5: Visual loss and blindness Flashcards by Ross Wilson

What is the major artery supplying the eye?

Which artery in the neck does it stem from?

Ophthalmic artery

Internal carotid artery

How well did you know this?

Not at all

Perfectly

What are the important branches of the ophthalmic artery which you should know?

Central retinal artery (inner 2/3rds of retina)

Posterior ciliary arteries (optic nerve head)

How well did you know this?

Not at all

Perfectly

Which structure supplies the other 1/3rd of the retina?

Choroid

How well did you know this?

Not at all

Perfectly

What vascular problems cause sudden visual loss?

Occlusion

Haemorrhage

How well did you know this?

Not at all

Perfectly

Which artery supplies the inner 2/3rds of the retina?

Central retinal artery

How well did you know this?

Not at all

Perfectly

What are the symptoms of central retinal artery occlusion?

Sudden profound vision loss

Which is painless

How well did you know this?

Not at all

Perfectly

What reflex is disrupted in CRAO?

Pupillary light reflex

pupil doesn’t constrict in response to light - relative afferent pupil defect (go back and forth fast enough and the pupil will actually dilate in response to light)

because optic nerve is infarcted

How well did you know this?

Not at all

Perfectly

What does the retina look like in a central retinal artery occlusion?

Pale

Cherry spot fovea

Arteries either absent or blocked

How well did you know this?

Not at all

Perfectly

Central retinal artery occusion is a type of ___.

stroke

How well did you know this?

Not at all

Perfectly

What causes central retinal artery occlusion?

Carotid artery disease

How well did you know this?

Not at all

Perfectly

How are central retinal artery occlusions managed?

Ocular massage (attempt to convert to branch occlusion)

Manage risk factors

How well did you know this?

Not at all

Perfectly

What is amaurosis fugax?

Transient central artery occlusion

How well did you know this?

Not at all

Perfectly

What are the symptoms of amaurosis fugax?

Transient painless visual loss

lasting 5 mins with full recovery

How well did you know this?

Not at all

Perfectly

How is amaurosis fugax treated?

Aspirin (anti-platelet)

Urgent referral to stroke clinic

How well did you know this?

Not at all

Perfectly

What is Virchow’s triad?

Endothelial injury

Hypercoagulability

Stasis / turbulent blood flow

How well did you know this?

Not at all

Perfectly

What are the symptoms of central retinal vein occlusion?

Sudden painless visual loss

How well did you know this?

Not at all

Perfectly

CRVO is associated with a raised ___ pressure.

intraocular

How well did you know this?

Not at all

Perfectly

What are the signs of CRVO on fundoscopy?

Haemorrhages - inc. cotton wool spots

Dilated torturous veins

Optic disc and macular swelling

How well did you know this?

Not at all

Perfectly

What type of scan is used to pick up macular oedema?

OCT scan

How well did you know this?

Not at all

Perfectly

How is CRVO treated?

Laser treatment

Anti-VEGF injections (VEGF released in response to ischaemia, encourages development of poorly structured blood vessels which haemorrhage)

Address risk factors

How well did you know this?

Not at all

Perfectly

What processes drive

a) arterial
b) venous

occlusions of the eye?

a) Internal carotid disease

b) Venous stasis

How well did you know this?

Not at all

Perfectly

Which arteries supply the optic nerve head?

Posterior ciliary arteries

How well did you know this?

Not at all

Perfectly

What is occlusion of the posterior ciliary arteries also known as?

Ischaemic optic neuropathy

How well did you know this?

Not at all

Perfectly

What tends to cause arterial ischaemic optic neuropathy?

Giant cell arteritis

How well did you know this?

Not at all

Perfectly

What causes **non-arteritic ischaemic optic neuropathy**?

**Atherosclerosis**

What does the optic disc look like in ischaemic optic neuropathy?

**Swollen**

What is the main symptom of **arteritic** **ischaemic optic neuropathy?**

**Sudden irreversible visual loss**

Irreversible blindness is an end-stage symptom of giant cell arteritis. What are the other symptoms?

**Headache** **Jaw claudication** **Scalp tenderness** **Tender, enlarged temporal arteries** **Transient arterial occlusions (amaurosis fugax)** **Malaise** **Raised inflammatory markers**

How is giant cell arteritis treated to prevent immediate bilateral blindness?

**High dose oral prednisolone**

Where in the eye does bleeding tend to occur?

**Vitreous cavity**

What is a bleed into the vitreous cavity called?

**Vitreous haemorrhage**

What are the symptoms of **vitreous haemorrhage**?

**Loss of vision** **Floaters**

What are signs of vitreous haemorrhage on fundoscopy?

**Loss of red reflex** **Clear haemorrhage**

How is vitreous haemorrhage managed?

**Management of underlying disease** **Vitrectomy**

What are the symptoms of **retinal detachment**?

**GRADUAL painless loss of vision** **Flashes** **Floaters**

What is the commonest cause of blindness in elderly people?

**Age-related macular degeneration (ARMD)**

What are the two types of ARMD?

**Wet** (sudden) **Dry** (gradual)

What causes **wet ARMD**?

**New blood vessels grow in choroid, causing fluid bulge and scarring**

What are the symptoms of **wet ARMD?**

**Rapid CENTRAL vision loss** **Metamorphopsia** - visual distortion

How is **wet ARMD** treated?

**Anti-VEGF injections**

What is the jist of glaucoma?

**Damage to optic nerve**

What are two different types of glaucoma?

**Open-angle** **Closed-angle**

Where does aqueous fluid drain?

**Canal of Schlemm** (trabecular meshwork) at **iridocorneal angle**

What causes closed-angle glaucoma?

**Blockage of trabecular network by bulging iris causes increased IOP**

What are the symptoms of closed angle glaucoma?

**Painful, red eye** **Sudden peripheral visual loss** **Headache, nausea, vomiting**

How is closed angle glaucoma treated?

**Lower IOP with drops** - carbonic anhydrase, beta blockers etc. **Laser iridotomy** - trabeculectomy???

What are some causes of **gradual visual loss**?

**Cataracts** **Dry ARMD** **Refractive error** **Glaucoma** **Diabetic retinopathy**

What are **cataracts**?

**Cloudiness of the lens**

Which drugs can induce cataracts?

**Steroids**

When would cataracts be managed? How?

**If symptomatic** **Surgical lens implant**

**Dry** ARMD causes **(sudden / gradual)** visual loss.

**gradual visual loss**

ARMD causes (**central / peripheral**) vision loss.

**central vision loss**

What causes dry ARMD?

**Build-up of DRUSEN - waste products below retina** Causes retina to tent away from choroid and become atrophic

How is **dry ARMD** treated?

**Supportively** - magnifiers, care etc.

What is **refractive error**?

**Eye cannot clearly focus an image**

What is **myopia**? Which type of lens is used to treat it?

**Short-sightedness** Light focused TOO EARLY, BEFORE RETINA Treated using **concave** lens **(diverges light)**

What is **hypermetropia**? Which type of lens is used to treat it?

**Long-sightedness** Light focused too LATE Treated using **convex lenses**

What is **astigmatism?**

**Irregular CORNEAL curvature**

What is **presbyopia**?

**Loss of accommodation reflex with aging**

What type of glaucoma causes **gradual visual loss** or is **asymptomatic**?

**Open-angle glaucoma**

What are the signs of **open-angle glaucoma**?

**Cupped disc** **Visual field defects** but patient may be asymptomatic

What is the cup:disc ratio like in glaucoma?

**Too big**

Where does visual loss occur first in glaucoma?

**Peripheral first**

Do patients with glaucoma have tunnel vision?

**No - they fill in the rest of the image (incorrectly)**

How is open-angle glaucoma treated?

**Drops to lower BP** **Laser treatment** **Surgery**

5: Visual loss and blindness Flashcards

(65 cards)