Academic Unit of Ophthalmology, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK. Academic Unit of Ophthalmology, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK; Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Health Data Research UK, London, UK; Centre for Regulatory Science and Innovation, Birmingham Health Partners, Birmingham, UK. Department of Ophthalmology and Visual Sciences, McGill University, Montreal, QC, Canada. Moorfields Eye Hospital NHS Foundation Trust, London, UK; Stanford University Byers Eye Institute, Palo Alto, CA, USA. Moorfields Eye Hospital NHS Foundation Trust, London, UK; Eye Clinic, Cantonal Hospital of Lucerne, Lucerne, Switzerland. National Institute for Health Research Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK. Health Data Research UK, London, UK. International Centre for Eye Health, Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, UK. Academic Unit of Ophthalmology, Institute of Inflammation & Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK; Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK; Health Data Research UK, London, UK; Centre for Regulatory Science and Innovation, Birmingham Health Partners, Birmingham, UK; National Institute for Health Research Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK. Electronic address: a.denniston@bham.ac.uk.