Assessment of combined transposition of the inferior oblique muscle belly without disinsertion and contralateral inferior oblique recession for treating asymmetric inferior oblique muscle overaction (IOOA).

Abstract

Background: This study aimed to investigate the efficacy of inferior oblique belly transposition (IOBT) combined with contralateral inferior oblique recession in treating bilateral asymmetric inferior oblique overaction (IOOA).

Methods: A retrospective study was conducted on 23 patients with asymmetric IOOA. IOBT was performed on the less affected eye of the patient, while the contralateral inferior oblique recession was conducted on the more affected eye. Pre- and post-operative changes in the vertical deviation, V-value, fovea-disc angle (FDA), and inferior oblique muscle function were compared. Follow-up duration ranged from 3 to 8 months.

Results: The V-pattern was corrected in all cases, and the V-value improved from 14.57 ± 4.50 preoperatively to 4.09 ± 2.17 postoperatively (t = 12.640, P < 0.001). The preoperative vertical deviation (5 m) significantly decreased from 8.04 ± 3.08 to 1.57 ± 1.90 postoperatively (t = 8.713, P < 0.001). Similarly, the lesser side FDA reduced from 11.39° ± 2.39° before surgery to 6.62° ± 1.11° after surgery (t = 11.132, P < 0.001). On the greater side, the FDA also showed significant improvement, reducing from 14.39° ± 2.45° preoperatively to 7.43° ± 1.23° postoperatively (t = 11.231, P < 0.001). No patients experienced anti-elevation syndrome (AES) or complications such as reverse head tilt postoperatively.

Conclusion: IOBT combined with contralateral inferior oblique recession could effectively treat asymmetric IOOA in patients with ocular asymmetry.