1. Department of Ophthalmology St. Olavs Hospital Trondheim University Hospital Trondheim Norway
2. Department of Neuromedicine and Movement Science Norwegian University of Science and Technology Trondheim Norway
3. Department of Public Health and Nursing Norwegian University of Science and Technology Trondheim Norway
4. Department of Ophthalmology Zealand University Hospital Roskilde Denmark
5. Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark