1. From the Schepens Eye Research Institute and2Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts; and the
2. Retinal Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts.
3. From the Schepens Eye Research Institute and4Program in Neuroscience,2Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts; and the