1. Retina Department, Asociación Para Evitar la Ceguera en México, “Hospital Dr. Luis Sanchez Bulnes”, IAP, Mexico City 04030, Mexico
2. Retina Department, Sanatorio del Salvador, Córdoba X5004, Argentina
3. Asociados de Macula, Vitreo y Retina de Costa Rica, San José 10102, Costa Rica
4. Department of Ophthalmology, Illinois Eye and Ear Infirmary, School of Medicine, University of Illinois, Chicago, IL 61801, USA