Superior oblique palsy: a complication of endoscopic sinus surgery.

A 34-year-old woman with chronic sinusitis and nasal polyps was treated with bilateral pansinusotomy. Postoperatively, she had a unilateral superior oblique paresis. We suspect that superior oblique damage occurred without involvement of the medial rectus because of inadvertent entry of the endoscopic probe through the superior lamina into the left orbit.