the retina become damaged. While early in the disease (the nonproliferative stage) there are often no symptoms, over time new, abnormal blood vessels proliferate and bleed easily. If untreated, proliferative diabetic retinopathy can cause severe vision loss. In diabetic macular edema, leaky blood vessels cause swelling in the macula — the part of the retina responsible for sharp central vision. Current laser treatments for diabetic eye diseases may help prevent severe vision loss, but because the laser destroys areas of the retina, side effects of treatment may include reduction in peripheral vision or night vision.
