1. From the Joint Shantou International Eye Center, Shantou University and Chinese University of Hong Kong, Shantou, Peoples Republic of China; the2Department of Ophthalmology and Visual Science, Chinese University of Hong Kong, Hong Kong SAR, Peoples Republ
2. From the Joint Shantou International Eye Center, Shantou University and Chinese University of Hong Kong, Shantou, Peoples Republic of China; the
3. Centre for Epidemiology and Biostatistics, Chinese University of Hong Kong School of Public Health, Hong Kong SAR, Peoples Republic of China; the
4. Shantou University School of Public Health, Shantou, Peoples Republic of China;
5. Department of Ophthalmology and Visual Science, Chinese University of Hong Kong, Hong Kong SAR, Peoples Republic of China; the5Department of Public Health, Oxford University, Oxford, United Kingdom; and the
6. Xichang Eye Center, Xichang, Peoples Republic of China.