*Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland; †Jaeb Center for Health Research, Tampa, Florida; ‡Department of Ophthalmology, Beetham Eye Institute, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts; §Division of Epidemiology and Clinical Applications, National Eye Institute and the National Institutes of Health, Bethesda, Maryland; and ¶Department of Ophthalmology, Wake Forest University Eye Center, Winston-Salem, North Carolina.