1. Ophthalmology, University General Hospital of Ioannina, Ioannina, Greece
2. Ophthalmology, University of Chicago, Pritzker School of Medicine, Chicago, Illinois, United States
3. Ophthalmology, Birmingham and Midland Eye Centre, Birmingham, United Kingdom of Great Britain and Northern Ireland
4. Ophthalmology, University of Ioannina Faculty of Medicine, Ioannina, Greece