Reduction of ocular muscle torque by splitting of the rectus muscle II: Technique and results

Abstract

Aim: To present the results of a new technique that the authors have developed to weaken the extraocular muscles. The biomechanics of this technique, which is termed ''Y-split recession,'' are given in the companion paper. Methods: A retrospective study, testing the effects of a new surgical technique on strabismus, nystagmus, and visual acuity. 228 patients (aged 6.8 (SD 6.0) years) with variable angle strabismus and nystagmus were treated by splitting and detaching two rectus muscles, and re-attaching the two halves at an angle of about 65˚to each other. Subjects were examined with the usual orthoptic tests immediately after the operation, and up to 96 months later. Results: The operation reduced the strabismus, eliminated or weakened the nystagmus in primary position, and improved binocular vision and the development of visual acuity. Only minor side effects were observed. Conclusions: The Y-split recession can be used to reduce the torque for extraocular rectus muscles, and provides an alternative to ''Cüppers Fadenoperation,'' recession, and similar procedures.

A comparison of two different techniques for oculomotor torque reduction

“…We used the following parameters: r a = 9.0 ± 0.7 mm, range 7.9–10.8 mm; r b = 8.0 ± 0.7 mm, range 6.6–10.5 mm. A detailed description of the surgical technique has been presented previously (Hoerantner et al. 2004).…”

“…Details of a simplified mathematical model describing the underlying biomechanics have been presented previously (Haslwanter et al. 2004), as have the corresponding surgical aspects (Hoerantner et al. 2004).…”

“…It involves Y‐splitting an extraocular muscle into two halves and reattaching the two halves at an angle to each other, by which the effective lever arm of this muscle can be significantly reduced (Castanera 1989; Roggenkamper 1989; Priglinger & Hametner 1994; Haslwanter et al. 2004; Hoerantner et al. 2004).…”

Reduction of ocular muscle power by splitting of the rectus muscle I: Biomechanics

“…Surgical procedures and additional diagrams and details are presented in the accompanying article. 31 A view from above shows that both muscle parts slide to the side, thereby reducing the effective lever arm (fig 5B, broken line). This mechanism is effective over the full oculomotor range (fig 5B).…”

Comparative study of Y-split recession versus bilateral medial rectus recession for surgical management of infantile esotropia

“…In the Y-split recession of MR technique, T reduction is caused by shortening of the effective r of the muscle. The muscle is split along 15 mm, and both ends are reattached separately, offering the advantage that the r of the muscle (and thereby the rotating T) is reduced, without any pull in the radial direction 17,18…”