1. Retina and Vitreous Service, Caracas Clinical Opthalmology Center, Caracas 1010, Venezuela
2. Retina and Vitreous Service, Instituto Nacional de Investigación en Oftalmologica (INIO), Medellín, Colombia
3. Retina and Vitreous Service, Instituto de Cirugia Ocular, San José, Costa Rica
4. Departamento de Oftalmologica, Instituto da Visão, Universidad Federal de São Paulo, 04021-001 São Paulo, SP, Brazil
5. Retina and Vitreous Service, Centro de Oftalmología Bonafonte, Barcelona, Spain
6. Retina and Vitreous Service, Instituto Docente de Especialidades Oftalmológicas (IDEO), Maracaibo, Venezuela
7. OFTALMOS, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
8. Department of Ophthalmology, University of Puerto Rico, San Juan, Puerto Rico
9. Department of Ophthalmology, Hospital Universitario Austral, Buenos Aires, Argentina
10. Hospital Dr. Luis Sanchez Bulnes, Asociación Para Evitar la Ceguera en Mexico 04030, Mexico City, Mexico