To what extent may Botulinum toxin type A injections be an alternative choice to surgery in infantile esotropia?

Evaluation of a single injection of botulinum toxin A in infantile esotropia as an alternative choice to surgery in a retrospective cases serie.

Patients (65 consecutive children aged 9 to 26 months with infantile strabismus) underwent botulinum toxin A injection in both medial recti Botulinum toxin A injection. Clinical datas including measurement of angle of deviation before and after injection. visual acuity, stereoscopy and side effects were observed in a 24 months period of follow-up.

Stable satisfactory result (angle equal to or less than 8 dioptres) was obtained in 33 cases (50.7%). Excellent result (-2 to + 4 dioptres) were obtained in 17 children (26%). Additional surgery was required in 32 cases for a residual (albeit smaller angle than the initial deviation) or recurrent deviation and/or DVD (49,2%).

Botulinum toxin A reduces the tonic spastic motor component of strabismus and, should additional surgery be required (49% in our series), allows the procedure to be carried out on a smaller angle. A reduction in the maximum angle of deviation is thus achieved sooner, and allows the development of anomalous binocularity in a stable microtropia.