1 Department of Neurology, The First Affiliated Hospital of Northwest University, Xi'an, Shaanxi Province, People's Republic of China.
2 Department of Neuro-Ophthalmology, The First Affiliated Hospital of Northwest University, Xi'an, Shaanxi Province, People's Republic of China.
3 Department of Neurology, The First Affiliated Hospital of Northwest University, Xi'an, Shaanxi Province, People's Republic of China. wusongdi@gmail.com.
4 Department of Neuro-Ophthalmology, The First Affiliated Hospital of Northwest University, Xi'an, Shaanxi Province, People's Republic of China. wusongdi@gmail.com.