Abducens paralysis repaired with muscle transposition and intraoperative botulinum toxin.

Surgical management of abducens paralysis has been modified frequently since the turn of the century in a continuing effort to produce not only orthotropia in the primary position but good or excellent abduction. We report a bilateral case repaired surgically by a single, whole-muscle, superior rectus transposition. Secondary medial rectus contracture, a common problem, is usually managed by surgical weakening procedures which it is difficult, if not impossible, to grade. We attempted to avoid the problem by weakening the antagonist medial rectus by intraoperative injection of botulinum toxin which might allow a self-adjusting mechanism. Using this approach, fusion in down-gaze without correction and in the primary position with a small amount of vertical and horizontal prism correction was achieved. Good to excellent abduction was restored.