Relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy.

To elucidate the relationships of orbital computed tomographic findings and activity scores to the prognosis of corticosteroid therapy in patients with Graves' ophthalmopathy, 22 cases were treated with corticosteroid. Orbital computed tomographic was performed before treatment and the maximal muscle areas of rectus muscle bellies were calculated from the coronal images. Activity scores were calculated according to the recommendations of an international ad hoc committee. The clinical severity of the eye disease was based on the NOSPECS classification. Observation of the effectiveness of treatment at 6 months allowed patients to be classified into good responders or poor responders. Twelve of 22 patients (54.5%) belonged to the good responders. The total muscle areas were less in good responders. Although the total muscle areas were significantly correlated with the activity scores, no difference in the activity scores was noted between these two groups. We concluded that although activity score seems to be a predictor of initial responsiveness to anti-inflammatory drugs, the maximal muscle area is a prognostic factor of corticosteroid therapy in patients with Graves' ophthalmopathy.