Combined oblique muscle surgery in bilateral trochlear paralysis

Fifteen patients with bilateral trochlear paresis underwent oblique muscle surgery. In 12 cases, a superior oblique tuck and inferior oblique recession were performed uni- or bilaterally. In 3 cases, a superior oblique muscle tuck was sufficient. Excyclotropia and vertical deviations in adduction, primary position and abduction were alleviated by surgery in most cases. The upper and lower limits of the field of single binocular vision were on average 15 degrees in the upward-gaze and 25 degrees in the downward-gaze. The presence of postoperative Brown syndrome was rarely disturbing to the patient. Postoperatively, the effects of surgery decreased only slightly over time. We found that in cases of bilateral superior oblique palsy, a tuck in one or both superior oblique muscles sufficed only when the excyclotropia in the primary position did not exceed 15 degrees, when the vertical deviation in adduction did not exceed 3 degrees and when the V-pattern was minimal. We found that uni- or bilateral surgery on both superior and inferior oblique muscles could successfully alleviate excyclotropia of more than 20 degrees with a vertical deviation in the primary position of more than 5 degrees.