[Nishida Extraocular Muscle Transposition Surgery for Abducens Nerve Palsy]

Surgical treatment of abducens nerve palsy depends on the remaining function of the lateral rectus muscle. Vertical rectus transposition surgery is indicated if the attempted maximal abduction effort does not rotate the eye beyond the midline. After the first description more than 100 years ago, a variety of muscle transposition modifications have been suggested. Nishida's minimally-invasive adaptation has attracted a great deal of attention in recent years.

Retrospective case series of four patients with abducens nerve palsy who were treated with Nishida muscle transposition surgery. Patients' characteristics with special emphasis on comparison between pre- and postoperative angle of deviation and ocular motility are reported.

Four patients (2 females, 2 males) were included in this study. Unilateral transposition surgery was performed in a 7-year-old girl and a 37-year-old woman with a left abducens nerve palsy. In a 56-year-old male with a left sixth nerve palsy and in an 82-year-old male with a right sixth nerve palsy the transposition maneuver was combined with a recession of the medial rectus muscle in the same eye. In all patients, ocular motility was improved and the angle of deviation was reduced.

Transposition of vertical rectus muscles is well established in the surgical treatment of abducens nerve palsy. Nishida's adaptation is a safe, effective and minimally-invasive treatment option. This vessel-sparing technique also allows for equilateral weakening of the medial rectus muscle.