1. Department of Ophthalmology and Visual Sciences, W. K. Kellogg Eye Center University of Michigan, Ann Arbor, MI
2. Department of Ophthalmology, Columbia University Vagelos College of Physicians and Surgeons, Edward S. Harkness Eye Institute, New York, NY
3. Department of Ophthalmology and Visual Sciences University of Alabama at Birmingham, Birmingham, AL
4. Public Health Practice, Westat, Inc., Rockville, MD