Surgical results of patients with A-pattern horizontal strabismus.

PURPOSE: To investigate the surgical results of patients having horizontal strabismus with A-pattern associated with superior oblique overaction (SOOA).

METHODS: Twenty patients with horizontal strabismus (12 exotropia [XT] and 8 esotropia [ET] with no previous strabismus surgery) with SOOA-associated A-pattern were analyzed retrospectively. Motor success was defined as a horizontal deviation of 8 prism diopters (PD) or less, 6 PD or less of vertical deviation in all gazes, and no greater than 8 PD of A-pattern. Stereoacuity was measured using the Titmus test (Stereo Optical, Chicago, IL).

RESULTS: Sixty percent of patients had successful results at the final examination. No significant difference was found between the XT and ET patients in preoperative and postoperative horizontal deviations in the primary position, A-pattern collapse, or success rate (P >.05). Four patients had an induced postoperative vertical deviation. Among eight patients without stereoacuity preoperatively, four showed an average of 910 seconds of arc (40 to 3000 seconds of arc) after surgery.

CONCLUSION: Simultaneous surgery on the horizontal and SO muscles in patients with horizontal strabismus with SOOA-associated A-pattern can achieve a relatively high surgical success rate and restore binocular function.