1. From the Princess Alexandra Eye Pavilion, Edinburgh, Scotland, United Kingdom; the 2Department of Public Health Sciences, University of Edinburgh, Scotland, United Kingdom;
2. Moorfields Eye Hospital, London, United Kingdom;
3. Gartnavel General Hospital, Glasgow, Scotland, United Kingdom; and
4. the Department of Public Health Sciences, University of Edinburgh, Scotland, United Kingdom;
5. the Aberdeen Royal Infirmary, Abderdeen, Scotland, United Kingdom.
6. From the Princess Alexandra Eye Pavilion, Edinburgh, Scotland, United Kingdom;