1. Department of Ophthalmology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway
2. University of Oslo, Oslo, Norway
3. Department of Ophthalmology, Oslo University Hospital, Oslo, Norway
4. Oslo Centre for Biostatistics and Epidemiology, Department of Biostatistics, University of Oslo, Norway
5. Department of Medical Biochemistry, Oslo University Hospital, Oslo, Norway