1 Division of Neuro-ophthalmology (LM, EF, BKC), Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, Massachusetts; Division of Neuro-ophthalmology (MAB), Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts; Department of Neurobiology (DHB, SRD), Harvard Medical School, Boston, Massachusetts; Division of Neuro-ophthalmology (SP), Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; and Department of Neurology (BKC), Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts.