Dysthyroid optic neuropathy improved markedly by plasmapheresis and steroid pulse therapy

A 56-year-old male patient suffering from hyperthyroidism had been treated with antithyroid drug and his thyroid function turned to euthyroid. However, he suffered from visual disturbance with his visual acuity of 0.01 and exophthalmus, which were diagnosed as dysthyroid optic neuropathy (DON). Post orbital injection of corticosteroid and oral administration of prednisolone up to 100mg at maximum per day were not effective. Therefore, he was treated with 2 courses of plasmapheresis (4 times/2 weeks each) and corticosteroid pulse therapy with drip infusion of 3, 000mg/3 days of methylprednisolone. His visual acuity improved up to 0.8 and exophthalmus was reduced with a disappearance of extraocular muscle enlargement on CT. Serologically, anti-TSH receptor antibody decreased to 10% from 64.5%, and serum IgG levels increased to 720mg/dl from 420mg/dl. A ratio of OKT4/OKT8 improved to 3.0 from 0.8. These results would indicate that the observed disappearance of extraocular muscle enlargement and the improvement of visual acuity could reffer to the normalization of his immunological disorders by plasmapheresis and steroid pulse therapy.