ABSTRACT
ABSTRACT: Purpose: Anterior transposition of the inferior oblique muscle (ATIO) and myectomy of the inferior oblique muscle (MIO) are a popular surgical methods for dissociated vertical deviation (DVD), also in patients with coexisting inferior oblique muscle overaction (IOOA). We evaluated whether anterior transposition improves the outcome compared with myectomy of the inferior oblique muscle. Methods: We undertook a prospective, comparative, randomized evaluation of ATIO and MIO, in patients with DVD of at least 5 PD in one eye. We included 82 eyes of 46 patients, 44 eyes treated with ATIO and 38 treated with MIO. We recorded the size of the preoperative and final DVD, grade of the preoperative and final IOOA, rates of reoperation, and complications. Mean followup was 29.6 months in the ATIO group and 36.5 months in the MIO group, with a minimum of 12 months for all cases. Results: The mean preoperative and postoperative DVD was 13 PD and 4 PD in the ATIO group, respectively. This compared with 15 PD and 3 PD, respectively, in the MIO group, representing no statistically significant difference in outcome. The presence or absence of IOOA did not influence the result of ATIO and MIO for both groups. No significant complications of surgery occurred in either group. Conclusions: ATIO is an effective treatment for DVD and can be used to treat DVD in patients with or without IOOA, with no adverse effects. Our study revealed no statistically significant difference in outcome between anterior transpositon and myectomy of the inferior oblique muscle.
