Late results of superior oblique muscle tenotomy in true Brown's syndrome.

We re-assessed nine patients (aged 2 to 28 years) in whom true Brown's syndrome had been diagnosed and superior oblique muscle tenotomy performed. The postoperative period ranged from three to 12 years. The final results were divided into three groups: (1) Patients with partial residual Brown's syndrome postoperatively who gradually improved spontaneously over several years, with one exception. (2) Patients who had minimal or moderate superior oblique muscle paresis, secondary overaction of the homolateral inferior oblique muscle, and excellent binocular single vision postoperatively who improved spontaneously. In Groups 1 and 2, the study showed that the long-term results are better than those immediately after surgery, and the surgeon should not be too hasty in reoperating. (3) Patients with marked superior oblique muscle paresis and secondary homolateral inferior oblique muscle overaction postoperatively did not improve spontaneously and required a weakening procedure on the homolateral inferior oblique muscle.