1. Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa, United States
2. The Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
3. Department of Molecular Physiology and Biophysics, The University of Iowa, Iowa City, Iowa, United States
4. Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
5. Geriatric Research Education and Clinical Center, Pittsburgh VA Healthcare System, Pittsburgh, Pennsylvania, United States
6. Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States