1. From the Departments of Community, Occupational and Family Medicine and4Ophthalmology, National University of Singapore, Singapore; the2Singapore Eye Research Institute, Singapore; the3Singapore National Eye Centre, Singapore; and
2. Singapore Eye Research Institute, Singapore; the3Singapore National Eye Centre, Singapore; and
3. From the Departments of Community, Occupational and Family Medicine and
4. Ophthalmology, National University of Singapore, Singapore; the2Singapore Eye Research Institute, Singapore; the3Singapore National Eye Centre, Singapore; and
5. The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.