Impact of Adding Augmented Superior Rectus Transpositions to Medial Rectus Muscle Recessions When Treating Esotropic Moebius Syndrome.

Purpose: To describe outcomes after treatment of Moebius syndrome (MBS) esotropia by adjustable bilateral medial rectus recession (BMR) with and without augmented superior rectus transposition (SRT).

Design: Retrospective case series.

Methods: Patients meeting 2014 diagnostic criteria for MBS and treated at Boston Children's Hospital between 2003 and 2019 were identified via billing records and chart review. Visual acuity, sensorimotor evaluations, strabismus procedures, and other clinical features were recorded. Surgical outcomes for patients treated with strabismus surgery (excluding those with prior surgery elsewhere) were evaluated. The primary outcome measure was postoperative alignment comparing treatment by adjustable BMR vs adjustable BMR+SRT.

Results: A total of 20 patients had MBS, and 12 of these (60%) were male. Fifteen patients (75%) had primary position esotropia, and all had bilateral abduction deficit. Eight of 20 patients met inclusion criteria for primary strabismus surgery outcome. Five had undergone adjustable BMR ranging from 4.5 to 6.5 mm. Three had undergone adjustable BMR+SRT, all with 4-mm medial rectus muscle recessions. Mean preoperative esotropia before treatment by BMR was 39.5 PD (± 15 PD) with mean postoperative esotropia 9 PD (± 7.9 PD) at 6 months. Mean preoperative esotropia before treatment by BMR+SRT was 70.8 PD (± 5.9 PD) with mean postoperative esotropia 2.5 PD (± 3.5 PD) at 6 months. Significantly greater reduction in esotropia resulted from BMR+SRT than from BMR (P = .036).

Conclusions: BMR proved sufficient to treat esotropia <50 PD and BMR+SRT for greater esotropia in patients with MBS-associated abduction limitation.