1. Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing OX3 9DU, United Kingdom
2. Oxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West Wing OX3 9DU, United Kingdom
3. Department of Ophthalmology, University of Bonn, 53127 Bonn, Germany
4. Clinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SO16 6YD Southampton, United Kingdom
5. University Hospital Southampton NHS Foundation Trust, SO16 6YD Southampton, United Kingdom