1. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
2. Departments of Neurology and Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
3. Department of Biostatistics, University of Alabama at Birmingham, Birmingham, AL, USA
4. Departments of Neurology and Ophthalmology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
5. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA,