1. The Department of Ophthalmology, California Pacific Medical Center, San Francisco, California, USA
2. The Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA
3. The Francis I. Proctor Foundation, UCSF School of Medicine, San Francisco, California, USA
4. The Department of Ophthalmology, Hospital Clinic of Barcelona, Barcelona, Spain
5. Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany