1. Department of Medical Biochemistry Oslo University Hospital Oslo Norway
2. Faculty of Medicine Institute of Clinical Medicine University of Oslo Oslo Norway
3. Department of Ophthalmology University Medical Center Groningen University of Groningen Groningen The Netherlands
4. Department of Plastic and Reconstructive Surgery Oslo University Hospital Oslo Norway
5. Department of Ophthalmology Faculty of Health Sciences Institute for Clinical and Experimental Medicine Linköping University Linköping Sweden
6. Department of Ophthalmology Sørlandet Hospital Arendal Arendal Norway
7. School of Optometry College of Health & Life Sciences Aston University Birmingham UK
8. Department of Ophthalmology New Zealand National Eye Centre The University of Auckland Auckland New Zealand
9. Department of Ophthalmology Harvard Medical School Schepens Eye Research Institute/Massachusetts Eye and EarBoston Massachusetts USA
10. Department of Ophthalmology Vestfold Hospital Trust Tønsberg Norway
11. Department of Epidemiology University Medical Center Groningen University of Groningen Groningen The Netherlands
12. Dutch Dry Eye Clinic Velp The Netherlands
13. Department of Ophthalmology Oslo University Hospital Oslo Norway
14. Department of Ophthalmology Stavanger University Hospital Oslo Norway