1. From the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;2Medical Research Council Laboratories, Fajara, The Gambia; the
2. From the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;3National Eye Care Programme, The Gambia.;4CCBRT Disability Hospital, Dar Es Salaam, Tanzania; and the
3. National Eye Care Programme, The Gambia.;
4. Medical Research Council Laboratories, Fajara, The Gambia; the
5. From the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;
6. From the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;5Division of Epidemiology and International Eye Health, Institute of Ophthalmology, London, United Kingdom.