Superior oblique luxation and trochlear luxation as new concepts in superior oblique muscle weakening surgery.

Purpose: We used superior oblique luxation and trochlear luxation as new surgical procedures to treat acquired Brown's syndrome and superior oblique muscle overaction.
Methods: We studied nine patients (11 eyes) who underwent trochlear surgery between 1988 and 1993. Four patients had acquired Brown's syndrome and five had superior oblique muscle overaction. In five patients (six eyes) the trochlea was incised to luxate the superior oblique tendon out of the trochlea. In four patients (five eyes) the trochlea was luxated out of its fossa via a periosteal approach without opening the trochlea itself.
Results: The mean follow-up was 18 months (range, nine to 33 months). Postoperatively, eight patients showed subjective and objective improvement. One patient with painful traumatic acquired Brown's syndrome had no objective improvement but obtained relief of pain.
Conclusions: These new techniques are a successful alternative in the treatment of acquired Brown's syndrome and superior oblique muscle overaction.