1. Department of General Practice and Primary Health Care University of Helsinki and Helsinki University Hospital Helsinki Finland
2. Folkhälsan Research Center Helsinki Finland
3. Gerontology Research Center Faculty of Sport and Health Sciences University of Jyväskylä Jyväskylä Finland
4. Division of Epidemiology and Clinical Applications Intramural Research Program National Eye Institute National Institutes of Health Bethesda Maryland USA
5. Faculty of Medicine University of Iceland Reykjavik Iceland
6. Department of Ophthalmology Landspitali, The National University Hospital of Iceland Reykjavik Iceland
7. Icelandic Heart Association Kópavogur Iceland