1. Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
2. Department of Ophthalmology, University of California, San Francisco, United States
3. Department of Ophthalmology, University of Miami Bascom Palmer Eye Institute, Miami, FL, United States
4. Department of Ophthalmology, Corporal Michael J. Crescenz Veterans Affairs Medical Center, Philadelphia, PA, United States