1. Retina, Asociados De Macula Vitreo Y Retina De Costa Rica, San Jose, Costa Rica
2. Centro Ocular, Heredia, Costa Rica
3. Cornea, Grupo Oftalmologico Abdala-Figuerola, Barranquilla, Colombia
4. Cuidad De Mexico, Insituto De Oftalmologia “Conde De Valenciana”, Mexico City, Mexico
5. Illinois Eye and Ear Infirmary, Dpt of Ophthalmology, University of Illinois School of Medicine, Chicago, Illinois, USA