Fig. 8 Illustration showing the technique for botulinum A toxin injection plus transposition surgery for chronic sixth-nerve palsies. Botulinum A toxin is injected into the medial rectus muscle prior to or at the time of surgery. A full tendon transposition of the superior and inferior rectus to the involved lateral rectus is performed. Note that the transposed muscles are sutured adjacent to the lateral rectus insertion rather than perpendicular to it. (McManaway JW, Buckley EG, Brodsky MC: Vertical rectus muscle transposition with intraoperative botulinum injection for treatment of chronic sixth nerve palsy. Graefes Arch Clin Exp Ophthalmol 228:402, 1990)