Relationship between management of hyperthyroidism and course of the ophthalmopathy

The relationship between treatment for hyperthyroidism and course of Graves' ophthalmopathy (GO) has been and still is a matter of debate. Literature often presents conflicting data, due to several influencing factors, such as selection bias, nonrandomized and uncontrolled or retrospective features of many studies, nonstandardized evaluation of ocular changes. However, it seems clear that neither antithyroid drug treatment nor thyroidectomy affect the natural course of GO, while radioiodine therapy may cause, in about 15% of cases, GO progression. The latter is more likely in patients who smoke, have pre-existing GO and more severe hyperthyroidism, or whose post-radioiodine hypothyroidism is not promptly corrected by L-thyroxine. GO progression after radioiodine therapy can be prevented by concomitantly treating patients with glucocorticoids, thus making radioiodine therapy a safe procedure also in GO patients. The presence of GO should not, therefore, influence the choice of treatment for hyperthyroidism. Should antithyroid drug treatment or thyroidectomy be selected for patients with mild ophthalmopathy, no treatment for GO is necessary, while a short course of moderate doses of glucocorticoids is advised if radioiodine therapy is chosen. In patients with severe GO, treatment of hyperthyroidism and management of GO proceed independently of each other, and either definitive (radioiodine or thyroidectomy) or conservative (antithyroid drugs) treatment for hyperthyroidism can be selected while treating GO. The authors' preference goes to the former, because it depletes intrathyroidal autoreactive T lymphocytes and removes thyroid antigens, which are likely to be involved in the pathogenesis of autoimmune reactions of the ophthalmopathy.