1 Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK; Birmingham and Midland Eye Centre and Academic Unit of Ophthalmology, University of Birmingham, Birmingham, UK; Manchester Manchester Royal Eye Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK. Electronic address: george.moussa@nhs.net.
2 Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK.
3 Manchester Manchester Royal Eye Hospital, Manchester University Hospitals NHS Foundation Trust, Manchester, UK.
4 University Hospital Coventry and Warwickshire, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK.
5 Birmingham and Midland Eye Centre, Sandwell and West Birmingham Hospitals NHS Trust, Birmingham, UK; Kantonsspital Winterthur, Winterthur, Switzerland; University of Zurich, Zurich, Switzerland.