1. Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Inohana 1-8-1, Chuo-ku, Chiba, Chiba 260-8670, Japan
2. Department of Surgical Pathology, Chiba Cancer Center, Nitona-cho 666-2, Chuo-ku, Chiba, Chiba 260-8717, Japan