The efficacy of botulinum toxin treatment for children with a persistent esotropia following bilateral medial rectus recessions and lateral rectus resections.

BACKGROUND AND PURPOSE To report on the outcomes of treating children with a persistent esotropia with an injection of botulinum toxin in a medial rectus muscle. PATIENTS AND METHODS The medical records were reviewed of all children at one institution with a persistent esotropia after bilateral medial rectus recessions and bilateral lateral rectus resections then treated with a botulinum toxin injection. RESULTS Five patients with a mean preoperative esotropia of 37Δ (range 25–50Δ) underwent bilateral medial rectus recessions and then bilateral lateral rectus resections. Their residual esotropia (mean of 25Δ; range 18–35Δ) was then treated with a single injection of 3–5 units of botulinum toxin into one medial rectus muscle. The patients were then followed for a mean of 34 months (range 14–79 months). At last follow-up, two patients had an esotropia <10Δ. The other three patients had no long-term improvement in their ocular alignment. Two of these patients then underwent additional strabismus surgery. In both cases, they then developed a consecutive exotropia. CONCLUSION Treatment with a single injection of botulinum toxin was beneficial in 2 of 5 children. Botulinum toxin treatment alone did not result in a consecutive exotropia in any patients treated.