*Birmingham and Midland Eye Centre, Birmingham
**Department of Epidemiology, Institute of Ophthalmology
††Glaucoma research unit, Moorfields Eye Hospital, London, UK
†National University Hospital
‡Singapore National Eye Centre
∥National University of Singapore, Singapore
§Wilmer Eye Institute and Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
¶Cole Eye Institute, Cleveland, OH
♯Doheny Eye Institute, University of Southern California Keck School of Medicine, Los Angeles, CA
Financial support: National University of Singapore: Grant nos. R-191000007101 and R-191000007112.
Reprints: Dr Winifred P. Nolan, MD, FRCOphth, Birmingham and Midland Eye Centre, Dudley Road, Birmingham B18 7QU, UK (e-mail: [email protected]).
Received for publication December 29, 2006; accepted December 7, 2007