1. Department of Ophthalmology, Molecular Ophthalmology Group, University Hospital Essen , 45147 Essen , Germany
2. Department of Otorhinolaryngology, University Hospital Essen , 45147 Essen , Germany
3. Department of Cardiology and Vascular Medicine, West German Heart and Vascular Center, University Hospital Essen , 45147 Essen , Germany
4. Institute of Physiology, University Hospital Essen , 45147 Essen , Germany