Thyroid eye disease

(aka Grave's Ophthalmoplegia, Hyperthyroidsim Related Infiltrative Ophthalmoplegia, Thyroid Associated Orbitopathy)

Enlargement of the extraocular muscles caused by T-lymphocyte infiltration, adipose hypertrophy, scarring and irreversible proptosis.

Order of Extraocular Muscle Involvement (I'M SLO)

• Inferior rectus
• Medial rectus
• Superior rectus
• Lateral rectus - if isolated lateral rectus think orbital pseudotumor
• Obliques

• Bilateral and symetric involvement is typical
• Tendon is typically spared (unlike orbital pseudotumor)
• Can be exacerbated by radioiodine therapy (prednisone can prevent flare)
• Eye complications occur in 25-50% of Grave's
• Painless

Differential

• Lymphoma
• Orbital pseudotumor - idiopathic painful inflammation, "dirty fat"
• Sarcoidosis
• Tolosa Hunt syndrome - painful opthalmoplegia caused by cavernous sinus inflammation (likely continuum of orbital pseudotumor)