Brown's syndrome.

Brown's syndrome is a well-recognized clinical disorder of ocular motility manifesting most notably a restriction of active and passive elevation in adduction. The original name, "superior oblique tendon sheath syndrome," is no longer appropriate, since it has been shown that the tissue surrounding the anterior superior oblique tendon is blameless as a restrictive force. "True" and "simulated" as descriptive modifiers should also be discarded, as they relate to the disproven sheath concept. Brown's syndrome occurs as a congenital or acquired, constant or intermittent condition; the common link is restriction of free movement through the trochlea pulley mechanism. The various etiologic theories are reviewed and the spectrum of medical and surgical treatments are described and evaluated. Evidence suggests that subtypes of Brown's syndrome lie on a single continuum and that spontaneous resolution occurs in each group, probably more often than previously recognized. A simplified classification scheme is encouraged and possible future directions in Brown's syndrome research are introduced.