Epidemiology of dysthyroid eye disease

• clinically evident in 25-50% of patients with Graves' hyperthyroidism - occurs occasionally in patients with Hashimoto's thyroiditis and in those with Graves' disease but no evident thyroid disease.
  
  
• the mean age is 45 years and the female:male ratio is 2:1
  
  
• there is an association with cigarette smoking, as 90% of cases occur in smokers
  
  
• return to normal thyroid function is associated with improvement in the eye disease
  
  
• association with HLA-DR3
  
  
• Graves' hyperthyroidism and Graves' ophthalmology are overlapping, if not concurrent, conditions - many patients with Graves' hyperthyroidism but no clinical eye features can be shown to have evidence of ophthalmological changes with techniques such as orbital MRI - similarly many euthyroid patients with Graves' ophthalmology can be shown to have laboratory evidence of thyroid autoimmune disease.
  
  
• in 85% of patients affected by either Graves' hyperthyroidism or Graves' ophthalmology, the other develops within 18 months.

Reference:

• 1) Shine B et al (1990).Association between Graves' ophthalmology and cigarette smoking. Lancet, 335, 1261-3.
• 2) Tallstedt L et al (1992).Occurence of ophthalmology after treatment of Graves' hyperthyroidism.NEJM, 326, 1733-8.
• 3) Epstein FH (1993).Pathogenesis of Grave's ophthalmology. NEJM, 329(20),1468-75.