[1] Qingdao Univ, Affiliated Hosp, Dept Geriatr Med, 16 Jiangsu Rd, Qingdao 266000, Shandong, Peoples R China
[2] Qingdao Univ, Affiliated Hosp, Dept Neurol, 16 Jiangsu Rd, Qingdao 266000, Shandong, Peoples R China
[3] Qinghai Univ, Dept Grad Sch, Xining 810016, Qinghai, Peoples R China
[4] Gaomi Municipal Hosp, Dept Radiol, Gaomi 261500, Shandong, Peoples R China
[5] Yijishan Hosp, Wannan Med Coll, Dept Ophthalmol, Wuhu 241000, Peoples R China