1 Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, SwedenDepartment of Medical Biochemistry, Oslo University Hospital, Oslo, NorwaySchepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USADepartment of Ophthalmology, Innland Hospital, Elverum, NorwaySynslaser Kirurgi AS, Oslo, Norway.