1. From Moorfields Eye Hospital, London, United Kingdom; the
2. From Moorfields Eye Hospital, London, United Kingdom; the2Division of Epidemiology, Institute of Ophthalmology, London, United Kingdom; the
3. Department of Ophthalmology, National Medical University of Mongolia, Ulaanbaatar, Mongolia; the
4. Division of Epidemiology, Institute of Ophthalmology, London, United Kingdom; the
5. Department of Ophthalmology, Hillerød Hospital, Hillerød, Denmark; and the
6. Division of Clinical Trials and Epidemiological Science, National Cancer Centre, Singapore.