Anterior transposition of the superior oblique tendon in the treatment of oculomotor nerve palsy and its influence on postoperative hypertropia

Purpose: To determine whether postoperative hypertropia after anterior tran sposition of the superior oblique tendon without trochleotomy could be avoi ded with a simplified surgical approach. Methods: Eight patients with oculomotor nerve palsy tone patient was bilate rally affected) were retrospectively identified as having undergone anterio r transposition of the superior oblique tendon without trochleotomy or vert ical rectus muscle surgery between March 1992 and September 1998. The super ior oblique tendon was cut at the medial border of the superior rectus musc le and placed 13.5 mm anterior to the medial insertion of the superior rect us muscle in each of these patients. Resection of the superior oblique tend on was not performed. The lateral rectus muscle was weakened, and no vertic al rectus muscles were resected. Results: Preoperative deviations with the uninvolved eye fixating in primar y position ranged from 20-90 prism diopters (Delta) of exotropia (mean: 49. 3 Delta) and from 0-20 Delta of hypotropia (mean: 11.25 Delta). Postoperati ve horizontal deviations in the primary gaze position ranged from 12 Delta of exotropia to 20 Delta of esotropia. Six cases were aligned within 10 Del ta of exotropia or esotropia. Postoperative vertical deviations in the prim ary gaze position ranged from 2 Delta of hypertropia to 8 a of hypotropia. Six cases were aligned within 2 Delta of deviation. Significant postoperati ve restrictive hypertropia, or new postoperative paradoxical ocular movemen ts, did not occur in any patient. Patients who underwent follow-up >4 month s maintained stable eye alignment, Conclusion: Transposition of the superior oblique tendon without simultaneo us resection or trochleotomy, or additional surgery to the vertical rectus muscle simplifies the surgical technique and eliminates subjective decision making regarding the amount of resection.