Opthalmology Flashcards
Giant cell arteritis
Optic nerve ischaemia > sudden blindness
Iritis associations
AS, reiters, etc
Scleritis/ episcleritis
RA, SLE, vasculitis
Episcleritis not painful
Hypertensive retinopathy
BP accelerates atherosclerosis in retinal vessels.
Silver wiring - Hardened arteries are shiny and ‘nip’ veins where they cross
Cotton wool spots - Narrowed arterioles > blocked > localized retinal infarction
Leaks from these in severe HTN > hard exudates or macular oedema.
Papilloedema or flame haemorrhages
suggest accelerated hypertension
Infective endocarditis
Roth spots - small retinal infarcts
Retinal vein occlusion
HTN, age, hyperviscosity
Stormy sunset (fundus) - central vein, if branch then wedge of retina
Acute drop acuity
AIDS HIV
CMV retinitis, lone cotton wool spots - HIV retinopathy
Acute glaucoma
Both ciliary and conjunctival vessels injected. Entire eye is red. Injected iris Pupil dilated, fixed Cornea hazy Anterior chamber very shallow High intraocular pressure
Open angle - blockage in drainage of aqueous humour
> increased IOP
Chronic
Tx - prostaglandin analogue (latanoprost) - relaxes ciliary muscules > lowers IOP
laser - open angle
Closed - angle between iris and cornea too small (lens being pushed against iris) > block
Acute - IV acetazolomide - carbonic anhydrase inhibitor - diuresis
pilocarpine drops
peripheral iridotomy - closed angle
Iritis
Injected iris
Pupil adhesions so irregular
Redness most marked around cornea, which
doesn’t blanch on pressure.
Usually unilateral.
Causes: AS, RA, Reiter’s, sarcoidosis, HSV, herpes zoster, and Behçet’s disease.
NB: a similar scleral appearance but without
papillary or anterior chamber involvement
may be scleritis (eg RA, SLE, vasculitis).
Refer -steroid eye drops
Conjunctivitis
Often bilateral. Conjunctival vessels injected, greatest toward fornices, but blanching on pressure. Mobile over sclera. Purulent discharge.
Subconjunctival
haemorrhage
Causes: HTN; leptospirosis; bleeding
disorders; trauma; snake venom; haemorrhagic
fevers.
Dendritic ulcer
Photophobia & watering.
If steroid drops are used without aciclovir cover, corneal invasion and scarring may occur, risking blindness.
1% fluorescein drops stain the lesion. :
Aciclovir 3% eye ointment 5≈ daily.
Ophthalmic shingles
Pain and neuralgia in the distribution of
cranial nerve V1 dermatome
blistering rash. In 50% of those with HZO the
globe is affected (corneal signs ± iritis in >40%—
sectoral iris atrophy
Nose-tip (Hutchison’s sign) -nasociliary branch of the trigeminal nerve also supplies the globe >likely eye affected.
The eye can be affected with little rash elsewhere.
Varicella zoster virus (VZV) may persist in the eye.
The different patterns of retinal disease caused
by VZV relate to immune status.
Oral antivirals improve symptoms (additional antiviral drops are not needed) but cannot be relied on to prevent postherpetic neuralgia.
Famciclovir offers the best dose schedule (750mg once daily for 1wk; SE vomiting; headache) but is much more expensive than aciclovir (800mg 5 times daily
PO for 7 days—it has more serious SE such as hepatitis and renal failure).
Start within 4 days of onset. It is wise for all to see a specialist if the nose-tip is involved, or the eye turns red within 3 days, to exclude anterior uveitis with a
slit lamp. Prolonged steroid eyedrops may be needed.
Retinoblastoma
most common primary intraocular tumour in children
Strabismus and leukocoria
Autosomal dom
RB gene
5% occur with a pineal or other tumour
Secondary malignancies such as osteosarcoma and rhabdomyosarcoma
are more frequent
Third nerve palsy (oculomotor)
Ptosis (levator palpebrae), proptosis (as recti tone), fixed pupil dilatation (constrictor pupillae), with the eye looking down and out.
cavernous sinus lesions
superior orbital fissure syndrome
diabetes
posterior communicating artery aneurysm.
Fourth nerve palsy (trochlear)
Diplopia
patient may hold his head tilted (ocular torticollis).
The eye looks upward, in adduction and cannot look down and in ( paralysed).
Causes: Trauma 30%, diabetes 30%, tumour, idiopathic.
Trochlear - superior oblique - this looks down and out