1. Department of Neuromedicine and Movement Science Norwegian University of Science and Technology (NTNU) Trondheim Norway
2. Public Health Unit Finnish Institute for Health and Welfare Helsinki/Oulu Finland
3. Department of Ophthalmology Helsinki University Hospital Helsinki Finland
4. Department of Ophthalmology, St. Olavs Hospital Trondheim University Hospital Trondheim Norway
5. Department of Clinical and Molecular Medicine NTNU Trondheim Norway
6. Children's Clinic, St. Olavs Hospital Trondheim University Hospital Trondheim Norway
7. Department of Rehabilitation Science and Health Technology Oslo Metropolitan University Oslo Norway
8. Clinical Medicine Research Unit, Oulu University Hospital University of Oulu Oulu Finland
9. Children's Hospital Helsinki University Hospital Helsinki Finland
10. University of Helsinki Helsinki Finland