Helen Z Y Wu1, Kate E Ahmad1, Kimberley Tan1, Nicholas F Blair2. 1. From the Department of Neurology (H.Z.Y.W., K.E.A., N.F.B.) and Department of Ophthalmology (K.T.), Royal North Shore Hospital, Sydney, Australia. 2. From the Department of Neurology (H.Z.Y.W., K.E.A., N.F.B.) and Department of Ophthalmology (K.T.), Royal North Shore Hospital, Sydney, Australia. nblair@med.usyd.edu.au.