opthal Flashcards
Retinal vessel occlusion - ARTERY - 3 x types
CRAO
Branch retinal artery occlusion
Cilioretinal artery occlusion
Retinal vessel occlusion - VENOUS - 2 x types
CRVO
Branch retinal vein occlusion
CRAO sx (2) + fundoscopy findings
sudden painless TOTAL loss of vision + RAPD
F-globally pale retina + cherry red macula
Branch retinal artery occlusion
sudden painless PARTIAL loss of vision
NO RAPD
F-focal ischaemic region corresponding to visual loss
Cilioretinal artery occlusion
Painless CENTRAL vision loss
- 15-30% population
- equally if CRA present and CRAO occurs, central vision may be retained
Retinal vessel occlusion -ARTERY -IX + MX
IX: CVS RF HX (echo, carotid dopplers), T.A. biopsy, ESR
MX: eyeball massage, carbogen therapy (inhale 5% CO2, 95% O2), haemodilution, vasodilators, decrease intraocular pressure
Retinal vessel occlusion -VENOUS - IX + MX
Ix: fluorescein angiography (ischaemic vs non-ischaemic CRVO)
Mx (only ischaemic CRVO): pan-retinal photocoagulation
CR VEIN O 2x types + sx
Ischaemic + Non-Ischaemic
Ischaemic - sudden painless TOTAL loss of vision (usu unilat) + RAPD
fundoscopy -widespread hyperemia, severe retinal H ‘stormy sunset’
Non-isch - SUBACUTE mild-mod loss of vision + NO RAPD
BRVO sx
ASYMPT - unless involving macula
-cause = blockage of retinal veins at AV crossings
endopthalmitis
red eye, pain and reduced vision following intraocular surgery
anterior uveitis
acute onset
pain
blurred vision and photophobia
small, fixed oval pupil, ciliary flush
hyp retinopathy stage I
arteriolar narrowing + tortuosity, incr light reflex, silver wiring
hyp retinopathy stage II
AV nipping
hyp retinopathy stage III
cotton wool exudates + flame + blot H
hyp retinopathy stage IV
papilloedema
RAPD/Marcus-Gunn pupil how is it found, what is finding + what is it caused by
- swinging light test –> affected + normal eye BOTH DILATE when light shone onto affected eye
- causes: retina detatchment, optic neuritis eg MS
pathway of pupillary light reflex - afferent and efferent
afferent: retina → optic nerve → lateral geniculate body → midbrain
efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve
retinal detachment 4Fs
Floaters
Flashes
Field loss
Fall in acuity
-sudden painless loss of vision - char by dense shadow starting peripherally + progressing centrally
horners - central lesions SSS
anhidrosis of FACE, ARM, TRUNK Stroke MS Syringomyelia Tumour Encephalitis
Horners - pre ganglionic TTT
Anhidrosis of FACE pancoast Tumour Thyroidectomy Trauma Cervical rib
Horners - post ganglionic CCCC
no anhidrosis Carotid artery dissection Carotid aneurysm Cavernous sinus thrombosis Cluster headache
immediate mx of AACG
combination of eye drops, for example:
-a direct parasympathomimetic (e.g. pilocarpine, causes contraction of the ciliary muscle → opening the trabecular meshwork → increased outflow of the aqueous humour)
a beta-blocker (e.g. timolol, decreases aqueous humour production)
-an alpha-2 agonist (e.g. apraclonidine, dual mechanism, decreasing aqueous humour production and increasing uveoscleral outflow)
-intravenous acetazolamide- reduces aqueous secretions
definitive mx of AACG
laser peripheral iridotomy
-creates tiny hole in peripheral iris –> aqueos humour flowing to angle
define + causes of tunnel vision
Tunnel vision is the concentric diminution of the visual fields -Causes: papilloedema glaucoma retinitis pigmentosa choroidoretinitis optic atrophy secondary to tabes dorsalis hysteria
papilloedema define
optic disc swelling caused by incr IOP - almost always BILATERAL
papilloedemA on fundoscopy
- venous engorgement: usually the first sign
- loss of venous pulsation: although many normal patients do not have normal pulsation
- blurring of the optic disc margin
- elevation of optic disc
- loss of the optic cup
- Paton’s lines: concentric/radial retinal lines cascading from the optic disc
causes of papilloedema
- space-occupying lesion: neoplastic, vascular
- malignant hypertension
- idiopathic intracranial hypertension
- hydrocephalus
- hypercapnia
what is most common cause of blindness >60Y
ARMD - 90% Dry, 10% Wet
ARMD key features
- Degeneration of the CENTRAL RETINA (MACULA) is the key feature with changes usually BILATERAL
- ARMD is characterised by degeneration of retinal photoreceptors that results in the formation of DRUSEN which can be seen on fundoscopy and retinal photography
- It is more common in -OLD - FEMALES
ARMD RF
- old age
- smoking
- FHx
- CVD RF
Blepharitis define + cause
= inflammation of the eyelid margins.
- It may due to either meibomian gland dysfunction (common, posterior blepharitis) or seborrhoeic dermatitis/staphylococcal infection (less common, anterior blepharitis)
- Blepharitis is also more common in patients with rosacea
Blepharitis features
BILATERAL GRITINESS + DISCOMFORT -eyes sticky in AM -eyelid margins red -styes + chalazions more common in pts with Bleph -secondary conj may occur
Blepharitis Mx
- softening of the lid margin using hot compresses twice a day
- ‘lid hygiene’ - mechanical removal of the debris from lid margins
- cotton wool buds dipped in a mixture of cooled boiled water and baby shampoo is often used
- an alternative is sodium bicarbonate, a teaspoonful in a cup of cooled water that has recently been boiled
- artificial tears may be given for symptom relief in people with dry eyes or an abnormal tear film
classification of squints by where eye deviates toward on cover test
Squints may be classified as to where the eye deviates toward the nose: esotropia temporally: exotropia superiorly: hypertropia inferiorly: hypotropia
3rd N P vs HS
Ptosis + dilated pupil = third nerve palsy
ptosis + constricted pupil = Horner’s
Optic Neuritis Sx CRAP
EYE MVMNTS HURT Central scotoma RAPD Acuity loss - central vision, colour vision Pain on mvmnt
optic neuritis causes
MS
DM
Drugs- ethambutol, chloramphenicol
Inf - VZV, Lyme
Argyll-Robertson Pupil
Acommodation reflex present (ARP) but (PRA) pupillary reflex absent
