Botulinum Toxin-Augmentation of Strabismus Surgery in Large-Angle, Infantile Esotropia
Michael J. Wan; Aubrey Gilbert; Melanie Kazlas; Carolyn Wu; Iason S. Mantagos; David G. Hunter; Ankoor S. Shah
Boston Children’s Hospital
Introduction: The purpose of this study was to determine whether botulinum toxin augments the effect of strabismus surgery in pediatric patients with large-angle, infantile esotropia.
Methods: This was a retrospective, non-randomized, comparative cohort study at a tertiary-care pediatric hospital. Patients who underwent treatment with botulinum toxin-augmented bilateral medial rectus recessions (‘augmented-surgery group’) were compared to patients who underwent traditional bilateral medial rectus recessions (‘surgery-only group’). The main outcome measure was the effect of surgery on ocular alignment, measured in prism diopters of change per mm of surgery (PD/mm).
Results: There were 14 patients in the augmented-surgery group and 16 patients in the surgery-only group. The mean effect on alignment was significantly greater in the augmented-surgery group compared to the surgery-only group at 4 months (5.7 vs 4.0 PD/mm, p = 0.002) and at 1 year (5.4 vs 3.7 PD/mm, p = 0.002). There was a partial loss of treatment effect between 4 months and 1 year in both groups, which was similar in magnitude (p = 0.57). On linear regression, there was a trend toward a positive correlation between botulinum toxin dose and treatment effect, but this was not statistically significant (p = 0.09).
Discussion: Botulinum toxin augments the effect of bilateral medial rectus recessions by approximately 40% in large-angle, infantile esotropia. The augmentation effect is maintained for at least a year after surgery. A surgical dosing table is proposed for this technique.
Conclusion: Botulinum toxin-augmented surgery may be an alternative to traditional options for large-angle, infantile esotropia.
References: 1. Khan AO. Two horizontal rectus eye muscle surgery combined with botulinum toxin for the treatment of very large angle esotropia. A pilot study. Binocul Vis Strabismus Q 2005; 20(1):15-20.
2. Lueder GT, Galli M, Tychsen L, Yildirim C, Pegado V. Long-term results of botulinum toxin-augmented medial rectus recessions for large-angle infantile esotropia. Am J Ophthalmol 2012; 153(3):560-3.