Objective: To evaluate the surgical options in treating strabismus caused by different degrees of oculomotor nerve palsy.
Methods: Surgical procedures for 13 patients with unilateral oculomotor nerve palsy were retrospectively studied. Eight patients had partial paralysis with isolated or multiple muscle involvement. A greater amount of lateral rectus recession and medial rectus resection than is usual was performed in six cases; transposition combined with resection of the medial rectus was performed in two cases with limited hypotropia. Of five patients with total oculomotor nerve paralysis, three underwent transposition of the superior oblique tendon to the superior site of the medial rectus insertion. The other two patients, having total oculomotor nerve paralysis combined with trochlear nerve palsy, underwent fixation of the globe to the anterior lacrimal crest by half a tendon width of the medial rectus. Extremely large (10-12 mm) lateral rectus recessions were performed in all patients. Pre- and postoperative horizontal and vertical deviations were measured to assess the surgical outcomes.
Results: Preoperative deviations of the affected eye were exotropia of 80(Delta) to 120(Delta), five cases with hypotropia of 15(Delta) to 35(Delta), and two cases with hypertropia of 15(Delta) to 20(Delta). After 6 to 27 months of postoperative follow-up, eye alignment showed horizontal residual deviation of 0(Delta) to 20(Delta) exotropia and vertical residual deviation of 4(Delta) to 10(Delta) hypotropia.
Conclusions: By choosing the appropriate surgical procedure, eye alignment in the primary position was achieved, but recurrence of the exotropia was unavoidable, and a residual exotropia of 10(Delta) to 20(Delta) remained in most patients.