[1] Capital Med Univ, Xuan Wu Hosp, Dept Ophthalmol, Beijing 100053, Peoples R China
[2] Capital Med Univ, Xuan Wu Hosp, Dept Neurol, Beijing 100053, Peoples R China
[3] Capital Med Univ, Xuan Wu Hosp, Ctr Lab, Beijing 100053, Peoples R China
[4] Univ London Imperial Coll Sci Technol & Med, Chelsea & Westminster Hosp, Dept Surg & Canc, London SW10 9NH, England