Clinical efficacy, safety, and success factors of botulinum toxin type A in the treatment of acute acquired comitant esotropia

PURPOSE: Acute acquired comitant esotropia (AACE) is an increasingly reported form of esotropia, possibly linked to the rising use of digital devices. Botulinum toxin type A (BTXA) has emerged as a minimally invasive treatment alternative to surgery, particularly for patients with diplopia. We aimed to investigate the efficacy and safety of BTXA injections in treating AACE while identifying factors contributing to successful treatment outcomes. STUDY DESIGN: A retrospective, single-center study. METHODS: This study retrospectively evaluated 228 patients with AACE who received BTXA injections at a single center. Treatment outcomes, adverse events, and factors influencing success were analyzed. Successful outcomes were defined as either the absence of diplopia in the primary position or an angle of deviation of ≤10 prism diopters from orthotropia, both evaluated at more than 6 months after the last injection. RESULTS: The average patient age was 30.9 years, and 52% achieved successful outcomes. Transient adverse events, including blepharoptosis (24%) and hypertropia (16%), were observed. The study found that shorter duration from onset to treatment (P = 0.018) and post-treatment overcorrection (P = 0.0073) were associated with higher success rates. Although some patients required additional treatment or surgery due to recurrence, BTXA was an effective intervention for AACE, with a significant improvement in eye alignment and stereopsis. CONCLUSION: Early intervention with BTXA is crucial for successful outcomes and offers a safe, less invasive alternative to traditional strabismus surgery.