Surgery: Ophthal Flashcards
What are the features of diabetic retinopathy?
Background: venodilation, microaneurysms, hard exudates
Pre-Proliferative: soft exudates
Proliferative: new vessel formation
What are the features of hypertensive retinopathy?
I: arteriolar narrowing + silver wiring
II: AV nipping
III: flame shaped haemorrhages + cotton wool spots
IV: papilloedema = raised IOP
What should you listen for if the pt complains of amaurosis fugax?
Carotid Bruits
What causes pupil constriction?
Acetylcholine - PNS - Circular Muscles
List causes of miosis (4)
Constricted pupil: horners, cluster headaches, Argyll-Robertson, drugs
Horner’s Syndrome Triad
Ptosis
Miosis
Anhidrosis - pre ganglionic affects face, central affects face arms trunk, post ganglionic not affected
What are the causes of Horner’s syndrome?
Pre-Ganglionic Lesion: Trauma Top Rib Thyroidectomy pancoast Tumour
Central Lesion: Stroke Syringomyelia multiple Sclerosis tumour Swelling
Post-Ganglionic Lesion: Carotid Aneurysm Carotid Artery Dissection Cavernous Sinus Thrombosis Cluster Headache
Argyll-Robertson Pupil
Bilateral, accommodates but does not react, neurosyphilis
Damage to the pretectal region in the midbrain
The nickname prostitutes pupil helps remember the O/E and cause
What causes pupil dilation?
Adrenaline - SNS - Dilator Muscles
List causes of mydriasis (6)
Dilated pupil: third nerve palsy, raised ICP, Holmes-Adie, congenital, trauma, drugs
3rd Nerve Palsy Triad
Ptosis
Mydriasis
Divergent strabismus in a down and out position
What are the causes of a 3rd nerve palsy?
Idiopathic
Medical - ischaemia - Pupil Sparing: HTN, DM, MS
Surgical - pressure on PNS - Pupil Dilatation: painful PCOM aneurysm, cavernous sinus thrombosis, tumour, trauma, raised ICP
Think PHD: PCOM, HTN, DM
Holmes-Adie Pupil
Unilateral, Sluggish, Viral
Damage to post ganglionic parasympathetic fibres
Syndrome = pupil + absent ankle and knee reflexes
Which CN has the longest intracranial route?
Abducens
Ddx of Red Eye
Painful: orbital cellulitis, herpes, dryness, keratitis, ulcer, uveitis, scleritis, acute glaucoma
Painless: episcleritis, trichiasis, subconjunctival haemorrhage
Both: blepharitis, viral>allergic>bacterial conjunctivitis, foreign body
Which viruses can cause keratitis? (3)
Herpes simplex, VZV, adenovirus
What can happen when contact wearers go swimming?
Keratitis caused by acanthamoeba
What constitutes the uveal tract? (3)
Iris, ciliary body, choroids
How does corneal pathology and uveitis classically present? (3)
Usually recurring w photophobia, watering, pain
How does orbital cellulitis px? (3)
Unilateral, ophthalmoplegia, proptosis
What can mimic the cobblestone papillae in conjunctivitis?
The use of contacts
Painless + sudden loss of vision
Retinal artery occ: emboli, GCA + fundoscopy shows retinal pallor and cherry red spot
Retinal vein occ: thrombus, myeloma + fundoscopy shows haemorrhages, cotton wool spots, swollen optic disc
Which muscles other than the extraocular are paralysed following a 3rd nerve palsy?
Levator palpebrae superioris + pupillary constrictor
Why is the eye ‘down and out’ in 3rd nerve palsy?
Unopposed SO and LR action