1. Department of Ophthalmology, University Hospital of Larissa, Larissa, Greece
2. Department of Medicine, University of Thessaly, Volos, Greece
3. Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
4. Department of Epidemiological Surveillance and Intervention for Infectious Diseases, National Public Health Organization of Greece, Athens, Greece
5. Department of Ophthalmology, Clinique de L'Oeil, Geneva, Switzerland
6. Infectious Disease Department, Geneva University Hospital, Geneva, Switzerland