Radioiodine & Ophthalmopathy
A 50-year-old man with Graves' disease and mild exophthalmos is being considered for ¹³¹I therapy. Which of the following statements regarding ¹³¹I therapy in this patient is most accurate?
Correct Answer — B
Radioiodine can worsen pre-existing Graves' ophthalmopathy by triggering an immune response — radiation-induced thyroid cell death releases thyroid antigens that may amplify the autoimmune attack on orbital fibroblasts (which share TSH receptor epitopes). In patients with active or at-risk eye disease, prophylactic corticosteroids should accompany ¹³¹I therapy. Post-treatment hypothyroidism must also be avoided, as it can independently worsen ophthalmopathy by elevating TSH (which stimulates TSH receptors in orbital tissue).
Key concept
¹³¹I and ophthalmopathy: use with caution; consider prophylactic steroids; avoid subsequent hypothyroidism (worsens eye disease).