1. Department of Maternal, Child and Adolescent Health, Anhui Medical University School of Public Health, Hefei, Anhui 230032, China
2. Department of Health Inspection and Quarantine, Anhui Medical University School of Public Health, Hefei, Anhui 230032, China
3. Department of Ophthalmology, Second Affiliated Hospital, Anhui Medical University, Hefei, Anhui 230021, China