ABSTRACT
Introduction: We prospectively studied the use of Botulinum toxin in chronic sixth nerve palsy as part of a multi-center data collection study.
Methods: 10 patients, enrolled in 5 centers, with chronic sixth nerve palsy of greater than six months duration received Botulinum toxin alone as initial treatment. Six patients had incomplete pareses and 4 had apparent complete palsies. Two of the apparent complete palsies were excluded for analysis of outcome, due to recurrent neoplasms. Success was defined as absence of diplopia in primary position at distance fixation and partial success as within 10pd.
Results: One of eight patients (12%) was classified as a success and one (12%) as a partial success. Six patients (75%) were classified as failures. One of the apparent complete cases showed some abduction past midline after Botulinum toxin and, although classified as a failure, allowed more simple recess-resect surgery rather than a transposition.
Conclusions: Botulinum toxin is only somewhat successful in the management of chronic sixth nerve palsy. Many cases will require prism or incisional strabismus surgery to restore single binocular vision long-term. These data are useful in counselling patients and families.
