1Department of Ophthalmology and Visual Sciences, The University of Iowa Center for Macular Degeneration, PFP 11190E, 200 Hawkins Drive, The University of Iowa, Iowa City, IA 52240, USA
2The Institute of Ophthalmology, University College of London, Moorfields Eye Hospital, London, UK
3Center for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, CA, USA