Adjustable suture technique for enhanced transposition surgery for extraocular muscles

Purpose: To evaluate the results of 2 methods of vertical rectus muscle transposition surgery for sixth (abducens) nerve palsy. Methods: Retrospective, comparative case series. Historically at our institution, transposed vertical rectus muscles were adjusted toward or attached at the adjacent corners of the lateral rectus muscle ("conventional transposition") before the development of a technique in which adjustable sutures are passed beneath the lateral rectus muscle to attach at its opposite corners ("crossed- adjustable transposition"). Comparative outcomes with these 2 techniques were analyzed in a consecutive series of sixth nerve palsy patients. Results: The change from preoperative to postoperative deviation at distance was 39.3^Δ ± 22.7^Δ in 23 conventional transposition cases and 48.5^Δ ± 27.8^Δ in 19 crossed-adjustable transposition cases, which demonstrated no statistically significant difference (p = 0.24, t-test). Simultaneous medial rectus weakening was needed less in the crossed-adjustable transposition group (37%) than in the conventional transposition group (83%), and this difference was statistically significant. (p = 0.004, Fisher exact test). Conclusions: Adjustable vertical rectus muscle transposition surgery for the management of chronic sixth nerve palsy, enhanced by passing the adjustable sutures beneath the lateral rectus muscle, requires simultaneous medial rectus muscle weakening less than half as often for satisfactory results.