[Rectus muscle transposition for the treatment of complex ocular motility disorders]

Transposition techniques alter the muscle paths thereby creating new directions of muscle force. Extraocular muscle transposition procedures have been used to treat abducens palsy, Duane's retraction syndrome, double-elevator palsy and other complex ocular motility abnormalities. The purpose of this study was to evaluate the surgical and functional results of rectus muscle transposition in patients with different aetiologies of severe ocular motility deficits.

Between 1992 and 2008 rectus muscle transposition surgery has been performed on 31 patients. In this retrospective case series one patient with an abducens nerve palsy is presented as an example. In addition, six patients with motility disorders of different aetiologies who had transposition manoeuvers were evaluated. Preoperative, surgical and postoperative data are reported.

Rectus muscle transposition has been performed because of severe functional loss of the lateral rectus muscle, the superior rectus muscle or the medial rectus muscle as well as in myopic strabismus fixus. One of the patients had traumatic sixth nerve palsy. The underlying pathology in patients who had superior transposition of the horizontal rectus muscles were double-elevator palsy, congenital oculomotor nerve palsy and hypotropia caused by sphenoid wing hypoplasia. A nasal transposition of the vertical rectus muscles was performed in traumatic and tumour-associated muscle loss of the medial rectus muscle. The large preoperative deviations were markedly reduced postoperatively and even ocular motility partially improved.

Transposition surgery seems to be a suitable procedure for the treatment of complex ocular motility disorders. In cases of a complete lack of function of an extraocular muscle or in complex, uncommon conditions, which are difficult to treat with any other surgery, muscle transposition seems to be an effective procedure.