2.2 Thyroid Eye Disease II

Question 1

Name some differentials for TED

Answer 1

• Orbital injury (eg blow out fracture)
• Orbital inflammation
• Space occupying lesion (orbital tumour)
• Iatrogenic
• CPEO (chronic progressive external ophthalmoloplegia)
• MG (myasthenia gravis)
• Ocular myositis

Question 2

How is visual activity effected by TED?

Answer 2

• Corneal involvement due to exposure
• Induced refractive error (therefore important to pinhole)
• The optic nerve is compressed by grossly enlarged extraocular muscles

Question 3

How does TED effect each of the OMs?

Answer 3

• Typically IR fibrosis causes a hypo deviation. Maximum in elevation +/- small degree of excyclotorsion. CHP – chin elevation for comfort.
• MR fibrosis leads to an eso deviation due to abduction deficit.
• SR fibrosis leads to a depression deficit, usually maximum in abduction and adduction.
• It is common to see an eso and a hypo deviation together.
• These deviations can be manifest or latent – patients can have extended fusional reserves due to the gradual onset.

Question 4

What are some orbital examination/observations that can be done to identify TED?

Answer 4

• Lid lag (von Graefe’s sign) – delay in moving the eyelid as the eye moves downwards.
• Measure the PF.
• Look at the levator function (distance lids travel while frontalis muscle is held inactive at the brow).
• Marginal fold distance (from upper eyelid margin to fold of skin)
• Abnormalities of tear production
• Lower eyelid laxity or scleral show
• Lagophthalmos (difficulty in complete closure of the eyelid over the eyeball).
• Eyelid retraction

Question 5

What are some enhanced orthoptic assessment tests that can be done in TED examination?

Answer 5

• IOP – iCare - (normal range 10-21mmHg)
• Proptosis – Hertel exophthalmometer (normal range 12-21mm)
• Colour vision – Ishihara – indication of optic nerve compression.

Question 6

What are the visual aims for us in TED?

Answer 6

• Watch for stabilisation of OM
• Centralise and enlarge the field of binocular single vision where possible
  o Prisms
  o CHP
  o Bangerter foil
  o Patch

Question 7

How can TED be prevented?

Answer 7

• Stabilise thyroid function – regular blood tests required
• Selenium – can be taken as a supplement (2/3 brazil nuts per day)
• Probiotics
• Smoking cessation - smoking and vaping increases the risk of TED in Graves’ disease by 7x. The number of cigarettes smoked per day influences the incidence of proptosis and diplopia.

Question 8

How can TED be investigated?

Answer 8

• Blood tests – TSH receptor antibodies, TSH, FT3, FT4
• CT scans and MRI imaging – shows large muscles within the orbit. It is important to scan in cases of unilateral proptosis to exclude an orbital tumour.

Question 9

What are the different treatments for TED?

Answer 9

• Radioactive iodine – can increase the risk of new or worsened TED symptoms
• Thyroidectomy – reduces the risk of TED
• Teprotumumab – can significantly reduce proptosis
• Conservative medical management – topical therapy – to aid with sore and red eyes caused by conjunctival injection and chemosis. – Artificial tears, tape eyes closed at night and clingfilm to create a ‘greenhouse’ over the eyes at night.

Question 10

What treatment is not recommended for patients with TED and why?

Answer 10

• Radioactive iodine – can increase the risk of new or worsened TED symptoms

Question 11

What are the aims of the different medical management options?

Answer 11

• Aim of treatment – suppress orbital inflammation and reduce tissue changes in the EOM, orbital fat and periocular soft tissues.
• Preservation of sight is the priority
• Initially high-dose steroids – reduce inflammation and thereby reduce pressure on the optic nerve.
• Radiotherapy treatment – avoid in cases of TED, if cannot avoid give steroid cover. Can increase the risk of TED.
• Immunosuppressive therapy – improve congestive changes. Main treatment for active moderate to severe TED.

Question 12

What are the 3 different surgical management options in order?

Answer 12

1. 1st - Decompression surgery – proptosis, cosmetic improvement or VA risk
2. 2nd – Strabismus surgery – recession MR/IR, improve OM caused by mechanical restriction, correction cosmetic defect.
3. 3rd – Lid surgery

Question 13

What is TEAMeD?

Answer 13

• This project, supported by ophthalmologists and endocrinologists, aims to improve the care for people in the UK suffering from TED. This involves putting measures in place to ensure access to information, early diagnosis, appropriate treatment, and access to skilled professionals offering high standards of joint care.

Question 14

What are the 5 different steps in TEAMeD?

Answer 14

1. DIAGNOSE Graves’ disease accurately
2. SCREEN all patients for early symptoms and signs of TED
3. ALERT patients with Graves disease to early symptoms of TED
4. PREVENT, reduce the incidence of TED in Graves disease by smoking cessation, early induction, and maintenance of euthyroidism and avoidance of radioactive iodine treatment in active TED.
5. REFER, prompt referral of patients who develop TED directly to a regional multidisciplinary clinic with extensive experience of managing TED.

Question 15

What is the orthoptist’s role in TED?