[Anterior transposition or myectomy of the inferior oblique muscle in vertical deviation--long-term results].

Anterior transposition of the inferior oblique muscle (ATIO) and myectomy of the inferior oblique muscle (MIO) are favorite methods for surgical correction of dissociated vertical deviation (DVD), including patients with simultaneous inferior oblique muscle overaction (IOOA). In our comparative, randomized study we evaluated whether anterior transposition improves the surgical outcome compared to myectomy of the inferior oblique muscle. We included 82 eyes of 46 patients, 44 eyes treated with ATIO and 38 treated with MIO. We observed the size of the preoperative and final DVD, grade of the preoperative and final IOOA, rates of reoperation, and complications. We found out that ATIO is an effective surgical approach in the treatment of DVD and it can be used in patients with or without IOOA. We found no statistically significant difference in postoperative outcomes between anterior transposition and myectomy of the inferior oblique muscle. Despite of it, we prefer unilateral ATIO to manage IOOA for its minor incidence of secondary hyperfunction of contralateral inferior oblique muscle.