Graded versus ungraded inferior oblique anterior transposition in patients with asymmetric dissociated vertical deviation

Abstract

To report the surgical outcomes of graded versus ungraded inferior oblique anterior transposition (IOAT) in treatment of patients with asymmetric dissociated vertical deviation (DVD) and bilateral inferior oblique overaction (IOOA). A total of 74 eyes of 37 patients with asymmetric DVD (interocular difference of ≥5Δ) and bilateral IOOA of > +1 were included in this randomized clinical trial. In the ungraded group (n=18), both inferior oblique muscles were sutured at the inferior rectus level; in the graded group (n=19), the inferior oblique muscles of eyes with more DVD were sutured at the level of the inferior rectus and inferior oblique muscles of eyes with less DVD were sutured 2mm posterior to the level of the inferior rectus muscle. DVD was significantly reduced in each group (P<0.001 for both). Although the postoperative mean difference of asymmetry of DVD was less in the ungraded group compared to the graded group (1.2±1.9 vs 3.2±1.2 [P=0.001]), the absolute amounts of reduction of DVD asymmetry were similar (4.3±2.3 vs 4.4±3.1 [P=0.78]). IOOA and V patterns were also reduced postoperatively. Each method of IOAT was effective in reducing DVD, asymmetry, IOOA, and V patterns.