Unilateral Recession with Anterior Transposition of the Inferior Oblique Muscle for Correction of Hypertropia in Primary Position

Purpose: to evaluate the correction of hypertropia (HT) in primary position (PP) with unilateral inferior oblique (10) recession with anterior transposition (AT). Materials and Methods: 10 patients with essential HT with marked unilateral 10 overaction, who underwent unilateral recession with 10AT, were prospectively evaluated in order to observe the correction of the HT in PP. The 10 was re-inserted close to the lateral extremity of the inferior rectus muscles insertion, with only one suture. Results: the mean absolute correction was 18.1^Δ (82.3%), directly proportional to the size of the preoperative HT. Nine patients ended with residual deviation, smaller or equal to 6^Δ. Four patients presented pseudo-underaction (-2) of the operated 10, defined as a limitation of elevation, caused by the anti-elevator effect of the transposed muscle, which did not change with time.

Conclusion: unilateral 10 recession with AT is a good technique for correction of large hypertropia associated with marked unilateral 10 overaction.