1. Wilmer Eye Institute, The Johns Hopkins University, Baltimore, Maryland
2. The University of Texas School of Public Health, Houston
3. Mayo Clinic, Rochester, Minnesota
4. Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, California
5. Department of Ophthalmology, Flinders University, Adelaide, South Australia
6. Wills Eye Hospital, Philadelphia, Pennsylvania
7. Bascom Palmer Eye Institute, Miami, Florida
8. Wilmer Eye Institute, The Johns Hopkins University, Baltimore, Maryland8Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland