A new application of modified Nishida muscle transposition procedure for medial rectus muscle transection following endoscopic sinus surgery without tenotomy or splitting muscles.

The modified Nishida muscle transposition procedure, in which the one-third of the vertical rectus muscle bellies are sutured onto the sclera in the infero- and superotemporal quadrants without either tenotomy of the vertical rectus muscles or splitting of the vertical rectus muscle is an effective treatment for abducens nerve palsy. We report 2 cases of large-angle exotropia caused by medial rectus transection following the endoscopic sinus surgery treated using the modified Nishida procedure to transpose both vertical rectus muscles nasally, combined with lateral rectus muscle recession.