Asymmetric inferior oblique anterior transposition for incomitant asymmetric dissociated vertical deviation

Abstract

Background Inferior oblique anterior transposition (IOAT) is indicated in patients with incomitant dissociated vertical deviation (DVD) larger in adduction. In general, bilateral surgery is recommended in patients with DVD unless there is deep monocular amblyopia. The purpose of this study is to evaluate the results of asymmetric IOAT in patients with asymmetric incomitant DVD larger in adduction. Methods Retrospective chart review of the records of all patients with incomitant asymmetric DVD associated with inferior oblique (IO) overaction who underwent asymmetric IO weakening procedure. In all patients, the eye with more DVD in adduction underwent IOAT to the temporal corner of the insertion of the inferior rectus (IR) muscle, and the eye with less DVD underwent IOAT to a position 3–4 mm posterior to the insertion of the IR. No other muscles were operated simultaneously. No patient had previous surgery on any cyclovertical extracular muscle. Results Fourteen patients were included. Mean age at surgery was 10.3 ± 8.8 years (range 4–33). Primary position DVD preoperatively was 18 ± 2 PD in the eye with the larger DVD compared to 1.1 ± 1.0 PD postoperatively (p <0.0001). DVD asymmetry between the lateral gaze with the largest DVD and the lateral gaze with the smallest DVD was 9.8 ± 3.1 PD (range 5–14 PD) preoperatively vs 1.1 ± 1.0 PD (range 0–2 PD), (p < 0.0001). Ten patients had preoperative V-pattern >10 PD (24.7 ± 8.7 PD, range 12–50 PD) preoperatively vs no patients postoperatively (mean V-pattern 4.4 ± 2.0 PD), (p <0.0001). Postoperative follow up was 1.6 ± 0.7 years (range 1–3 years). Conclusion In patients with asymmetric incomitant DVD, asymmetric IOAT improves lateral incomitance without increasing the risk of antielevation, limitation in upgaze rotation, or hypertropia, or worsening the DVD in the eye with less deviation preoperatively.

Unilateral Inferior Oblique Anterior Transposition for Asymmetric Dissociated Vertical Deviation with Unilateral Inferior Oblique Over-action

“…Symmetric DVD was always treated with symmetric surgery, whereas asymmetric DVD or IOOA were more challenging. Pineles et al [9] used asymmetric IOAT to treat 14 patients with incomitant asymmetric DVD and resulted in improvements of incomitant DVD, V-pattern and IOOA. Snir et al [8] suggested 5 bilateral IOAT with monocular-graded inferior oblique resection for asymmetric DVD with IOOA.…”

“…Most clinicians suggested that binocular DVD should be treated with binocular surgery, especially for symmetric DVD [5][6]. However, treatment decisions for asymmetric DVD were more complex, asymmetric [8][9] or unilateral [4] surgery may be considered. Unilateral IOAT has been reported satisfied outcomes in some studies despite some possible adverse outcomes, such as hypotropia and antielevation syndrome [2 , 4 ,10].…”

Unilateral Inferior Oblique Anterior Transposition for Markedly Asymmetric Dissociated Vertical Deviation with Unilateral Inferior Oblique Over-action

“…The management of DVD is challenging for strabismus surgeons. Multiple approaches have been proposed for the treatment of DVD, but there is no agreement among surgeons regarding the best practice [7]However, when DVD coexisted with IOOA, IOAT is preferred by most clinicians as it reduces the IOOA while simultaneously restricting the superior floating phenomenon of DVD [2,3,4,8,11,12]. Full IOAT includes the posterior fibers with J deformity that form a neurofibrovascular bundle.…”

Unilateral Inferior Oblique Anterior Transposition for Markedly Asymmetric Dissociated Vertical Deviation with Unilateral Inferior Oblique Over-action

“…Most clinicians suggested that binocular DVD should be treated with binocular surgery, especially for symmetric DVD [3,5,7]. However, treatment decisions are more complex in asymmetric DVD, in which bilateral asymmetric [8,9,10] or unilateral [4] surgery may be considered. Due to the possibility of adverse outcomes, such as hypotropia and contralateral DVD, bilateral surgery was more accepted by clinicians.…”

“…Multiple approaches have been proposed for the treatment of DVD, but there is no agreement among surgeons regarding the best practice[7]. However, when DVD coexisted with IOOA, IOAT is preferred by most clinicians as it reduces the IOOA while simultaneously restricting the superior floating phenomenon of DVD[2,3,4,8,11,12]. Full IOAT includes the posterior fibers with J deformity that form a neurofibrovascular bundle.…”