Strabismus following endoscopic intranasal sinus surgery.

Two patients developed exotropia with limited medial rectus function following endoscopic intranasal ethmoid sinus surgery. In both patients, fractures occurred in the medial orbital wall. The first patient required horizontal rectus muscle surgery to regain ocular alignment. The second required no surgery, but was left with limited horizontal motility secondary to scarring at the fracture site. While endoscopic techniques improve the surgeon's view of sinus anatomy, they do not eliminate the risk of entering the orbit and causing ocular complications.