[Eye muscle surgery in unilateral abducens palsy]

Preliminary Results of New Modification of Vertical Muscle Transposition to Enhance Abducting Force in Sixth Nerve Palsy

Introduction

Since 1907, multiple transposition procedures have been established for the treatment of abducens paralysis. The purpose of the study was to determine where the transposed muscle should be reattached in order to increase the tangential force necessary to improve abduction.

Methods

Retrospective case review of 12 consecutive patients with abducens paralysis who underwent transposition procedures between 2016 and 2019 was conducted. Vertical rectus muscles are transposed to the insertion of lateral rectus muscle; the temporal parts are joined and sutured to the sclera on top of the lateral rectus muscle in the middle of the insertion. The nasal parts are sutured to the sclera following the spiral of Tillaux. The muscle junction suture is placed 8 mm from the insertion, with the temporal parts of the vertical muscles bellies joined and sutured to the lateral rectus muscle. A full-tendon transposition was performed on 11 patients, a half-tendon transposition procedure on 1 patient. The minimum follow-up was 3 months.

Results

The mean preoperative deviation was ET of 37° (range: ET 24° to ET 51°). The mean preoperative abduction limitation was 5 mm from midline (range: 7 to 1 mm). The postoperative mean deviation was ET of 2° (range: 0° to ET 5°). The postoperative mean abduction improvement was 5 mm past midline (range: 2-6 mm). There were no complications or signs of anterior segment ischemia.

Conclusion

To achieve the maximal abductive force from the transposed muscles, we suggest that the vertical muscles be reattached as close as possible to the middle of the lateral rectus insertion.

Medial rectus recession is as effective as lateral rectus resection in divergence paralysis esotropia

OBJECTIVE

To propose medial rectus (MR) recession to be equally as effective as lateral rectus (LR) resection, which has heretofore been the preferred treatment for divergence paralysis esotropia (DPE).

METHODS

We examined a 17-year surgical experience comparing LR resection with MR recession in adults with DPE, defined as symptomatic distance esotropia (ET) at least double the asymptomatic ET of 10 or less prism diopters() at near.

RESULTS

Twenty-four patients with DPE underwent surgery. Six patients underwent bilateral LR resection and 2 underwent unilateral LR resection (group L), while 13 underwent bilateral MR recession and 3 underwent unilateral MR recession,with the target angle double the distance ET (group M). One of 8 patients in group L and 15 of 16 patients in group M underwent intra operative adjustable surgery under topical anesthesia. Mean (SD) preoperative central gaze ET measured 15.0 (7.7) Δ at distance and 4.1 (3.4) Δ at near in group L, but 10.4 (6.8) Δ at distance and 0.6 (1.7) Δ at near in group M (P=.15; distance, 0.003, near). Postoperatively, no patient in either group had symptomatic diplopia or convergence insufficiency in follow-up from 8.5 to 40 months. Twice the usual surgical dose of MR recession per prism diopter was required to achieve correction of the distance deviation in DPE as compared with that recommended for ET generally and also for LR resection in the same condition.

CONCLUSIONS

Recession of the MR provides binocular single vision in DPE without convergence insufficiency at near, and it is convenient for intraoperative adjustment under topical anesthesia.