1. Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
2. Duke Eye Center, Duke University Medical Center, Durham, North Carolina
3. Barnes Retina Institute, St Louis, Missouri
4. Casey Eye Institute, Oregon Health and Science University, Portland
5. Retina-Vitreous Associates Medical Group, Beverly Hills, California
6. Wills Eye Retina Service, Wills Eye Hospital, Philadelphia, Pennsylvania
7. Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio