1. Department of Ophthalmology, The Second Affiliated Hospital of Xi’an Medical University, Xi’an, P. R. China
2. Shaanxi Eye Hospital, Xi’an People’s Hospital Xi’an Fourth Hospital, Affiliated People’s Hospital of Northwest University, Xi’an, P. R. China
3. Department of Neurology, The Second Affiliated Hospital of Xi’an Medical University, Xi’an, P. R. China
4. Department of Ophthalmology, Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine, Xianyang, P. R. China.