A 38-year-old woman was referred to our clinic in September, 1991 because of diplopia, limitation of right eyeball movement, and right eye lid edema. In August, 1990, an ophthalmologist at our hospital had not detected any organic abnormalities except enlargement of the bilateral medial rectus muscles examined by MRI (Fig.2). The patient was euthyroid and had absolutely no symptoms suggestive of hyperthyroidism. Thereafter, she had been treated with prednisolone (10-20 mg per day).
Physical examination revealed that her height was 162 cm and weight was 45.2 kg. Her blood pressure was 146/82 mmHg, and pulse rate 72/min. with regular rhythm. Graefe's sign and lid retraction were observed at the right eye. Disturbance of right eyeball movement was observed in right lateral view (Fig.3). However, the proptosis was 16 mm for both eyes with a base line of 102 mm. The thyroid was not palpable. No abnormality of the heart, chest or abdomen was detected. The deep tendon reflexes were normal.
Laboratory studies revealed slight leukocytosis due to the effect of prednisolone treatment, and normal urinalysis values (data not shown). Biochemical tests disclosed hypercholesterolemia and low level of creatine kinase (data not shown). Thyroid function studies revealed euthyroidism and no thyroid abnormalities except TSAb, which showed activity of 240% (Table 1). Thus, her illness was diagnosed as euthyroid Graves' disease.
The symptoms were kept under good control with prednisolone(5-20mg/day). In November, 1993, however, the right eye symptoms intensified and edema of the left eye lid was noted. Therefore, we increased the dose of prednisolone to 60mg/day and applied external radiotherapy to the bilateral extraocular muscle for 2 weeks (total 20 Gy) in December, 1993. The changes in the patient's TSAb activities during the course of treatment are shown in Figure 4. The TSAb activities changed in parallel with the severity of her eye symptoms.