effect of treatment of Grave's disease on the course of ophthalmopathy

ABSTRACT

The incidence and progression of ophthalmopathy were compared retrospectively in 150 patients with Graves' disease treated with either radio-active iodine [131 I, N = 50], antithyroid drug [N=50]. None of the patients received prior treatment for hyperthyroidism. The severity of ophthalmopathy at presentation, as analyzed according to the modified NOSPECS classification and the thyroid function were similar in the three treatment groups. Six Patients had ophthalmopathy at about eighteen months before the development of biochemical hyperthyroidism [range 3 to 24 months]. For patients with ocular signs at presentation, the incidence of progression of ophthalmopathy was similar with each form of treatment. As a group, all forms of treatment resulted in improvement of ophthalmopathy with the control of hyperthyroidism. Forty six patients with no eye sign at presentation developed post-treatment ophthalmopathy. 131I and surgery were associated with more severe eye disease [NOSPECS Class 4-6] although the incidence of post-treatment ophthalmopathy was lower than with antithyroid drug treatment [2 percent versus 7 percent respectively]. Among the patients characteristics, male sex, older age [>35 ys] and lower initial T4 levels were found to be correlated with a higher chance of developing severe post-treatment ophthalmopathy. Furthermore the progression or development of ophthalmopathy could occur equally during hyper, hypo-, or euthyroid state. We conclude that the incidence and the degree of progression of ophthalmopathy in patients who already had exophthalmos before treatment were not influenced by the form of therapy for thyrotoxicosis, but 131I treatment and surgery were associated with the development of more severe post treatment ophthalmopathy compared to antithyroid drug treatment