1 Birmingham Neuro-Ophthalmology, Queen Elizabeth Hospital, University Hospitals Birmingham, Birmingham, B15 2WB, UK. [email protected].
2 Luton and Dunstable University Hospital, Lewsey Road, Luton, LU4 0DZ, UK.
3 Metabolic Neurology, Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
4 The Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Roosevelt Drive, Headington, Oxford, OX3 7FY, UK.