Relationship of glycemic control and diabetes duration to diabetic retinopathy. The progression of retinopathy in individuals in the Diabetes Control and Complications Trial is graphed as a function of the length of follow-up with different curves for different A1C values. (Adapted from The Diabetes Control and Complications Trial Research Group: Diabetes 44:968, 1995.) Source: Section 1. Endocrinology, Harrison's Principles of Internal Medicine, 18e Citation: Longo DL, Fauci AS, Kasper DL, Hauser SL, Jameson J, Loscalzo J. Harrison's Principles of Internal Medicine, 18e; 2012 Available at: http://accesspharmacy.mhmedical.com/DownloadImage.aspx?image=/data/books/harr/harr_c344f008.gif&sec=40760742&BookID=331&ChapterSecID=40727142&imagename= Accessed: December 15, 2017 Copyright © 2017 McGraw-Hill Education. All rights reserved