1. Centre de Recherche en Santé de Nouna, Nouna, Burkina Faso;
2. Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts;
3. Africa Health Research Institute, Somkhele, South Africa;
4. Heidelberg Institute of Global Health, Medical Faculty and University Hospital, University of Heidelberg, Heidelberg, Germany;
5. Francis I. Proctor Foundation, University of California, San Francisco, San Francisco, California;
6. Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, California;
7. Department of Ophthalmology, University of California, San Francisco, San Francisco, California