1. Department of Ophthalmology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, People's Republic of China
2. National School of Development, Peking University, Beijing, People's Republic of China
3. Northwestern University School of Medicine, Chicago, IL, USA
4. Hangzhou Vocational and Technical College, Hangzhou, People's Republic of China
5. Center for Disease Control and Prevention of Jinyun County, Jinyun, Zhejiang Province, People's Republic of China
6. Zhejiang Provincial Center for Disease Control and Prevention of Hangzhou, Hanzhou, People's Republic of China
7. Department of Ophthalmology, Central Hospital of Jinyun County, Jinyun, People's Republic of China
8. Center for Preventive Ophthalmology and Biostatistics, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA