1. Worker's Health Department; Universidade Federal de São Paulo; São Paulo Brazil
2. Department of Ophthalmology and Visual Science; Escola Paulista de Medicina, Universidade Federal de São Paulo; São Paulo Brazil
3. School of Medicine; University of Liverpool; Liverpool UK
4. Bradford Teaching Hospitals NHS Trust; Bradford UK
5. Cochrane Eyes and Vision; Queen's University Belfast; Belfast UK
6. Cochrane Eyes and Vision, ICEH; London School of Hygiene & Tropical Medicine; London UK