Thyroid Ophthalmopathy

• Most common cause of proptosis in adults
• Typically occurs from 20-50 years old
• Patients are usually hyperthyroid, but may be euthyroid
• Neuroimaging usually reveals thick muscles with tendon sparing
  • Inferior rectus and medial rectus muscles are most commonly involved
  • Usually bilateral, but may be asymmetric

• Grave’s Disease = Diffuse Toxic Goiter
  • Autoimmune disorder with thyroid stimulating antibodies (LATS) producing hyperplasia and hypertrophy of thyroid gland
• Age of incidence
  • 3rd-4th decade
  • Female predominance 7:1
• Laboratory findings
  • Elevated T3 and T4
  • Depressed TSH production
• Clinical findings
  • Pretibial myxedema
  • Ophthalmopathy
    • Periorbital edema
    • Lid retraction
    • Opthalmoplegia
    • Proptosis
    • Malignant exophthalmos
  • Diffuse thyroid enlargement
• US
  • Identical to diffuse goiter
  • Global enlargement of 2-3 times normal size
  • Normal and/or diffusely hypoechoic pattern
  • Hyperemia on color Doppler

 
Thyroid Ophthalmopathy. Axial and coronal CT scans of the orbits show marked enlargement of the extraocular muscles with sparing of the tendons consistent with the ophthalmopathy seen with Grave's disease