Botulinum toxin treatment of sixth cranial nerve palsy.

ABSTRACT

Twelve patients with sixth cranial nerve palsy were treated with botulinum toxin injections to the antagonist medial rectus muscle at Siriraj Hospital between October 1995 and June 1996, The angle of esotropia, the extent of abduction and stereopsis were measured in all patients before and after the injections. After the treatment, seven patients (58.3 per cent) who exhibited a short duration of palsy, small angle of esotropia and incomplete paresis of the lateral rectus muscle recovered to achieve orthotropia and re-established fusion in the primary position. Of those seven patients, five demonstrated complete recovery of ocular motility. Botulinum toxin treatment can not only be a safe and effective alternative to conventional surgery but can also restore single binocular vision in primary gaze.