1. Ophthalmology Clinic, University Hospital of Larissa, University of Thessaly, 41110 Larissa, Greece
2. 2nd Ophthalmology Clinic, Aristotle University of Thessaloniki, 56403 Thessaloniki, Greece
3. Ophthalmology Clinic, University Hospital of Ioannina, University of Ioannina, 45500 Ioannina, Greece