1. Athens Vision Eye Institute, Cornea Service, Athens, Greece
2. Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
3. Jules Gonin Eye Hospital, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
4. Department of Ophthalmology, ‘Gennimatas Hospital’, National and Kapoditrian University of Athens, Athens, Greece