1. Scottish National Blood Transfusion Service, Edinburgh, United Kingdom
2. Royal Liverpool and Broadgreen University Hospitals St. Paul’s Eye Unit, Liverpool, United Kingdom
3. Princess Alexandra Eye Pavillion, Edinburgh, United Kingdom
4. Tennent Institute of Opthalmology, Gartnavel General Hospital, Glasgow, United Kingdom
5. Institute of Infection, Immunity, and Inflammation University of Glasgow, Glasgow, United Kingdom