1. From the Fundus Photograph Reading Center, Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin;
2. the Jaeb Center for Health Research, Inc., Tampa, Florida;
3. the Beetham Eye Institute and Eye Research Section, Joslin Diabetes Center, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts; and
4. the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland.