1. From the Aravind Eye Hospital Pondicherry, Pondicherry, India;
2. the Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India;
3. Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom;
4. Lions Aravind Institute of Community Ophthalmology, Aravind Eye Care, Madurai, India;
5. Dipartimento di Scienze Otorino-Odonto-Oftalmologiche e Cervico Facciali, Sezione di Oftalmologia, Universita'degli Studi di Parma, Parma, Italy; and
6. Ophthalmology and Vision Science, Queen's University Belfast, United Kingdom.