A new application of modified Nishida muscle transposition procedure for medial rectus muscle transection following endoscopic sinus surgery without tenotomy or splitting muscles

Incidence, Management, and Outcome of Pulled-in-Two Syndrome Associated With Strabismus Surgery

PURPOSE

To report the incidence and outcomes of pulled-in-two syndrome during strabismus surgery and investigate the clinical features and management of the disease.

METHODS

The medical records of patients who underwent strabismus surgery and developed pulled-in-two syndrome between July 2013 and October 2020 were reviewed retrospectively. The demographic characteristics, intraoperative details (including surgery type and management), and subsequent and final outcomes were extracted from the records.

RESULTS

Of the 11,824 strabismus surgeries during the study period, 4 cases of pulled-in-two syndrome were documented, accounting for an overall incidence of 0.034%. The average age of the patients with pulled-in-two syndrome was 61.75 ± 8.99 years. All 4 patients were women; 2 had abducens nerve palsy and the other 2 had myopic strabismus fixus. The inferior rectus muscle was involved in 1 patient and the medial rectus muscle was involved in 3 patients. All of the involved extraocular muscle was lost. One patient achieved orthotropia, and the others were undercorrected after the surgery.

CONCLUSIONS

Pulled-in-two syndrome is one of the rarest and most severe complications of strabismus surgery. Cranial nerve palsy, advanced age, prior surgery, thyroid-associated ophthalmopathy, and degenerative conditions of the extraocular muscle are risk factors for pulled-in-two syndrome. Therefore, the prevention of pulled-in-two syndrome in patients with these risk factors should be investigated further. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].

[Nishida Extraocular Muscle Transposition Surgery for Abducens Nerve Palsy]

BACKGROUND

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.