Birmingham Neuro-Ophthalmology (SPM), Queen Elizabeth Hospital, Birmingham, United Kingdom; Cancer Research UK Clinical Trials Unit (CRCTU) (VH, SG, KB), University of Birmingham, Birmingham, United Kingdom; Metabolic Neurology (AJS), Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom; Centre for Endocrinology (AJS), Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom; and Department of Neurology (AJS), Queen Elizabeth Hospital, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom.

Address correspondence to Alex J. Sinclair, PhD, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom; E-mail: [email protected].

A. J. Sinclair is funded by a Sir Jules Thorn Award for Biomedical Science. The view expressed is those of the authors and not necessarily those of the UK National Health Service.

S. P. Mollan reports other from Invex Therapeutics, other from Heidelberg engineering, other from Chugai-Roche Ltd, other from Janssen, other from Santhera, other from Allergan, other from Santen, other from Roche, and other from Neurodiem, outside the submitted work. K. Brock reports other from Invex Therapeutics; other from AstraZeneca, other from GlaxoSmithKline, other from Eli Lilly, and other from Merck, outside the submitted work. Professor Sinclair reports other from Novartis; other from Allergan, and personal fees from Invex therapeutics as well as share option and shareholdings. All other authors declare no competing interests.

S. P. Mollan and V. Homer joint first.