1. University Hospitals Case Medical Center, Cleveland, Ohio
2. Biostatistics Center, George Washington University, Rockville, Maryland
3. Beetham Eye Institute, Joslin Diabetes Center, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
4. University of New Mexico, Albuquerque
5. Yale University School of Medicine, New Haven, Connecticut
6. Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison