Opthalmology Flashcards
What do you need to do for opthalmoscopy ?
dilate pupil by relaxing sphincter muscles
-Eg Atropine
[Tropicamide /
Cyclopentolate ]
Things to describe in the optic disk
Colour
Contour
Cup
Circulation
Name 3 causes of retinal haem
diabetic retinopathy, SAH, vasalva haemorrhage, hypertensive retinopathy,
What would a bright yellow ring around a central leak in opthamoscopy indicate ? mx if near macula?
fluid leakage
laser
What are cotton wool spots -
micro infarcts
What are drusen?
pale, round and grey. Seen at the macula in the elderly
-> sign of age-related macula degeneration
spidery black pigmentation in peripheral retina?
Retinitis pigmentosa
-inherited retinal degeneration
What is a scotoma
Cause of a central?
blind spot
lesion in the optic nerve between nerve head and chiasm
-Eg optic neuritis, MS
Macular degeneration leads to a central scotoma
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What is meant by congruity?
refers to the agreement of shape of the defect.
The closer to the visual cortex - the more congruous
What is a junctional scotoma
Lesion at junction of optic nerve and chiasm
->contralateral nasal fibres compressed because the nasal fibres dip into the optic nerve before travelling down the optic tract.
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What is a slit lamp used for
examining the anterior segment of the eye (i.e. infront of the vitreous body)
Small depression in centre of macula
fovea
Central/thickest part of retina, high concentration of cones
macula
Central retina, colour vision and acuity
Cones
Outer retina, night vision
rods
Highly pigmented and vascular layer below RPE, provides O2 req of outer retina
Choroid
How can you test acuity
snellen chart
What is a cataract
Any opacity or clouding of the lens, progressive over years, usually bilat
Name 3 rfs of cataract
Sunlight, age, smoking, alcohol, corticosteroid, DM
What is meant by ‘the angle’ in open angle glaucoma
Space between posterior surface of cornea and anterior surface of iris.
Where the aqueous humour leaves the eye.
Where is aqueous humour produced?
what does it do?
Ciliary body, circulates and nourishes lens.
What is chronic open angle glaucoma? (its the most common)
O/E?
Chronic, progressive, optic neuropathy with characteristic changes in optic nerve head and corresponding visual field loss
3 THINGS:
- enlargement of optic disc cup (loss of neurones)
- Progressive visual field loss -> tunnel vision
- raised intraocular pressure (>21) - however this is not always present because some people can have normal pressure glaucoma
Triad of glaucoma
Raised IOP (>21mmHg) - not always present
Abnormal disc - cup:disc ratio - (cup gets bigger ) asymmetry, disc haemorrhage etc
VF defect - tunnel vision
3 Ix in screening of chronic open angle glaucoma
IOP - low specificity, high FPR
VF test - high FPR
Fundoscopy - cupping - high FPR
Drops for open angle glaucoma
Beta blockers - timolol
[reduces aqueous production] - B for BLOCK production
Prostaglandin analogue - latanoprost
[increases outflow]
If drops dont work / lack of compliance what can you do for glaucoma ?
Post these mx?
Laser therapy (trabeculoplasty)
/
Surgery (trabeculotomy)
-> Dexamethasone (can’t find this in nice guidelines)
what 3 things is visual acuity dependent on?
Functional photoreceptors (rods/cones)
Healthy retinal pigment epithelium (RPE)
Perfusion of choroid (capillary layer)
First thing you develop in macular degeneration
drusen
Seen on opthalmoscope of dry macular degeneration?
visual field loss?
On opthalmoscope
- Atrophy of RPE (visible choroidal arteries)
- drusen
Visual field loss
Central scotoma with preserved peripheral vision
Seen on opthalmoscopy of wet macular degeneration? Visual field loss?
Choroidal neovascular membrane (CNVM)
Leaking vessels below retina
Exudates and haemorrhage and scarring
distorted central vision (objects distorted or appear smaller) and eventually central scotoma
Mx of wet MD
Anti-VEGF injections
DDx of sudden visual loss
vascular - occlusions of vein/artery
Inflammatory - optic neuritis (MS)
Retinal detachment
presentation of retinal artery occlusion ? Key single thing O/E
Sudden, total loss of vision (central retinal artery)
or sudden latitudinal (top half or bottom half) loss (branch retinal artery)
RAPD - swinging flashlight
Name 3 Ix in retinal emboli
Carotid artery doppler
fasting serum lipids
\+/- ECG (+ ECHO if young and calcific embolus) FBC EST CT head Clotting screen
What is amaurosis fungax
Loss of vision for 30 mins (ocular TIA)
Exam q
Cherry red spot at fovea + retinal oedema
Why do you see the cherry red spot?
central retinal artery occlusion
The cherry red spot is seen because the layer of retina is thinnest at the fovea, so when this layer starts to die you can see the dense vascular choroidal vessels below which appears red.
What is ocular ischaemic syndrome?
What is the presentation?
Name 3 signs of ocular ischaemic syndrome
It is a chronic condition affecting the anterior and posterior compartments of the eye as well as other structures supplied by the ophthalmic artery. It may occur due to due to hypoperfusion as a result of carotid stenosis.
Presentation:
- gradual or sudden visual loss
Signs:
Anterior signs:
- Rubeosis (abnormal vessel growth on iris)
- Dilated episcleral vessels
- Corneal oedema
Posterior signs:
- Blot haemorrhages (peripheral/midperipheral)
- Microaneurysms
- Dilated veins
What Ix do you have to do with microaneurysms and why ?
fluorescein angiography to check for perfusion and leak
microaneurysms are often watch and wait but if there it is leaking and fovea is threatened what mx? Ix?
Laser around margin
Ix
HTN, lipids, source of emboli, consider aspiirn
Name 2 things seen on opthamoscopy of branch retinal vein occlusion
Flame haemorrhages
Leaking veins
Intact arteries
What do you need to do with branch retinal vein occlusion ix?
Must establish integrity of foveal arcade!
= fluorescein angiography
1st / 2nd line mx for branch retinal vein occlusion? What is it that you are treating?
The treatment is needed to reduce macular oedema secondary to branch retinal vein occlusion.
THE NEW GUIDELINES:
- first line is anti-VEGF injections e.g. Ranibiumab. to prevent neovascularisation
- second line is modified grid laser photocoagulation
How do you identify retinal non perfusion
RAPD
Extensive blots and microinfarcts
Fluorescein angiography
name 2 things seen on ophthalmoscopy of central retinal vein occlusion?
Widespread flame haemorrhages
swollen optic disc
dilated tortuous veins
extensive blot haemorrhages worse centrally
macular oedema - this is what we are treating because it leads to blindness!!!
mx of central retinal vein occlusion
Anti-VEGF injections e.g. Ranibizimab
What is rubeosis? Mx/
new vessles forming on iris
Immediate AGGRESSIVE PRP (panretinal photocoagulation) +/- vitrectomy
What is AION?
Usual association with Anterior ischaemic optic neuropathy
It is sudden visual loss due to disruption of the blood supply to the head of the optic nerve.
GCA - this arteritis reduces blood supply to the optic nerve
Optic neuritis key assoc?
MS
Usual cause of retinal detachement? what happens? what does it lead to?
Name 2 sx
When can these symptoms be normal?
Retinal tear
Potential space between photoreceptors and RPE fills with fluid
Retina lifted or detached which leads to a field defect.
flashes -> retinal traction
floaters -> vitreous haemorrhage
field loss -> detached retina
Flashes and floaters can occur with age as your vitreous volume shrinks. This leads to posterior vitreous detachment which doesn’t cause problems in most people.
Mx of retinal detachment
Surgery
What is hypersensitive retinopathy? Name 3 features of hypertenisive retinopathy
Management?
HR = HTN leading to damage of the retinal blood vessels.
Arteriolar changes = Arteriovenous crossing change (nipping) - vein disappears under artery as arterial wall is thickened, atherosclerosis of arteries, Heightened reflex on artery (silver wiring)
Advanced changes = Microinfarcts (cotton wool spots), Flame haemorrhages
Mx = manage BP!
Name 2 comps of hypertensive retinopathy
Retinal vein occlusion (B/C) (due to compression from atherosclerotic arteries)
Retinal artery occlusion (due to atherosclerosis)
AION - Anterior ischemic optic neuropathy
Exacerbation of diabetic retinopathy
Retinal macroaneurysms
Whats the issue with dropping BP too quick in accelerated hypertension
may lead to ischaemic optic neuropathy and blindness
2 parts of diabetic retinopathy causing damage?
microvascular leakage
occlusion
stages getting worse of diabetic retiopathy and features of each
Background - balloon-like swellings are growing (micro aneurysms) on the retinal vessels.
- Dots, blots (<3), hard exudates
Pre-proliferative - the vessels nourishing the retina swell and can become blocked, encouraging the formation of new vessels via VEGF
- Cotton wool spots (ischaemic nerve fibres), blots 4+, venous beading
Proliferative - VEGF being released to create new blood vessels but these are immature only with a lamina propria so they leak more and more!
Neovascularisation - vitreous haemorrhage
Dots and blots are ruptured microaneurysms in the retinal layer!
Visual loss in diabetic retinopathy
PATCHY VISUAL LOSS (like cow spots)