1. Department of Ophthalmology, University Hospital Düsseldorf, Düsseldorf, Germany
2. Institut für Refraktive and Ophthalmo-Chirurgie (IROC), Zürich, Switzerland
3. Department of Ophthalmology, Kepler University Hospital, Linz, Austria
4. Medical Faculty, Johannes Kepler University Linz, Linz, Austria
5. Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland