1. Oxford Eye Hospital; Oxford UK
2. London School of Hygiene & Tropical Medicine; Cochrane Eyes and Vision, ICEH; Keppel Street London UK WC1E 7HT
3. University of Oxford; Pain Research and Nuffield Department of Clinical Neurosciences; Pain Research Unit Churchill Hospital Oxford UK OX3 7LE
4. Moorfields Eye Hospital NHS Foundation Trust; 162 City Road London UK EC1V 2PD
5. Royal Berkshire Hospital NHS Trust; London Road Reading Berkshire UK RG1 5AN