1. Division of Epidemiology and Clinical Applications, Clinical Trials Branch, National Eye Institute/National Institutes of Health, Bethesda, Maryland
2. The EMMES Corporation, Rockville, Maryland
3. Neuroepidemiology Section, National Institute on Aging/National Institutes of Health, Bethesda, Maryland
4. Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts5Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts
5. Moran Eye Center, University of Utah, Salt Lake City