1. Department of Endocrinology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
2. Department of Internal Neurology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
3. Department of Physiology, Medical University, Shijiazhuang, Hebei 050017, P.R. China
4. Department of Ophthalmology, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China