1. Programme FSS/Université Abdou Moumouni de Niamey, Programme Nationale des Soins Oculaire, Niamey, Niger
2. Francis I. Proctor Foundation, University of California, San Francisco, USA
3. Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, USA
4. Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
5. Department of Ophthalmology, University of California, San Francisco, USA
6. Department of Epidemiology & Biostatistics, University of California, San Francisco, USA