1. Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
2. Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
3. Orbis International Ethiopia, Addis Ababa, Ethiopia
4. Sightsavers, Haywards Heath, UK
5. Kilimanjaro Centre for Community Ophthalmology, Division of Ophthalmology, University of Cape Town, Cape Town, South Africa
6. Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA