Dr. Weiye Li, Professor Emeritus, Retina Surgeon, and Researcher of Drexel University, College of Medicine, an internationally renowned expert in the study of diabetic retinopathy and age-related macular degeneration, shares his practice, experience, and insight in this book. Dr. Jingfa Zhang, Senior Scientist and Attending Physician at the Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, P.R. China, is a physician-scientist focusing on diabetic retinopathy and age-related macular degeneration.