Thyroid eye disease

Question 1

What is thyroid eye disease?

Answer 1

Thyroid eye disease (TED) is an autoimmune condition resulting in inflammation and swelling of the extraocular muscles, fatty tissue and connective tissue within the orbit.

Question 2

Who does thyroid eye disease occur in most commonly?

Answer 2

ED commonly occurs in patients with Graves’ disease but can present in euthyroid or hypothyroid patients. In most patients, eye disease and thyroid issues evolve within 1.5 years of each other.

Question 3

What is the pathophysiology of thyroid eye disease?

Answer 3

Closely correlating with Graves’ disease, patients with TED have been found to have elevated levels of antibodies against thyroid-stimulating hormone (TSH) receptors, which are expressed in orbital fat and connective tissue.

Studies also attribute increased fibroblast activity as well as the accumulation of collagen and hyaluronic acid to the enlargement and fibrosis of the extraocular muscles.

Question 4

What are the 3 risk factors for thyroid eye disease?

Answer 4

1. Smoking
2. Previous radioiodine therapy
3. Men have more severe disease

Question 5

What are 4 typical symptoms of thyroid eye disease?

Answer 5

1. Excessive watering
2. ‘Gritty’ sensation
3. Photophobia
4. Eye pain

Question 6

What 3 other symptom is important to ask in a thyroid eye disease history?

Answer 6

1. Red eye
2. Blurred vision
3. Sensation of pressure

Question 7

What systemic signs of thyroid disease may patients also present with?

Answer 7

1. Pretibial myxoedema
2. Goitre
3. Acropachy

Question 8

Give 10 presentations associated with thyroid eye disease:

Answer 8

1) exophthalmos/ proptosis
2) eye lid retraction
3) lid lag
4) lid oedema
5) incomplete eye lid closure
6) eye pain
7) photophobia
8) excessive watering
9) diplopia
10) corneal exposure and ulceration

Question 9

What is Dalrymple’s sign?

Answer 9

eye lid retraction (seen in thyroid eye disease)

Question 10

What is Von Graefe’s sign?

Answer 10

lid lag (seen in thyroid eye disease)

Question 11

What is a sight threatening complication of thyroid eye disease?

Answer 11

compressive optic neuropathy - where the enlarged muscles and fat press on the optic nerve

Question 12

Give 2 presentations associated with compressive optic neuropathy:

Answer 12

1) reduced visual acuity
2) reduced colour vision

Question 13

What drug needs to be urgently given to those with thyroid eye disease and suspected compressive optic neuropathy?

Answer 13

IV methylprednisalone

Question 14

What does the mnemonic NO SPECS stand for?

Answer 14

N: No signs or symptoms
O: Only ocular irritation (dryness, gritty sensation)
S: Soft tissue involvement (conjunctival oedema or injection)
P: Proptosis
E: Extraocular muscle involvement
C: Corneal exposure and ulceration
S: Sight loss (due to compressive optic neuropathy)

Question 15

What laboratory investigations can be done to investigate thyroid eye disease?

Answer 15

1. Thyroid function test
2. Antibody testing

Question 16

Give two types of imaging used to investigate thyroid eye disease:

Answer 16

1) ultrasound - detect extraocular muscle enlargement
2) CT orbits - detect optic nerve involvement

Question 17

Give 3 management strategies for thyroid eye disease:

Answer 17

1) correct to euthyroidism
2) steroids e.g. methylprednisolone for severe swelling
3) surgery e.g. orbital decompression or lid surgery if there is significant corneal exposure

Question 18

What are 4 complications of thyroid eye disease?

Answer 18

1. Loss of sight secondary to compressive optic neuropathy
2. Globe subluxation_ eye ‘popping out’
3. Gaze abnormalities
4. Raised intraocular pressure leading to glaucoma

Question 19

What is exophthalmos?

Answer 19

exophthalmos is defined by the enhanced anteroposterior positioning of the eyeball, leading to protrusion beyond the orbit’s protective bony structure. This condition, often referred to as bulging eyes or proptosis, can affect one or both eyes. It’s worth noting that exophthalmos is not a disease but a physical sign of an underlying condition that warrants immediate medical attention.

Question 20

What is exophthalmos caused by?

Answer 20

Besides being a predominant sign of Graves’ disease, exophthalmos can also arise due to several other health conditions. Tumours in the orbit, cysts, or an overproduction of cells in the orbit due to an inflammatory disease are plausible causes. A rare cause could be chronic sinusitis, where the prolonged inflammation causes an accumulation of fluid, leading to the bulging of eyes.

Question 21

What are some associated symptoms of exophthalmos?

Answer 21

he symptoms associated with exophthalmos include a prominent bulging of the eyes, accompanied by dryness, irritation, discomfort, or pain in the eyes. There might also be excessive tearing or difficulty in closing the eyes completely. The patient may experience redness, swelling, a sensation of pressure, or a gritty feeling in the eyes. Depending on the underlying cause, individuals may also display signs such as increased sensitivity to light, double vision, or vision loss.