1. Charlie Norwood VA Medical Center, Augusta, Georgia,United States
2. Department of Physiology, Medical College of Georgia at Augusta University, Augusta, Georgia,United States
3. Department of Medicine, Medical College of Georgia at Augusta University, Augusta, Georgia,United States
4. Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia,United States
5. Hospital Internal Medicine, Mayo Clinic, Rochester, Minnesota, United States
6. Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, Georgia,United States