1. School of Pharmacy, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
2. Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland
3. Ophthalmology, University of Helsinki and Helsinki University Hospital, Haartmaninkatu 8, FI-00290 Helsinki, Finland
4. Faculty of Pharmacy, University of Helsinki, FI-00790 Helsinki, Finland