1. Department of Ophthalmology, the Affiliated Hospital of Qingdao University, Qingdao, Shandong Province 266003, P.R. China
2. Department of Ophthalmology, Qingdao Women and Children’s Hospital, Qingdao, Shandong Province 266034, P.R. China
3. Gout Laboratory, the Affiliated Hospital of Qingdao University, Qingdao, Shandong Province 266003, P.R. China