1. Athens Vision Eye Institute, Kallithea, 17673 Athens, Greece
2. First Department of Ophthalmology, G. Gennimatas Hospital National and Kapodistrian University of Athens, 11527 Athens, Greece
3. First Department of Ophthalmology, AHEPA Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece
4. Moorfields Eye Hospital, London EC1V 2PD, UK
5. UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
6. Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA