Anterior and nasal transposition of inferior oblique muscle in cases of superior oblique palsy

Abstract

To report long-term outcome of inferior oblique anterior and nasal transposition in superior oblique palsy. The medical records of patients with superior oblique palsy who underwent inferior oblique anterior nasal transposition were reviewed retrospectively. A comprehensive ophthalmic evaluation, including prism bar cover test and measurement of torsion, was performed for all cases. One-year postoperative results were evaluated for alignment in primary gaze, contralateral gaze, and upgaze; reduction in inferior oblique overaction and changes in fundus torsion to assess long-term outcome of the procedure. A total of 12 patients were included. Three cases also underwent horizontal muscle surgery. Mean age at the time of surgery was 20.6years. The median preoperative hypertropia was 21.5Δ (range, 12Δ-36Δ), corrected to 4.5Δ (range, 2Δ-10Δ) at 12months postoperatively (P=0.002). Median inferior oblique overaction decreased from +3 (range, +1 to +4) to 0 (range, -1 to +1). Preoperative fundus extorsion was 19.2° ± 6.7°; postoperative, 0.58° ± 1.8° (P<0.001). No consecutive hypotropia or underaction in elevation was observed in 10patients; 1 patient complained of torsional diplopia in upgaze. Extorsion was eliminated and head tilt improved in all patients. Inferior oblique anterior and nasal transposition resulted in good long-term outcomes in our patients with superior oblique palsy presenting with hypertropia, inferior oblique overaction, and extorsion in primary gaze.