Development or progression of ophthalmopathy

Four hundred forty-three patients with Graves' hyperthyroidism were randomly assigned to receive radioiodine, radioiodine followed by a three-month course of prednisone, or methimazole for 18 months. Development or worsening of ophthalmopathy occurred more often in the radioiodine than in the methimazole group. Worsening of ophthalmopathy was prevented by the administration of prednisone.