1. Department of Health and Welfare Services, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama 351-0197, Japan
2. The University of Fukuchiyama, 3370, Aza Hori, Fukuchiyama-shi, Kyoto 620-0886, Japan
3. Department of Ophthalmology, Juntendo University School of Medicine, 3-1-3, Hongo, Bunkyo-ku, Tokyo 113-8431, Japan