VISUS, University of Stuttgart, Allmandring 19, Stuttgart, Germany. corinna.vehlow@visus.uni-stuttgart.de.|School of Medicine, University of Colorado, E 17th Pl, Aurora, CO, USA. david.kao@ucdenver.edu.|School of Medicine, University of Colorado, E 17th Pl, Aurora, CO, USA. michael.bristow@ucdenver.edu.|School of Medicine, University of Colorado, E 17th Pl, Aurora, CO, USA. larry.hunter@ucdenver.edu.|VISUS, University of Stuttgart, Allmandring 19, Stuttgart, Germany. daniel.weiskopf@visus.uni-stuttgart.de.|School of Medicine, University of Colorado, E 17th Pl, Aurora, CO, USA. carsten.goerg@ucdenver.edu.