Clinical Manifestations of Inferior Oblique Overaction in Patients with Horizontal Strabismus

ABSTRACT

PURPOSE: To investigate the clinical manifestations of and the surgical success rates in patients with horizontal strabismus and inferior oblique overaction (IOOA). METHODS: The patients included in the present study had received myectomy for correction of IOOA and had at least 3 months of follow-up. The patients were divided into 2 groups; patients who received myectomy and surgery for horizontal strabismus simultaneously (combined group, 74 eyes of 49 patients) and patients who received myectomy only (myectomy group, 29 eyes of 24 patients). Chief complaints, head tilt, bilaterality of IOOA, ocular torsion, and the surgical success rates were analyzed. RESULTS: In the combined group, 51% of the chief complaints were horizontal deviation, and in the myectomy group 42% were upward deviation and 29% were head tilt. Objective head tilt was 29% in the combined group and 54% in the myectomy group and the difference was significant. There was no significant difference statistically in the success rate of myectomy. CONCLUSIONS: The frequency of symptoms associated with IOOA in the combined group was lower than in the myectomy group. Therefore, preoperative examination regarding IOOA should be carefully performed in patients who are planning a horizontal strabismus surgery because there was no difference in surgical success rate between the 2 groups, the association with horizontal strabismus may have no effect on the surgical results of IOOA.