1. Department of Ophthalmology, University of North Carolina, Chapel Hill, North Carolina;
2. Department of Epidemiology and Biostatistics, Norman J. Arnold School of Public Health, University of South Carolina, Columbia, South Carolina;
3. Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan;
4. Wilmer Eye Institute, Johns Hopkins University Hospital, Baltimore, Maryland;
5. Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina.