1. Department of Ophthalmology, The Second Hospital of Jilin University, No.218, Ziqiang Street, Nanguan District, Changchun, Jilin, P.R. China
2. Department of Ophthalmology, Liaoyuan People’s Hospital, No. 188, Kuangdian West Street, Xi’an District, Liaoyuan, Jilin, P.R. China
3. Department of Ophthalmology, Baotou Eye Hospital, No. 28, Hada Road, Qingshan District, Baotou, Inner Mongolia Autonomous Region, P.R. China