1. Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom;
2. Department of Optometry and Visual Science, City University London, London, United Kingdom;
3. Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands; and 4Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands.