Superior oblique tendon advancement: its success as single or combined muscle treatment for selected cases of unilateral superior oblique palsy

Purpose: To evaluate the efficacy of single or combined superior oblique tendon (SO) advancement for selected cases of unilateral superior oblique palsy (SOP). Methods: The medical records of 14 patients who underwent single or combined superior oblique tendon advancement in one institution from May 2017 to October 2018 were reviewed. All subjects with a diagnosis of unilateral SOP who underwent single or combined SO tendon advancement surgery were included. The goal of the surgery was to correct the hypertropia and head tilt. The single or combined SO tendon advancement surgery was selected based on the amount of hypertropia or head tilt and the Knapp classification of the SOP. The information recorded included pre- and postoperative deviation angle and ocular motility findings. The degree of upshoot in adduction was graded pre- and postoperatively. Results: Fourteen patients between the age of 3 and 52 years with unilateral superior oblique palsy were selected to undergo SO tendon advancement. Single SO tendon advancement was carried out in eight acquired Knapp class II or residual SOP patients. SO tendon advancement combined with contralateral inferior rectus recession was carried out in two acquired Knapp class II patients. SO tendon advancement combined with ipsilateral inferior oblique myectomy was carried out in four congenital Knapp class III patients. The changes in pre- and postoperative hypertropia at primary gaze in single SO tendon advancement patients were from 6.25 +/- 2.12 prism diopters to 0.86 +/- 1.46 prism diopters. The changes in degree of upshoot in adduction were from +1.86 to +0.21. Conclusions: SO tendon advancement worked well as single or combined muscle procedure to treat unilateral superior oblique palsy.