Anterior transposition of the inferior oblique muscle for a snapped inferior rectus muscle following functional endoscopic sinus surgery.

A 55-year-old woman was referred with a 4-month history of diplopia following functional endoscopic ethmoidectomy for chronic sinusitis. She had right hypertropia of 14 prism diopters in the primary position that increased to 30 prism diopters in down gaze. Her right eye showed a moderate limitation of motion in down gaze. Orbital imaging demonstrated a snapped right inferior rectus muscle. The inferior oblique muscle was transposed as an initial treatment for the snapped inferior rectus muscle. After surgery, the patient was orthophoric and obtained fusion in the primary position.