[1] Hallym Univ, Chuncheon Sacred Heart Hosp, Dept Neurosurg, Chunchon, South Korea
[2] Seoul Natl Univ, Bundang Hosp, Dept Ophthalmol, Songnam 463707, South Korea
[3] Seoul Natl Univ, Bundang Hosp, Dept Radiol, Songnam 463707, South Korea
[4] Seoul Natl Univ, Bundang Hosp, Dept Neurosurg, Songnam 463707, South Korea