Week 2 - G - Ophthamology 6 - Thyroid eye/Sjorgen's/Optic neuritis, Horners Flashcards
What is the difference between exopthalmos and proptosis?
Proptosis can refer to any organ that is pushed forward
Exopthalmos only refers to the eyes being the bulging of the eyes
What are extraocular signs of thyroid eye disease? Thyroid eye disease is relevant to hyperthyroidism
Exopthalmos, lid oedema and retraction and lag
What are ocular signs of thyroid eye disease?
Chemosis - oedema of the conjunctiavae - can see the chemosis here redeness of the eye (injection)
Why does the eye buldge forward in Grave’s? (exopthalmos is exclusive to grave’s)
The autoimmune anitbodies in Graves (anti-TSH antibodies, TRabs(TSH receptor antibodies)) inflame the muscles and fat in the eye causing them not to function and the eye bulges forward
What is the treatment of hyperthyroidism?
Give patient Carbimazole as first line
If contraindicated give propylthiouracil
If the patient begins to develop ulcers, fevers and sore throat when on carbimzole What is this? What should they do?
This is agranulocytosis - seen in treatment with carbimazole
It is due to a deficiency of WBC -leukopenia
They should be immediately taken off and switched to propylthiouracil
In hypothyroidism, what can happen to the eyebrow?
It is common to have a loss of the outer 1/3rd of the eyebrow
Why in hypothyroidism can you get increased lactation? What is the most common cause of hypothyroidism? What is the most common antibody in this common cause?
In hypothyrodism , because of the main cause which is anti-TPO antibodies - seen in Hashimotos thyroiditis, this causes a decrease in T4 and T3 levels
This acts as negative feedback to increase TRH and TSH hormones
TRH causes increased production of thyroid hormones and prolactin
What other autoimmune conditions is Hashimoto’s thyroiditis associated with?
Associated with pernicious anaemia - Pernicious anaemia is the most common cause of vitamin B12 deficiency as it attacks the cells in the stomach which produce intrinsic factor required for B12 absorption
Vitamin B12 is needed for normal RBCs
Diabetees mellitus
Addisons disease
Keratoconjunctivitis sicca - dry eyes Xerostomia - dry mouth Rheumatoid arthritis usually What syndrome is this?
This is Sjorgen’s syndrome
What glands does sjorgen’s syndrome affect and what are the antibodies in sjorgen’s syndrome?
Massive parotid gland swelling and lacrimal gland swelling
Antibpdies are anti Ro and anti La antibodies
What are the causes of the dry mouth and eyes in sjorgen’s syndrome? What test is done to check for dry eyes?
The autoimmune destruction of the salviary (dry mouth ) and lacrimal (dry eyes) glands cause the dry eye Schrimer’s test is done to check for the dry eyes
What drug can help with both the treatment of the dry eyes and mouth if the artifical tears and salivary substitutes are not affective?
Topical pilocarpine can help stimulate secretion by the exocrine glands This is a cholinergic drug
What is the treatment gven for severe dry eyes?
Topical ciclosporin
What other rhuematological condition may cause keratoconjunctivits sicca? It is also associated with slceritis/episcleritis
Rheumatoid arthritis
common condition caused by blunt injury to the eye. It is characterized by decreased vision in the injured eye a few hours after the injury. It causes what is known as a bruised retina What is the medical name for this?
Commotio retinae
If suspecting a corneal abrasion, what dye is give to identify this?
Give the patient fluorescein dye - identifies the area of epithelial loss
In trauma always carry out visual acuities, if there is blood in the anterior chamber, what is this called and what should you do?
This is an hyphaema - refer to ophthamology
If a patient presents with a chemical burn, is acid or alkali more dangerous and what is the treatment?
Alkali is more addangerous as it can penetrate into intracular structures Treatment is (solution to pulliton is dilution) by irrigation with 2L saline fluid (0.9% NaCl)
• Penetrating injury to one eye exposure of intra-ocular antigens auto-immune reaction in both eyes What is this and what can it cause?
This is sympathetic opthalmia and can cause bilateral blindness
What is the injured eye and what is the contralateral eye known as in sympathetic ophthalmia?
Injured eye - exciting eye Contralateral eye - sympathising eye
What type of uveitis is described in sympathetic ophthalmia?
Granulomatous uveitis due to the inflammation in the eye
What is the immediate management of a patient presenting with sympathetic ophthalmia?
Give patient topical and systemic steroids
• Progressive visual loss (unilateral) • Pain behind eye, especially on movement What is this?
This is optic neurtis
What is the vision loss in optic neuritis described as? Which vision is lost?
Described as a central scotoma and loss of colour vision
Which drug used in the treatment of tuberculosis causes optic neuritis?
- Rifampicin - Hepatotoxic and GI
- Isoniazid - hepatotoxic and peripheral neuritis
- Pyrazinimde - hepatotoxic and gout
- Ethambutol - Optic neuritis
Which disease is associated with optic neuritis leading to demyelination of the optic nerve?
MS - multiple sclerosis
Why is there painful eye movement in optic neuritis? (relates to where the extraocular muscles insert)
Due to the extraocular muscles inserting into the common tendinous ring, when they contract to move the eye this will cause movement of the optic nerve and therefore pain
Which extraocular muscles insert at the common tendinous ring and which do not?
Lateral, medial, superior and inferior rectus All the rectus muscles attach to the common tendinous ring The superior and inferior oblique do not Also the levator palpabrae superioris does not
What is the nerve supply to all the extraocular muscles?
Superior, medial and inferior rectus - oculomotr nerve Inferior oblique - oculomotor nerve Levator palpebrae superioris - oculomotor nerve Superior oblique - trochlear nerve Lateral rectus - Abducent nerve
What is the treatment for otpic neuritis?
It is self limiting so will gradually recover Can use oral steroids (prednisolone)
What are the four signs of horner’s sydnrome?
Miosis - constricted pupil Annydrosis - lack of sweating face Ptosis - drooping eyelid Enopthalmos - sunken eyeball
Horners is caused by disruption to the cervical sympathetic ganglion Give three example causes of horner’s syndrome?
Klumpke’s palsy- lower brachial nerve palsy (C8 and T1) Pancoast tumour of the lung Cervical rib - can impede stellate ganglion
What two ganglia join to make the stellate ganglion of the sympathetic chain?
Inferior cervical ganglion and T1
In Horner’s what is the muscle in the eyelid that is supplied by sympathetics and cause elevation of the eyelid? (it adjoins the levator palpabrae superioris)
This is the superior tarsal muscle (Muller’s muclse) - it is a smooth muscle supplied by sympathetics
What does the sympathetic supply to cause miosis if damaged?
They supply the dilator pupillae of the eye whcih cause dilation of the pupil These dilator pupillae are also known as radial pupillae When injured they cannot contract to dilate the eye
What are the 3 parts of the uvea?
Choriod , iris and ciliary muscles
Chorioretinitis is an inflammatory condition affecting the choroid and the retina Usually asymptomatic unless affecting the macula What can the infection cause on the macula? What causes chorioretinitis?
Causes a granulomatous reaction on the macula
Caused by either congenital toxoplasmosis (spread in cat faces) or CMV
Symptoms - floating black spots, blurred vision, pain or redness in the eye
