1. From the Department of Community Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India; the
2. Dipartimento di Scienze Otorino-Odonto-Oftalmologiche e Cervico Facciali, Sezione di Oftalmologia, Universita` degli Studi di Parma, Italy; the
3. Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, United Kingdom; and the
4. Department of Ophthalmology and Vision Science, The Queen’s University of Belfast, Northern Ireland, United Kingdom.