1. From the Departments of Community, Occupational and Family Medicine and3Ophthalmology, National University of Singapore, Singapore; the2Singapore Eye Research Institute, Singapore; the
2. Division of Clinical Trials and Epidemiological Sciences, National Cancer Centre, Singapore; the
3. Department of Child and Adolescent Psychiatry, Institute of Mental Health, Singapore; and the
4. From the Departments of Community, Occupational and Family Medicine and
5. Ophthalmology, National University of Singapore, Singapore; the2Singapore Eye Research Institute, Singapore; the
6. Department of Ophthalmology, University of Pennsylvania School of Medicine, Scheie Eye Institute, Philadelphia, Pennsylvania.