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. .