1. Institute of Clinical Medicine, Faculty of Medicine University of Oslo Oslo Norway
2. Department of Ophthalmology Stavanger University Hospital Stavanger Norway
3. Department of Quality and Health Technology University of Stavanger Stavanger Norway
4. Department of Mathematics and Physics University of Stavanger Stavanger Norway
5. Department of Research Stavanger University Hospital Stavanger Norway
6. Department of Clinical Medicine, Section of Ophthalmology University of Bergen Bergen Norway
7. Department of Ophthalmology Haukeland University Hospital Bergen Norway
8. Department of Clinical Medicine, Faculty of Medicine University of Bergen Bergen Norway