1. Department of Medical Biometry, Informatics and Epidemiology, Faculty of Medicine, University of Bonn, Sigmund-Freud-Str. 25, Bonn, Germany
2. University Eye Hospital Bonn, Sigmund-Freud-Strasse 25, Bonn, Germany
3. Institute of Statistics, Ulm University, Helmholtzstrasse 20, Ulm, Germany