3-year Outcomes of Botulinum Toxin versus Strabismus Surgery for the Treatment of Acute Acquired Comitant Esotropia in Children.

Abstract

Introduction: Botulinum toxin is an alternative to conventional strabismus surgery for treatment for acute, acquired, comitant esotropia (AACE). Previous studies suggest that the two treatment approaches may be equally effective for 6 months. The purpose of our study was to determine whether botulinum toxin remains as effective as strabismus surgery for 36 months after treatment.

Methods: Design: Multicenter, retrospective, nonrandomized, comparative, clinical, non-inferiority study.

Setting: Two tertiary care pediatric hospitals.

Study population: 76 children with AACE followed for at least 36 months after treatment.

Intervention: Treatment with either botulinum toxin ('BTX group') or strabismus surgery ('surgery group').

Main outcome measure: Success rate at 36 months (horizontal deviation of 10 prism diopters or less and evidence of binocular vision).

Results: There were 44 patients in the BTX group and 32 patients in the surgery group with a median deviation of 35 PD in both groups (range 10-55). The duration of general anesthesia (6 vs 71 min, P<0.0001) and time in the post-anesthesia care unit (40 vs 95 min, P<0.0001) were significantly shorter in the BTX group. At 36 months, the success rate was 72% in the BTX group and 56% in the surgery group with a similar median deviation and median stereoacuity. BTX was non-inferior to surgery at 36 months (95%CI for difference in success rate (BTX minus surgery) was -5% to +38%). At 36 months, the median time from esotropia onset to any intervention was 6.5 months without treatment success and 4 months in those with treatment success (P<0.05).

Conclusions/relevance: Botulinum toxin was non-inferior to strabismus surgery in the treatment of AACE at 36 months while reducing the duration of general anesthesia. Longer delay from esotropia onset to treatment was an independent risk factor for worse sensorimotor outcomes irresepctive of the type of treatment.