Surgical treatment of compensatory head position in congenital nystagmus.

Records of 32 patients with congenital nystagmus who underwent surgery for a significant head turn were reviewed to assess the effectiveness of current surgical approaches. Eighteen patients (Group I) had single binocular vision and had bilateral recess/resect procedures either according to Parks' 5-6-7-8 scheme (nine patients) or "augmented" from 10% to 40% for large head turns (nine patients). Fourteen (78%) had a reduction of the turn to 15 degrees or less, six (33%) being 5 degrees or less. One was overcorrected . Fourteen patients had a heterotropia in addition to head turn. Seven (Group II) had bilateral surgery to attempt to correct the head turn and reduce the tropia to less than 10 prism diopters. In three cases (43%) there was both successful treatment of the tropia and reduction of the turn to 15 degrees or less. The tropia was successfully treated in six patients (86%). In seven patients (Group III) monocular recess/resect surgery was done to attempt to correct both abnormalities. In four (57%) the turn was reduced to 15 degrees or less with successful treatment of the tropia at the same time. Five (71%) had a tropia of less than or equal to 10 diopters postoperatively. Overall, the head turns were reduced to 15 degrees or less in 23 (72%) of the 32 patients including 11 (35%) with 5 degrees or less residual turn. Three (9%) were overcorrected at least 10 degrees. The frequency of undercorrections indicates that larger amounts of surgery have to be done, especially for large turns, although ductions will be limited in some gaze positions, at times significantly, to achieve this goal.