Effectiveness of disinsertion-resection and tucking of the inferior oblique muscle in patients with unilateral long-standing superior oblique muscle palsy.

PURPOSE: To investigate the effectiveness and safety of disinsertion-resection and tucking of the inferior oblique muscle in patients with unilateral long-standing superior oblique muscle palsy and secondary inferior oblique muscle overaction.
METHODS: Between April 2000 and January 2005, the records of 31 patients who underwent disinsertion-resection and tucking of the inferior oblique muscle for treatment of unilateral long-standing (> 6 months) superior oblique muscle palsy were retrospectively reviewed. A comprehensive ocular examination including best-corrected visual acuity measurements, ductions, versions, and deviations at near and distance in the diagnostic positions of gaze, head tilt test, abnormal head position, dilated fundus, field of binocular fixation, and Lee screen test was performed prior to and after surgery.
RESULTS: All patients had Knapp's class I unilateral superior oblique muscle palsy. The mean preoperative score of inferior oblique muscle overaction was +3.03 and the mean vertical deviation was 15.9 PD in primary position. The follow-up period ranged from 4 to 82 months. Inferior oblique muscle overaction diminished in 29 patients, and 2 patients had +1.0 overaction in adduction of the affected eye. The vertical deviation in these patients had some residual but smaller hypertropia.
CONCLUSIONS: Disinsertion-resection and tucking of the inferior oblique muscle was safe, simple, and effective in eliminating inferior oblique muscle overaction and abnormal head posture, and in reducing the hyperdeviation in patients with unilateral long-standing superior oblique muscle palsy.