Assessment of torsion after superior rectus transposition with or without medial rectus recession for Duane syndrome and abducens nerve palsy

BackgroundSuperior rectus transposition with or without medial rectus recession has been advocated for the treatment of abducens nerve palsy and esotropic Duane syndrome. Early reports have focused mainly on postoperative ocular alignment, but there is concern that superior rectus transposition may induce torsional misalignment. The purpose of this study was to evaluate torsional outcomes after superior rectus transposition surgery using prospective preoperative and postoperative torsional assessments.MethodsProspective measurements were performed on all patients undergoing superior rectus transposition. Preverbal infants were assessed using fundus torsion evaluating the position of the fovea relative to the optic nerve; older children/adults underwent double Maddox rod (DMR) assessment of torsion.ResultsA total of 11 subjects met the study inclusion criteria. The etiology of strabismus was an abducens nerve palsy (n = 7) or Duane syndrome (n = 4). For the subjects evaluated by fundus torsion (n = 4), there was no significant change in torsion for 3 (75%). For those subjects undergoing DMR (n = 7), there was a significant change in subjective torsion (4.7 ± 3.8°excyclotorsion vs 0.0° ± 5.0° excyclotorsion; P = 0.004). Esotropic deviation improved significantly for all subjects (39Δ ± 23Δ vs 6.5Δ ± 13Δ; P = 0.001) and no significant mean vertical deviation postoperatively, although 1 patient had a clinically significant postoperative hypertropia measuring 14Δ. Abduction also improved significantly (−4.2 ± 0.9 vs −2.8 ± 1, P = 0.0001).ConclusionsIn this patient series, superior rectus transposition with medial rectus recession did not have clinically significant induction of torsional diplopia as a result of the procedure.