Long-Term Effects of Botulinum Toxin A Versus Incisional Surgery for Management of Partially Accommodative Esotropia in Children: Comparison of Three Approaches.

[PURPOSE] To compare the effect of bilateral medial rectus injection of botulinum toxin A (BTX-A), bilateral medial rectus muscle recession surgery (BMR rc), or unilateral medial rectus muscle recession combined with lateral rectus muscle resection surgery (R&R), in the management of partially accommodative esotropia (PAET) in children.

[DESIGN] Retrospective comparative clinical study.

[METHODS] The study cohort included 98 patients diagnosed with PAET who had BTX-A injection or incisional surgery between December 2014 and January 2023. The main outcome measures included motor and sensory results as well as complications. Follow-up was at least 12 months for all patients.

[RESULTS] There were 28 patients in the BTX-A group, 45 in the R&R group, and 25 in the BMR rc group. The motor success rates at distance and near fixation respectively were 50% (14/28) and 54% (15/28) in the BTX-A group, which were lower than that of the R&R group (78% [35/45], 84% [38/45]) and the BMR rc group (72% [18/25], 84% [21/25]) (P = .042 for near and P = .006 for distance). For patients with onset age <2.5 years old, there was no statistical difference amongst the 3 surgical approaches (P = .656). For patients with onset age ≥2.5 years, the motor success rate of the R&R group (81% [26/32]) and the BMR rc group (88% [14/16]) was higher than that in the BTX-A group (38% [5/13]; P = .004). There was no statistical difference in sensory outcomes for patients regardless of onset age or treatment methods (P > .05 for all). During follow-up, 4% (2/45) of patients in the R&R group and 20% (5/25) in the BMR rc group developed consecutive exotropia; no patient in the BTX-A group was overcorrected (P = .017).

[CONCLUSIONS] Bilateral medial rectus muscle injection with BTX-A in patients with PAET is a safe, accessible, and low-cost alternative. Although motor success rates were higher, overall, in patients treated with incisional surgery, for patients with earlier age of onset (≤ 2.5 years old), BTX-A injection may be preferred to incisional surgery. In older children treated with unilateral recession-resection surgery, fewer developed consecutive exotropia.