1. Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, 81 Meishan Road, Hefei, Anhui 230032, China
2. Department of Ophthalmology, The First Affiliated Hospital of Anhui Medical University, Hefei, 218 Jixi Road, Hefei, Anhui 230022, China
3. Department of Ophthalmology, The Hospital of University of Science and Technology of China, Jinzhai Road, Hefei, Anhui 230026, China