Brown's syndrome. A longitudinal long-term study of spontaneous course.

The prognosis for spontaneous improvement of Brown's syndrome has not yet been clarified. The present longitudinal long-term study comprised 10 patients with idiopathic Brown's syndrome arising or noticed during the first or second year of life. They were followed for an average of 13 years during which each had a mean of 9 examinations. Spontaneous improvement occurred in 9 of the patients, 3 of whom were cured, obtaining normal motility. All three cases had initially been permanent and monolateral, with initially mild, moderate, and severe restriction, respectively. In the remaining 6 patients who changed for the better, the spontaneous improvement consisted of a reduction of the initial hypotropia and the initial depression of the adducted eye. When the patients were last seen, the sensorial state of binocular vision demonstrated in 4 of the 10 normal binocularity, in 2 binocularity corresponding to microstrabismus, and in 4 alternating suppression.