original_query: What is diabetic retinopathy?
query: What is diabetic retinopathy?
answer: Diabetic retinopathy, also known as diabetic eye disease (DED), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries.  It affects up to 80 percent of those who have had diabetes for 20 years or more.