1. Research Unit of Clinical Medicine, University of Oulu, Oulu, Finland
2. Medical Research Center, Oulu University Hospital, Oulu, Finland
3. Department of Ophthalmology, Oulu University Hospital, Oulu, Finland
4. Research Service Unit, Oulu University Hospital, Oulu, Finland
5. The Research Unit of Surgery, Anesthesia and Intensive Care, Oulu University Hospital and University of Oulu, Oulu, Finland