1. Department of Ophthalmology; Kuopio University Hospital; Kuopio Finland
2. Department of Clinical Neurophysiology; Institute of Clinical Medicine; University of Eastern Finland; Kuopio Finland
3. Department of Health Sciences; University of Jyväskylä; Jyväskylä Finland
4. Department of Ophthalmology; Institute of Clinical Medicine; University of Eastern Finland; Kuopio Finland