1. University Hospital Zurich, Department of Ophthalmology, Zurich, Switzerland (Chairman: K. Landau)
2. Cantonal Hospital Lucerne, Department of Ophthalmology, Lucerne, Switzerland (Chairman: M. Thiel)
3. Cantonal Hospital Winterthur, Department of Ophthalmology, Winterthur, Switzerland (Chairman: J. Stürmer)
4. Triemli Hospital Zurich, Department of Ophthalmology, Zurich, Switzerland (Chairman: M. Becker)