Role of rectus muscle enlargement in clinical profile of dysthyroid ophthalmopathy.

Using logistic regression analysis, a correlation between enlargement patterns of the 4 rectus muscles and the occurrence of a variety of dysthyroid ophthalmopathy-associated ocular symptoms were analyzed in 698 eyes of 349 patients with this disorder. The condition of each rectus muscle was evaluated by computed tomography, and the various ocular symptoms were classified according to the Inoue classification system. The enlargement pattern, particularly when involving the inferior and medial recti, was found to have a strong statistical correlation with the occurrence of individual ocular symptoms. Additionally, the probabilities of the occurrence of most of the ocular symptoms were generally greater in those eyes with 2-, 3- or 4-muscle enlargement patterns than in those eyes with one or no enlarged rectus muscle.