Disc-foveal angle and ocular counterrolling as a key in its interpretation

Superior oblique tendon thinning as a surgical treatment for Brown syndrome

PURPOSE

To evaluate the results of a superior oblique thinning technique for the treatment of congenital Brown syndrome.

METHODS

The medical records of consecutive patients at a single institution who were diagnosed with congenital Brown syndrome and underwent superior oblique thinning were retrospectively reviewed. In all cases, the prism cover test was used to assess ocular alignment. Standardized nine-gaze photographs were used to evaluate ocular rotations. Ocular torsion was measured using fundus retinography. Intraoperatively, all patients showed a positive forced duction test for elevation from adduction that became negative after a strongly maintained traction test maneuver.

RESULTS

A total of 21 eyes of 20 consecutive patients (mean age, 5.8 ± 2.5 years) were included. Preoperatively, 16 patients were orthotropic in primary position; 4, hypotropic. Postoperatively, all patients were orthotropic in primary position. Limitation of elevation in adduction improved from -3.4 ± -0.6 (range, -2 to -4) to 0.6 ± 1 (range, 0 to -3; P < 0.01). Fundus retinography showed >1° change in ocular torsion after surgery in 3 of 6 patients (P > 0.5). Superior oblique underaction or hypertropia did not occur. No superior oblique palsy appeared in any patient. There were no changes beyond 3 months postoperatively except for 1 patient who relapsed 9 months after surgery and 1 patient who improved after 4 years.

CONCLUSIONS

Superior oblique thinning is effective in improving elevation in adduction and hypotropia in primary position in patients with Brown syndrome associated with a thickened superior oblique tendon.