Acquired Comitant Esotropia following Botulinum Toxin Injection: A Brief Case Series

Diplopia is an uncommon but well described side effect of botulinum toxin treatment to the eyelids with an incidence ranging from 1.7 to 2.1%, with small cohorts reporting as high as 14%[1]. Diplopia is typically transient and has been previously described as the result of paresis of one of the extraocular muscles due to diffusion of toxin beyond the orbital septum[2] and most commonly involves the inferior oblique[3] and less frequently the inferior, superior, and lateral rectus[4] leaving an incomitant deviation. To contrast this, we are presenting three cases of comitant esotropia following injection of botulinum toxin to the eyelids and periocular areas.