[1] Univ Penn, Sch Med, Childrens Hosp, Neuroophthalmol Serv, Philadelphia, PA 19104 USA
[2] Univ Penn, Sch Med, Childrens Hosp, Serv Neurooncol, Philadelphia, PA 19104 USA
[3] Univ Penn, Sch Med, Childrens Hosp, Serv Pathol, Philadelphia, PA 19104 USA
[4] Univ Penn, Sch Med, Childrens Hosp, Serv Neuroradiol, Philadelphia, PA 19104 USA
[5] Univ Penn, Sch Med, Childrens Hosp, Neurosurg Serv, Philadelphia, PA 19104 USA
[6] Univ Arkansas Med Sci, Dept Ophthalmol, Little Rock, AR 72205 USA
[7] Univ Arkansas Med Sci, Dept Neurosurg, Little Rock, AR 72205 USA