1. The Norwegian Dry Eye Clinic, 0366 Oslo, Norway
2. Department of Medical Biochemistry, Oslo University Hospital, 0450 Oslo, Norway
3. Department of Computer Science, Oslo Metropolitan University, 0130 Oslo, Norway
4. Department of Oral Surgery and Oral Medicine, Faculty of Dentistry, University of Oslo, 0313 Oslo, Norway
5. Department of Ophthalmology, Drammen Hospital Trust, 3004 Drammen, Norway
6. Department of Ophthalmology, Sørlandet Hospital Trust, 4838 Arendal, Norway
7. Department of Ophthalmology, Oslo University Hospital, 0450 Oslo, Norway
8. Departments of Ophthalmology and Epidemiology, University Medical Center Groningen, 9713 Groningen, The Netherlands
9. Schepens Eye Research Institute/Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, 20 Staniford St., Boston, MA 02114, USA
10. Department of Oral Biology, Faculty of Dentistry, University of Oslo, 0313 Oslo, Norway