Objective: To evaluate the effect of surgery to treat anti-elevation syndrome following anterior transposition of inferior oblique muscle (ATIO).
Methods: We retrospectively studied six cases of anti-elevation syndrome that had surgical history of anteriorization of inferior oblique muscle. We disinserted the inferior oblique from the transposed insertion and simultaneously weakened the contralateral inferior oblique for three cases with severe limited supraduction. We anteriorized the contralateral inferior oblique muscle for other three cases with mild or moderate limitation. The patients were followed up more than 6 months.
Results: Six cases we aged from 5 to 22 years. Postoperatively, vertical deviation in primary position improved to less than 6 PD with no more abnormal head position. Three cases with severe limited supraduction showed great improvement. All patients showed no more over reaction of contralateral inferior oblique muscle. Three cases with previously DVD showed improved drift of contralateral eye. All patients were satisfied for the correction and no more surgery were done. The results persisted after six months follow up.
Conclusions: Disinserting the inferior oblique from the transposed insertion is an effective way to treat anti-elevation syndrome with severe limited supraduction. Unilateral anterization of inferior oblique should be avoided.