The eye in systemic disease

Question 1

How does a defect in eye movements present?

Answer 1

double vision

Question 2

What would a lesion in the 6th nerve cause?

Answer 2

a lateral rectus palsy and inability to abduct

Question 3

What is the number one cause of 6th nerve palsy?

Answer 3

microvascular disease

Question 4

Why is the 6th nerve susceptible to ICP?

Answer 4

curves over the petrous tip so can be pushed against it in increased pressure

Question 5

What should you look for if a patient presents with headache, vomiting and a convergence squint?

Answer 5

papilloemea

Question 6

What are the functions of SO?

Answer 6

medial rotation (intorsion); looking down when adducted

Question 7

What would be the sign of an SO palsy when the patient is looking straight ahead?

Answer 7

one pupil is slightly higher than the other (so superior oblique isnt balancing it)

Question 8

What are the features of bilateral trochlear plasy?

Answer 8

torsion and chin depression

Question 9

What causes bilateral IVth palsy?

Answer 9

blunt head trauma

Question 10

What are the causes of 4th nerve palsy?

Answer 10

congenital decompensated; microvascular; tumour

Question 11

What are the sighsn of a 3rd nerve palsy?

Answer 11

ptosis; dilated pupil; pupil down and out- only SO and LR working

Question 12

What is a 3rd nerve palsy caused by until proven otherwise?

Answer 12

circle of willis aneurysm

Question 13

What is more likley to be the cause if the pupil is not involved in a 3rd nerve palsy?

Answer 13

microvascular

Question 14

Why are hte parasympathetic fibres sometimes not involved?

Answer 14

they lie on the outside of the nerve

Question 15

What is the inter-nuclear pathway called?

Answer 15

medial longitudinal fasciculus

Question 16

What can cause problems with inter-nuclear ophthalmoplegia?

Answer 16

MS- demyelination; vascular

Question 17

What does the optic radiation pass through?

Answer 17

temporal and parietal lobes

Question 18

What can cause problems with the optci nerve?

Answer 18

ischaemic optic neuropathy; optic neuritis; tumours

Question 19

What are the sings of optic neuritis?

Answer 19

progressive visual loss (unilateral); pain behind eye esp. on movements

Question 20

What follows optic neuritis?

Answer 20

atrophy of the nerve

Question 21

What are the sings of optic atrophy?

Answer 21

pale and featureless disk

Question 22

What tumours can affect the optic chiasm?

Answer 22

pituitary tumour; craniopharyngioma; meningioma

Question 23

What can cause probelms in the occipital cortex?

Answer 23

vascular disease; demyelination

Question 24

What causes diabetic retinopathy?

Answer 24

chronic hyperglycaemia–glycosylation of protein/basmemnt membrane– loss of pericytes–microaneurysm (outpouching of capillary wall) which causes leakage and ischaemia

Question 25

What are the signs of non-proliferative retinopathy?

Answer 25

microaneurysms/ dot and blot haemorrhages; hard exudates; cotton wool patches; abnormalities of venous calibre- venous bleeding; intra-retinal microvascular abnormalities

Question 26

What happens as the basemenet membrane thickens?

Answer 26

hypoxia so body makes new vessels to compensate- prolferative retinopathy

Question 27

Why do new vessels leak?

Answer 27

not surrounded by pericytes

Question 28

How can you tell the difference bewteen new vessels and nomral vessels?

Answer 28

new vessels dont have a "purpose" or go somewhere

Question 29

What causes the loss of visiion in diabetic retinopathy?

Answer 29

retinal oedema affecting fovea; vitreous haemorrhage scarring

Question 30

What causes scarring in diabetic retinopathy?

Answer 30

new vessels are associated with fibrous tissue formation

Question 31

What are the features of hypertensive retinopathy?

Answer 31

attenuated blood vessels- copper or silver wiring; cotton wool spots; hard exudates; retinal haemorrhage; optic disc oedema

Question 32

What layer becomes swollen during central retinal artery occlusion?

Answer 32

retina nerve fibre layer

Question 33

Why is there a cherry red spot CRAO?

Answer 33

the fovea has no ganglion cells to swell up and so obscure the choroid and pigmented epithelium

Question 34

What are the signs of CRAO?

Answer 34

sudden painless loss of vision; pale retina except from fovea

Question 35

What is the visual loss in papilloedema?

Answer 35

none- except increased blind spot

Question 36

Why does hypertension increase risk of CRVO?

Answer 36

artery adn vein share same exit so hypertensive/ atherosclerotic artery presses on vein

Question 37

What are hte extra-ocular isgns of thyroid eye disease?

Answer 37

proptosis-swelling of extraocular muscles and orbital fat; lid retraction, oedema, lag and pigmentation; restrictive myopathy- difficulty moving eye and diplopia

Question 38

What are the ocular features of thyroid eye disease?

Answer 38

chemosis; injection; glaucoma; optic nerve swellign

Question 39

What happens in GCA to the eye?

Answer 39

massive infarction of optic nerve head

Question 40

What are teh eye features of RA?

Answer 40

keratoconjunctivitis sicca (dry eyes); scleritis; corneal melt

Question 41

What are the triad of features of sjogrens ?

Answer 41

keratoconjunctivitis sicca; xerostoma; arthritis

Question 42

What causes the dry eyes in Sjogrens?

Answer 42

infiltration of lacrimal glands

Question 43

How does Marfans affect the eyes?

Answer 43

affects the zonules of the eye ( suspensory ligamnet of the lens)

Question 44

What can occur as a result of conjuncitivits in stevens-johnson syndrome?

Answer 44

symblepharon- adhesion of eyelids to eyebal