To assess the efficacy of botulinum toxin (Novotox) injection in patients with cerebral palsy (CP) and esotropia.

In a non-comparative, prospective interventional case series botulinum toxin injection was done in 44 patients with CP and esotropia. Botulinum toxin was injected in both medial rectus muscles of all patients and was repeated in 12 patients. Angle of deviation within 10 prism diopters (PD) of orthotropia was defined as a successful outcome.

Forty-four patients (21 males) with the mean age of 47.56 ± 35.86 months were included in the study. The mean esotropia in all patients was 52.27 ± 18.40 PD (25–123 PD). The range of follow-up was 12–24 months. Thirty patients (68.18%) were treated successfully one year after surgery. The rates of success, consecutive exotropia, and residual esotropia were 61.4%, 13.63%, and 25% in the last follow-up, respectively. The logistic regression showed statistically significant associations between success and lower age, higher pre-injection deviation, one month post-injection deviation, and severe ptosis. Complications included subconjunctival hemorrhage and ptosis.

Botulinum toxin injection is reasonably less invasive with light anesthesia, scar free, and a therapeutic alternative for the patient with esotropia and CP. Therefore, it can provide more possible surgical options in future.