Thyroid Eye Disease (Graves Ophthalmopathy)

Key Features

• A syndrome of clinical and orbital imaging abnormalities caused by deposition of mucopolysaccharides and infiltration with chronic inflammatory cells of the orbital tissues, particularly the extraocular muscles

• The early inflammatory stage typically lasts 18–36 months, during which there is active lymphocytic infiltration into retrobulbar tissues

• The active inflammatory stage then tends to evolve to a chronic, fibrotic, "burned out" stage in which treatment of the exophthalmos is medically resistant to glucocorticoid treatment

• Radioiodine therapy, possibly indirectly due to induction of hypothyroidism, and cigarette smoking increase its severity

• Ethanol injection of thyroid nodules has been reported to be followed by severe disease

Clinical Findings

• Primary clinical features

  • Upper eyelid retraction (Dalrymple sign)

  • Lid lag with downward gaze (von Graefe sign)

  • Staring appearance (Kocher sign)

• The following can also be seen:

  • Proptosis

  • Conjunctival chemosis and episcleral inflammation

  • Weakness of upward gaze (Stellwag sign)

• Corneal drying may occur with inadequate lid closure

• Eye changes may sometimes be asymmetric or unilateral

• Resulting symptoms

  • Cosmetic abnormalities

  • Surface irritation, which usually responds to artificial tears

• Patients with severe exophthalmos can experience

  • Diplopia from extraocular muscle entrapment

  • Optic nerve compression, causing loss of

    • Color vision

    • Visual acuity

    • Visual fields (inferior especially)

• Symptoms of active retrobulbar inflammation include

  • Retrobulbar aching

  • Orbital inflammation and edema worse after recumbent sleep

  • Edematous or erythematous eyelids

  • Conjunctival redness or chemosis (edema)

  • Recent progression in exophthalmos

  • Recent diplopia or strabismus

  • Recent loss of visual acuity

• Differential diagnosis

  • Congenital proptosis

  • Asymmetry in orbital protrusion

  • Dural carotid-cavernous sinus fistula

  • Ocular myasthenia

Diagnosis

• Exophthalmometry should be performed on all patients with Graves disease to

  • Document the degree of exophthalmos

  • Detect progression of orbitopathy

• The protrusion of the eye beyond the orbital rim is measured with a prism instrument (Hertel exophthalmometer)

• Maximum normal eye protrusion varies between kindreds and races

  • About 24 mm for Black patients

  • About 20 mm for White patients

  • About 18 mm for Asian patients

Treatment

• General eye protective measures include wearing glasses to protect the protruding eye and taping the lids shut during sleep if corneal drying is a problem

• Methylcellulose drops and gels ("artificial tears") may also help

• Mild disease: Oral selenium (100 mcg twice daily) may slow progression

• The Mourits clinical activity score

  • Helps grade the severity of thyroid eye disease

  • Therapy in addition to selenium is warranted for active thyroid eye disease with a clinical activity point score ≥ 3

  • One point is given for each of the following manifestations:

    • Pain or pressure in the periorbital area

    • Pain with eye movement

    • Swelling of the eyelids

    • Erythema of the eyelids

    • Conjunctival injection

    • Chemosis

    • Caruncle inflammation

    • Increase in proptosis of ≥ 2 mm within 3 months

    • Decrease in eye movement within 3 months

    • Decrease in visual activity within 3 months

• Intravenous pulse methylprednisolone

  • Dosage: 500 ...