Extraocular muscle injury during endoscopic sinus surgery: a series of 10 cases at a single center

Extraocular muscle (EOM) injury is a rare but serious complication of endoscopic sinus surgery (ESS). The aim of this study is to describe the clinical characteristics and course of EOM injury occurring during ESS.

Retrospective case series.

Medical records and CT images of patients who suffered from EOM injury after ESS between 2006 and 2012 were retrospectively reviewed. Patient demographics, endoscopic anatomy, type of surgery (primary or revision), predisposing risk factors, site and extent of injury on CT imaging, and associated complications were evaluated. In addition, data regarding ophthalmologic management and clinical outcomes were collected.

Ten patients with EOM injuries after ESS were included in this study. One patient was undergoing revision ESS. All patients sustained medial rectus muscle injury and one patient suffered concurrent ipsilateral inferior rectus muscle injury. A microdebrider was used in nine cases. Right-sided injury (90% of patients) was more prevalent than left-sided injury, and 70% of injured medial rectus muscles were completely transected. After subsequent strabismus surgery, 8/9 patients regained binocular single vision in primary gaze despite residual diplopia in some gaze positions.

Although proper ophthalmologic surgery after EOM injury may improve deviation in the primary gaze position, none of the patients regained normal EOM movement. Therefore, prevention of this complication through adequate surgical technique and precautions is important.