Clinical characteristics and surgical management of congenital absence of the superior oblique tendon.

We reviewed clinical characteristics and surgical results of nine patients with surgically proved congenital absence of the superior oblique tendon. The following factors indicate absence of the tendon in the setting of superior oblique palsy: (1) an associated horizontal deviation, (2) amblyopia, (3) a large hypertropia in primary position, (4) spread of comitance, and (5) pseudo-overaction of the contralateral superior oblique muscle. The nine patients required a total of 19 operations to correct their vertical and horizontal deviations. Surgical management was based on the preoperative action of the inferior oblique muscle, the amount of hypertropia in primary position, and intraoperative forced ductions. After their operations, eight of nine patients had improvement in or abatement of their symptoms, and seven of seven with preoperative head tilts had improvement of their head position.