1. Clinical Medical College, Ningxia Medical University, Yinchuan, Ningxia, China
2. Department of Ophthalmology, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China
3. Shaanxi Eye Hospital, Xi’an People’s Hospital(Xi’an Fourth Hospital, The People’s Hospital Affiliated to Northwest University), Xi’an, Shaanxi, China