Simplification of the complex: Successful management of large-angle exodeviation after endoscopic sinus surgery

To report the clinical characteristics and successful management of large-angle exodeviation due to medial rectus muscle (MR) transection incurred during endoscopic sinus surgery (ESS).

The medical records of 5 consecutive inpatients with MR complete transection following ESS resulting in large-angle paralytic exodeviation between November 2014 and June 2021 were reviewed. The type of muscle injury, clinical characteristics, surgical procedure and dosage, and long-term outcomes were evaluated.

All 5 patients manifested exodeviations of 72 PD to >133 PD with no adduction capacity (graded -4); all of them had proven orbital trauma and complete MR transection with a ≥20 mm distal (globe attached) stump based on CT scans and/or MRI imaging. They underwent a supra-maximal recession (10-12 mm) of the lateral rectus and resection (10-15 mm) of the medial rectus on the affected eye. At least 1 year (1 to 5 years) following the corrective surgery, the patients still maintained orthophoria or had a small angle of exotropia (≤ 8 PD) in primary gaze with successful fusion, and 3 of them (Case 3, 4, and 5) exhibited a certain degree of stereopsis. In addition, appreciable adduction occurred (graded -1 to -3).

A supra-maximal recession/resection shows favorable outcomes in patients with proven complete transection MR with a ≥20 mm distal (globe attached) stump. It can help to achieve good ocular alignment and even yield improvements in adduction over time.