Evaluation of Surgical Strategy Based on the Intraoperative Superior Oblique Tendon Traction Test

PURPOSE To clarify the efficacy of a surgical strategy based on the superior oblique tendon traction test. METHODS A retrospective chart review was performed between January 2002 and June 2015. During that period, a single inferior oblique muscle (IO) myectomy and a combined IO myectomy and superior oblique muscle (SO) tuck procedure were performed based on SO tendon looseness as revealed by a traction test. The surgical effects of both procedures and the number of operations were analyzed. RESULTS Sixty-five cases were retrieved. Seventy-four surgeries were required. The IO myectomy and simultaneous groups included 48 and 17 cases, respectively. Pre-operative vertical deviation was significantly lower in the IO myectomy (11.8 prism diopters) than in the simultaneous (27.2 prism diopters; Mann-Whitney U-test, P < 0.001) group. The mean induced changes were 9.4 prism diopters and 21.6 prism diopters in the IO myectomy and simultaneous groups, respectively, and the postoperative vertical deviation was not significantly different. On average, 1.13 and 1.18 surgeries per patient were performed in the IO myectomy and simultaneous groups, respectively. CONCLUSION The simultaneous surgery of inferior oblique myectomy and superior oblique tuck is safe and effective for treating large angle of congenital/idiopathic superior oblique palsy with a lax superior oblique tendon, as determined by the traction test.