Graves Ophthalmopathy
A 35-year-old woman is diagnosed with Graves disease after 5 kg weight loss, palpitations, heat intolerance, and a diffuse goitre with a bruit. Thyroid-stimulating hormone is undetectable, free thyroxine 42 pmol/L, and thyrotropin receptor antibodies strongly positive. She has mild eyelid retraction and proptosis of 20 mm bilaterally without diplopia. She smokes 20 cigarettes daily. Which factor most increases her risk of progressive orbitopathy?
- A.Cigarette smokingCorrect
- B.Female sex
- C.Age under 40 years
- D.Presence of a diffuse goitre
Explanation
Cigarette smoking is by far the strongest modifiable risk factor for Graves orbitopathy, increasing both the likelihood of developing eye disease and its severity, and smokers respond less well to immunosuppression and orbital radiotherapy. Tobacco appears to act through hypoxia and oxidative stress on orbital fibroblasts, which stimulates glycosaminoglycan production, adipogenesis, and inflammatory cytokine release, expanding the retro-orbital tissue within a fixed bony orbit. The underlying pathogenesis is antibody stimulation of the thyroid-stimulating hormone receptor shared by orbital fibroblasts and the thyroid follicular cell, which is why thyrotropin receptor antibody titres correlate with eye disease severity. Smoking cessation is therefore the single most important intervention to offer this patient and should be documented at every visit. The other major modifiable risk is radioactive iodine therapy, which transiently worsens orbitopathy through antigen release, so it should be avoided or covered with corticosteroid prophylaxis in patients with active eye disease; uncontrolled hypothyroidism after treatment also aggravates the eyes. Female sex increases the incidence of Graves disease itself, but men who develop orbitopathy tend to have more severe eye disease, so being female is not a risk factor for progression. Older rather than younger age is associated with more severe orbitopathy. A diffuse goitre is simply a feature of the disease and carries no independent predictive value for eye involvement. Selenium supplementation benefits mild active disease, and teprotumumab, an insulin-like growth factor 1 receptor antibody, is now used for moderate to severe active orbitopathy.
Why each option
- A.
- Correct. Smoking is the strongest modifiable risk factor for developing and worsening Graves orbitopathy and blunts response to treatment.
- B.
- Female sex raises the incidence of Graves disease overall, but male patients actually tend to develop more severe orbitopathy.
- C.
- Younger age is associated with milder eye disease; severity increases with advancing age.
- D.
- A diffuse goitre is a manifestation of the disease and does not independently predict orbital involvement.
Reference: 2021 European Group on Graves' Orbitopathy (EUGOGO) Clinical Practice Guidelines
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