Muscle transposition procedure treats abducens palsy without tenotomy

This small, retrospective case series reports on the successful use of a new muscle transposition procedure to treat abducens palsy without performing tenotomy or splitting transposed muscles.

The authors performed this procedure in nine patients with esotropia resulting from abducens palsy whose eyes could not abduct beyond the midline.

All nine patients underwent unilateral muscle transposition, with six of them undergoing a medial rectus muscle recession combined with muscle transposition in the same eye.

To perform the muscle transposition procedure, the authors inserted a monofilament suture through the temporal margin of each vertical rectus muscle and into each inferotemporal or superotemporal sclera. The lateral margin of each vertical rectus muscle was then transposed superotemporally or inferotemporally and was sutured onto the sclera.

The surgical correction by muscle transposition alone ranged from 24 to 36 prism diopters, and by muscle transposition and recession of the medial rectus muscle from 50 to 62 prism diopters. The mean correction was 46.3 ± 13.1 prism diopters per eye. All paretic eyes could abduct beyond the midline. No major vertical ductional disturbances developed, and anterior segment ischemia did not occur in any patients.

The authors write that this procedure achieved the same corrective results as other popular procedures, is simple to perform because it requires only a suture from the muscle to sclera, and is less traumatic to the eye because tenotomy and splitting of the muscle are not required.

Also, the circulation in the transposed rectus muscles is affected less because each muscle suture is placed apart from the large vessels of the muscle and only one-third of the entire muscle width is ligated. Even when a medial rectus muscle recession is combined with the muscle transposition procedure, the circulation in the other the rectus muscles can be preserved.

They conclude that a study evaluating the surgical effects of the muscle transposition procedure with more patients and longer follow-up are warranted.