[Treatment of the comitant adquired esotropia residual deviation]

To review the therapeutic options in the management of residual esotropia, particularly focusing on the effectiveness of botulinum toxin.

Retrospective study of cases of post-surgical residual esotropia treated in our hospital from January 1999 to January 2008. Visual acuity and motor outcomes were analysed in the patients who received botulinum toxin injection.

Of the 200 cases reviewed, 91% of the patients had a new surgery, 5% of patients refused any treatment, while 8 patients (4%) received botulinum toxin injection. Visual acuity (Snellen) before surgery, before toxin and after toxin injection in the right eye was 0.77 (SD 0.2), 0.86 (SD 0.2) and 0.97 (SD 0.2), respectively, and in the left eye: 0.76 (SD 0.1), 0.91 (SD 0.09) and 0.97 (SD 0.2), respectively. The percentage net change in the angle of deviation at far and near distance after toxin injection in the last follow-up was 41.66% and 10%, respectively. The mean follow-up after botulinum toxin injenction was 30.8 months. The success rate (ocular alignment in primary eye position) after toxin at the end of follow-up was 75%.

Residual esotropia may be managed with further surgery or with botulinum toxin injection. The first option is more common, but in selected cases botulinum toxin injection may provide very successful outcomes with a low incidence of complications.