Botulinum toxin injection into the superior rectus for treatment of strabismus

Abstract

Botulinum toxin injected into the superior rectus (SR) has rarely been described in the literature. We conducted a database search to identify all cases of SR toxin from 1982 to 2010 at our institution. Out of a total of 7575 patients in the database, only eight cases of SR toxin were identified, all of which had residual hypertropia following previous ocular surgery. This surgery comprised: retinal surgery (3 patients), strabismus surgery for thyroid eye disease (2), and transposition for VI nerve palsy (2 patients). In seven out of eight cases, a long-lasting mean reduction of 10(Δ) was achieved from between two and three injections. Ptosis occurred in all but one case, but resolved. We conclude that SR toxin injection has very limited indications, but may be considered in residual hypertropia presumed secondary to a tight or overacting SR where the patient can tolerate the temporary iatrogenic ptosis.