Botulinum Toxin-Augmented Strabismus Surgery versus Conventional Surgery in the Treatment of Large-Angle Infantile Esotropia

Abstract

Purpose: The treatment of large-angle infantile esotropia remains a challenge. Surgical treatment traditionally has involved either three-muscle surgery or supra-maximal medial rectus recessions, but both methods have significant drawbacks including risk of over- or undercorrection. An alternative is to use botulinum toxin to weaken the medial rectus muscles, but multiple treatments are often required and the success rate for large deviations is poor. It has been suggested that the best approach may be to combine these treatments. No previous study has directly compared botulinum toxin-augmented surgery to conventional surgery alone.

Methods: A retrospective, comparative study was completed evaluating baseline characteristics and outcomes of consecutive patients with large-angle infantile esotropia (55 prism diopters(^Δ) or greater) who underwent either conventional or botulinum toxin-augmented strabismus surgery. The primary outcome measure was post-operative deviation and need for retreatment within one year of initial intervention. Success was defined as a deviation <10^Δ and no retreatment at 1 year after the initial intervention.

Results: The record review identified 38 patients meeting inclusion criteria, of whom 14 had been treated with botulinum toxin-augmented surgery and 24 with bilateral medial rectus recessions. Prior to surgery, the augmented group had a larger median angle of deviation (65 versus 60^Δ, p = 0.006) and less recession of the medial rectus muscles was performed (5.5 versus 6.0 mm, p = 0.005). The augmented group had greater success at 1 year (70% versus 30%, p = 0.035). The augmented group also had a significantly smaller median angle of deviation at 1 year (0 versus 18^Δ, p = 0.026). There were no serious complications in either group.

Conclusions: Botulinum toxin can significantly augment the effect of medial rectus recessions and improve the success of strabismus surgery in patients with large-angle infantile esotropia.