[1] WILLS EYE HOSP & RES INST, NEUROOPHTHALMOL SERV, PHILADELPHIA, PA 19107 USA
[2] GRAD HOSP PHILADELPHIA, DEPT OPHTHALMOL, PHILADELPHIA, PA 19146 USA
[3] UNIV PENN, OPHTHALMOL, PHILADELPHIA, PA 19104 USA
[4] THOMAS JEFFERSON UNIV, OPHTHALMOL, PHILADELPHIA, PA 19107 USA
[5] WILLS EYE HOSP & RES INST, ORBITAL UNIT, PHILADELPHIA, PA 19107 USA
[6] MASSACHUSETTS EYE & EAR HOSP, BOSTON, MA 02114 USA