1 Division of Neurology, Department of Pediatrics, Neurosciences and Mental Health Program, SickKids Research Institute, Hospital for Sick Children, University of Toronto, Canada. Electronic address: ann.yeh@sickkids.ca.
2 Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
3 Department of Ophthalmology, Thomas Jefferson University Wills Eye Hospital, Philadelphia, Pennsylvania USA.
4 Department of Neurology, Massachusetts General Hospital and Harvard Medical School, USA.
5 Dept of Neurology, John Hunter Hospital, University Newcastle, Australia.