1. Department of Epidemiology University of Colorado, Anschutz Medical Campus Denver Colorado USA
2. Department of Ophthalmology University of Colorado, Anschutz Medical Campus Denver Colorado USA
3. Department of Epidemiology The Johns Hopkins Bloomberg School of Public Health Baltimore Maryland USA
4. Wilmer Eye Institute Johns Hopkins University School of Medicine Baltimore Maryland USA
5. Casey Eye Institute Oregon Health & Science University Portland Oregon USA
6. The MIND Center University of Mississippi Medical Center Jackson Mississippi USA