1 Department of Optometry and Vision Science, City University London, United Kingdom;
2 Department of Optometry and Vision Science, City University London, United Kingdom; NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom;
3 Department of Ophthalmology, Queen Alexandra Hospital, Portsmouth, United Kingdom; and.
4 Gloucestershire Hospitals NHS Foundation Trust, Cheltenham, and Cranfield University, Bedford, United Kingdom.