Thyroid Eye Disease

Question 1

How often is thyroid eye disease seen?

Answer 1

Seen in 25-50% of those people with Grave’s disease as well as people with thyroid disease without Grave’s disease. The disease may not correlate to thyroid status and patients may be euthyroid or it may be the first presentation of thyroid disease.

Question 2

What is the main risk factor for thyroid eye disease?

Answer 2

The main risk factor is smoking.

Question 3

What causes thyroid eye disease?

Answer 3

The condition occurs as a result autoimmune response via an autoantigen possibly to the TSH receptor leading to retro-orbital inflammation and white cell infiltration resulting in swelling of the orbit, particularly the extra-ocular muscles due to glycosaminoglycan and collagen deposition.

Question 4

How does thyroid eye disease present?

Answer 4

Often bilateral 
Eye discomfort 
Grittiness
Increase tear production and consequent watering 
Photophobia
Diplopia 
Reduced acuity 
Colour-blindness

Question 5

What are the signs of thyroid eye disease?

Answer 5

RAPD
Exophthalmos – protruding eye and proptosis (eye protrudes beyond the orbit)
Conjunctival oedema – chemosis
Optic disc swelling (as eye swells it moves outwards putting pressure on the optic nerve)
Corneal ulceration – due to problems closing the eyelid and can cause exposure keratopathy
Ophthalmoplegia especially upward gaze

Question 6

What investigation should be done in a thyroid eye disease presentation?

Answer 6

A scan and B scan USS

CT/MRI may show swelling of the eye muscles

Question 7

How is thyroid eye disease managed?

Answer 7

Treat thyroid disease but note radioiodine increases the inflammatory response and should be avoided in active disease.

If severe – high dose steroid preferably methylprednisolone
Radiotherapy
Surgical decompression if sight threatening of for cosmetic once eye has calmed down

Question 8

What general advice can you give to someone with acute thyroid eye disease?

Answer 8

Stop smoking
General stuff – artificial tears, taping the lid shut/protective shields, sunglasses, elevate bed to reduce oedema, Fresnel prisms for diplopia.

Question 9

When should patients with thyroid eye disease be urgently referred to an ophthalmologist?

Answer 9

Urgent review by ophthalmologist if:
Unexplained deterioration in vision
Awareness of change in intensity or quality of colour vision in one or both eyes
History of eye suddenly popping out (globe subluxation)
Obvious corneal opacity
Corneal still visible when eyelids are closed
Disc swelling