1. Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
2. Department of Cell and Developmental Biology, Faculty of Biology, Sofia University “St. Kliment Ohridski”, 1164 Sofia, Bulgaria
3. Department of Optics and Spectroscopy, Faculty of Physics, Sofia University “St. Kliment Ohridski”, 1164 Sofia, Bulgaria