1. F. I. Proctor Foundation, University of California, San Francisco, San Francisco, CA, USA
2. Aravind Eye Care System, Madurai, India
3. Aravind Eye Care System, Coimbatore, India
4. Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
5. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
6. Institute for Global Health, University of California, San Francisco, San Francisco, CA, USA