Long-term treatment with botulinum toxin supported as nonsurgical option for managing strabismus in adults

J AAPOS. 2008;12(6):569-575.

No significant adverse effects were seen with long-term (3 to 22 years) management of strabismus with repeated injections of botulinum toxin.

In a retrospective review of adults with strabismus managed with botulinum injections, researchers found that the angle of deviation tends to decrease and that the interval between injections tends to increase over time.

Botulinum toxin may be offered as an alternative to surgery in the United Kingdom, where the study was undertaken. In comparing two groups, those receiving 25 or more injections and those receiving fewer than 25 injections, there were no statistically significant differences between age at first injection, sex, site injected, diagnosis or complication rate. The most frequently recorded diagnosis in both groups was consecutive exotropia, although the distribution of underlying diagnoses between the two groups was significantly different (P = .001). In the long-term group, patients had undergone more previous operations (P = .001) and had a lower degree of binocularity (P = .001).

"The treatment of strabismus with botulinum toxin on a long-term basis is practicable and valuable in patients with poor binocular potential, complicated strabismus, or multiple previous strabismus operations," the study authors said.