The Clinical Phenotype of Thyroid-Associated Orbitopathy related to Underlying Thyroid Status

ABSTRACT

PURPOSE: Thyroid-Associated Orbitopathy (TAO) presents with highly variable clinical characteristics. We hypothesize that the underlying thyroid status predisposes a patient to different clinical characteristics of TAO. METHODS: We retrospectively studied the clinical data of 385 patients from the New York area who were referred to our clinic and diagnosed with TAO from Jan 1990 to Dec 2000. We divided the 385 patients into three groups Graves' hyperthyroid, euthyroid, and hypothyroid, and analyzed them statistically. RESULTS: Three hundred thirty-one (86%) patients were hyperthyroid, 25 (6.5%) were euthyroid, and 29 (7.5%) were hypothyroid. The average age of TAO presentation in each group was 46.7, 46.1, and 49.9 years, respectively. The female-male ratio in each group was 5.25, 3.17, 13.51, respectively (p>0.05). The average time from thyroid disease to TAO in the hyperthyroid and hypothyroid groups was 16.6 and 38 months, respectively (p<0.05). The hyperthyroid group had more proptosis (76.1 vs. 41.4%, p=0.0001<0.05) than the hypothyroid group. CONCLUSIONS: TAO has different clinical characteristics depending on thyroid status. The hyperthyroid group has a short disease interval and more severe clinical course of TAO than the hypothyroid group.