1 Second Department of Ophthalmology, Medical School, National & Kapodistrian University of Athens, University General Hospital Attikon, Chaidari, Greece.
2 Department of Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
3 Graduate School of Medical Sciences (Research School of Behavioural and Cognitive Neurosciences), University of Groningen, Groningen, The Netherlands.