Can Graves Ophthalmopathy be treated with radiation?
I have Graves' disease with bulging eyes. I have been taking steroids with some success initially but my eye problem appears to be worse. I am also suffering from the side effects of steroids. I heard that this type of eye problem could be treated with radiation. Can you provide me more information?
Li Liu, MD, OncoLink editorial assistant, responds:
Thank you for your interest and question.
Bulging eyes associated with Graves' disease (Graves' ophthalmopathy) is characterized by swelling (edema) and inflammation of the eye (extraocular muscles) and an increase in orbital connective tissue and fat. The edema is secondary to the increased water pressure due to protein secreted by fibroblasts. The inflammation is due to infiltration of the extraocular muscles and orbital connective tissue by lymphocytes and macrophages. The increase in the volume of tissue behind the eyes (retrobulbar) is responsible for most of the clinical manifestations of ophthalmopathy. Clinically evident ophthalmopathy occurs in about 50% of patients. Of them, 75% of eye signs appear within a year before or after the diagnosis of hyperthyroidism (Arch Intern Med 1988 Apr; 148(4): 788-94). Mild-to-moderate ophthalmopathy often improves spontaneously, and only simple measures are needed. For patients with severe ophthalmopathy, in particular impaired vision, high doses of steroids have been used with improvement seen in about two thirds of patients (Baillieres Clin Endocrinol Metab 1997 Oct; 11(3): 521-36).
The value of orbital irradiation has been established in clinical studies (Thyroid 1995 Jun; 5(3): 231-4), but it is still not widely accepted as the initial treatment of choice for patients with severe ophthalmopathy. Radiation helps ophthalmopathy by killing T lymphocytes to reduce inflammation behind the eyes. It is most often used in patients in whom steroids are contraindicated, poorly tolerated, or cannot be discontinued because of exacerbation of ophthalmopathy. Whether combined radiation and steroid therapy is more effective than either alone is controversial (J Clin Endocrinol Metab 1983 Jun; 56(6): 1139-44).
Orbital irradiation is most effective in reducing the inflammatory manifestations of ophthalmopathy, with little or no change in bulging eyes and muscle function. The usual dose is 20 Gy, administered in 10 doses of 2 Gy over two weeks. Orbital irradiation is contraindicated in diabetic patients, because of the risk of added retinal damage.
You should discuss your problems with your endocrinologist and perhaps get a consultation from a radiation oncologist.