Joslin Researchers Discover Protein that Causes Blood Vessel Leakage in Eyes with Diabetic Retinopathy: BOSTON ??? January 29, 2007 ??? Although health professionals have had success in treating diabetic retinopathy, two forms of the disease ??? proliferative diabetic retinopathy and diabetic macular edema ??? still are the leading causes of vision loss and blindness among working age adults in th