1. Beijing Institute of Ophthalmology; Beijing Tongren Hospital; Capital Medical University; Beijing China
2. School of Public Health; Capital Medical University; Beijing China
3. Beijing Key Laboratory of Epidemiology; Capital Medical University; Beijing China
4. Beijing Center for Disease Prevention and Control; Beijing China
5. School of Medical Science; Edith Cowan University; Perth Western Australia Australia
6. Department of Ophthalmology; Medical Faculty Mannheim of the Ruprecht-Karls-University Heidelberg; Heidelberg Germany