Surgical outcome of inferior oblique anteriorization in unilateral superior oblique palsy with large angle hypertropia

Abstract

Purpose The aim of this study was to assess the effect of unilateral inferior oblique (IO) anteriorization as a single muscle surgery for treatment of unilateral superior oblique palsy (SOP) with large angle hypertropia. Patients and methods This is a retrospective study that included 28 patients, for whom IO anteriorization was performed for treatment of ipsilateral SOP with large angle hypertropia more than or equal to 20 prism diopters (PD). The patients were evaluated preoperatively and 3 months postoperatively for the vertical deviation (VD) in primary position and in adduction. Residual hypertropia less than or equal to 6 PD in primary position postoperatively was considered a successful outcome, together with improvement of the abnormal head tilt. Results The mean age of the patients was 30.75±17.05 years. The mean preoperative VD in the primary position was 25.29±4.50 PD. It significantly decreased postoperatively to 5.54±5.25 PD (P<0.001). The mean preoperative VD in adduction was 30.57±7.89 PD and decreased postoperatively to 8.50±5.27 PD (P<0.001). The preoperative IO overaction grade was 2.61±0.99 and decreased postoperatively to 0.39±0.50 (P<0.001). Successful outcome was reported in 75% of the cases and improvement of head tilt occurred in 78% of the patients. Conclusion IO anteriorization could be a simple one muscle surgery to correct large angle VD associated with unilateral SOP with a favorable outcome.