Outcome of Botox Injection in Partially Accommodative Esotropia Compared to Medial Rectus Recession

Purpose: To compare the effectiveness of botulinum toxin (BTX) injection to bilateral medial rectus recession (BMR) in partially accommodative esotropia (PAET). Methods: This retrospective study reviewed the medical records of 107 children younger than 15 years of age treated for PAET with BTX injection or bilateral medial rectus recession (BMR) surgery at a single institution between 2015 and 2022. PAET was defined as residual esotropia of at least 14 prism diopters (PD) after six weeks of continuous wear of full cycloplegic refraction. Primary success was defined as a distance alignment of ≤ 10 PD after a single treatment (BTX injection or BMR surgery). Secondary success was defined as achieving this alignment after repeated treatment. Results: Of 107 patients, 51 received BTX injection and 56 underwent surgery. The surgery group had a significantly higher primary success rate (83.9%) than the BTX injection group (50.9%). No demographic factors correlated with treatment success. After repeat interventions, the cumulative success rate rose to 78.4% in the BTX injection group and 87.5% in the surgery group. Six patients (11.7%) in the BTX injection group eventually required surgical intervention. The complications rate was 4.8% in the BTX injection group (temporary ptosis covering visual axis), and 3.57% in the surgery group (consecutive exotropia necessitating medial rectus advancement). Conclusion: Surgical intervention (BMR surgery) demonstrated significantly higher primary success rates for PAET than a single BTX injection. However, repeated BTX injections ultimately achieved comparable long-term success rates. While BTX offers less invasiveness and reduced anesthesia time, the potential need for multiple injections should be considered when counseling patients and their families.