Visual Loss + Blindness

Question 1

Define swollen optic disc vs papilloedema

Answer 1

‘Swollen optic discs’ means disc swelling secondary to ANY cause
‘Papilloedema’ is a specific term meaning swollen optic discs secondary to raised intracranial pressure (ICP).

Question 2

What should you suspect in bilateral optic disk swelling?

Answer 2

All patients with bilateral optic disc swelling should be suspected of having raised ICP due to a space occupying lesion (SOL) until proven otherwise.
Raised ICP is a medical emergency.

Question 3

Give five things that CN II examination should include

Answer 3

• Visual acuity
• Pupil exam
• Visual field assessment
• Colour vision

Question 4

Describe the pathophysiology of papilloedema

Answer 4

• Subarachnoid space (SAS) around optic nerve (ON) continuous with subarachnoid space surrounding the brain.
• When intracranial pressure increases, this is transmitted to the SAS then to the ON…..
• This causes interruption of axoplasmic flow and venous congestion = swollen discs.

Question 5

Intracranial pressure is the sum of which three components?

Answer 5

1. Brain – 80%
2. Blood – 10%
3. CSF – 10%

Question 6

How does raised ICP kill?

Answer 6

With raised ICP, brain is squeezed through foramen magnum, brainstem compressed, patient stops breathing and dies.

Question 7

Give one cardio investigation you should always do in a patient with raised ICP?

Answer 7

Blood pressure

Question 8

What is the function of the choroid plexus?

Answer 8

A network of capillaries which filter blood to form CSF

Question 9

25 yo female with 6 month history of headaches, BMI 40, VA 6/6 R & L.
Lumbar puncture showed raised CSF opening pressure.
Diagnosis?
- Mechanism of swelling?

Answer 9

Idiopathic intracranial hypertension
Various theories relating to
- Obstruction to CSF circulation
- Impaired CSF absorption

Question 10

What happens if disc swelling of any cause becomes chronic?

Answer 10

Disc swelling subsides, discs become atrophic and pale.

Loss of visual function occurs and blindness may result.

Question 11

Give six causes of sudden visual loss

Answer 11

1. Vascular aetiology
2. Retinal detachment
3. Age related macular degeneration (ARMD) - wet type
4. Closed angle glaucoma
5. Optic neuritis
6. Stroke

Question 12

Which artery gives branches to supply the eye?

What is this artery a branch of?

Answer 12

Ophthalmic artery

Internal carotid artery

Question 13

Name two arteries that the ophthalmic artery gives off

Answer 13

Central retinal artery

Posterior ciliary arteries either side

Question 14

Describe the arterial blood supply to the retina

Answer 14

Inner 2/3 retina supplied by central retinal artery branches
Outer 1/3 of retina supplied by posterior ciliary arteries

Question 15

Give four vascular aetiologies of sudden visual loss

Answer 15

Occlusion of 
- Retinal circulation 
- Optic nerve head circulation
Haemorrhage from  
- Abnormal blood vessels (e.g. diabetes, wet ARMD)
- Retinal tear

Question 16

Describe the symptoms of central retinal artery occlusion and the appearance on funsoscopy

Answer 16

• Sudden visual loss
• Profound (CF or less- remember CRA is ‘end artery’)
• Painless
  On fundoscopy the retina looks very pale - the orange bit is actually healthy retina
  Also thread like retinal vessels

Question 17

What is myosis?

Answer 17

Constriction of pupils

Question 18

What happens to the pupil in central retinal artery occlusion?

Answer 18

Relative afferent pupil defect (RAPD)
As you swing light from one side to the other, the abnormal pupil dilates due to less contriction of the sphincter pupillae

Question 19

Give two general causes of CRAO

Answer 19

1. Carotid artery disease

2. Emboli from the heart (unusual)

Question 20

Name two variants of central retinal vein occlusion

Answer 20

1. Branch retinal artery occlusion

2. Amaurosis fugax

Question 21

Describe the appearance of superior retinal artery occlusion on fundoscopy
What will visual loss be like?
Where will the visual field defect be?

Answer 21

Paler bit superior to macula – can see that the artery looks thinner compared to the vein.
Visual loss may not be as profound.
Will have a visual field defect at the bottom of their vision.

Question 22

What is the other name for Transient CRAO?
What happens in the condition?
What is the characteristic symptoms in this condition?

Answer 22

Amaurosis fugax
Central retinal artery is blocked and then becomes released
Patients describe a curtain/dark shutter coming down – very characteristic for this condition.
This lasts~5mins with full recovery

Question 23

Which clinic should patients with transient CRAO be referred to?

Answer 23

TIA - do this immediately

Also give aspirin if no contraindications

Question 24

Name another cause of transient visual loss

What other main symptom does this condition have?

Answer 24

Migraine – visual loss usually followed by headache. This is an important differential to keep in mind when considering amaurosis fugax.

Question 25

Give four causes of CRVO

Answer 25

Atherosclerosis Hypertension Hyperviscosity Raised IOP (venous stasis)

Question 26

Give some symptoms and signs of CRVO | Treatment?

Answer 26

``` Sudden visual loss - moderate to severe Retinal haemorrhages Dilated tortuous veins Disc and macular swelling Looks like a "horrific pizza" ```

Question 27

Treatment of CRVO?

Answer 27

- Based on cause - Monitor: may develop complications due to development of new vessels (laser treatment may be required to avoid complications from these vessels e.g. vitreous haemorrhage) - anti-VGEF - chemicals which you inject into the vitreous cavity to stop new vessels budding

Question 28

What other type of vein occlusion should you keep a look out for?

Answer 28

Branch veins occlusion - only a sector of the retina is affected, but similar things are observed in the affected area - haemorrhage, cotton wool spots.

Question 29

``` What is ischaemic optic neuropathy? Which arteries become occluded? What are the two types? What symptom do both types cause? How does the disc appear? ```

Answer 29

Occlusion of optic nerve head circulation Posterior ciliary arteries (PCA) become occluded, resulting in infarction of the optic nerve head 1. Arteritic 50% - inflammation (GCA) – in tiny vessels such that is blocks off the artery 2. Non-arteritic 50% - atherosclerosis Both cause sudden, profound visual loss with swollen disc. Disc appears pale and swollen

Question 30

Describe the pathogenesis of arteritic ION

Answer 30

- Giant cell arteritis (GCA) - Medium to large sized arteries inflamed (multinucleate giant cells) - Lumen of artery becomes occluded (posterior ciliary arteries) - Visual loss from ischaemia of optic nerve head - Image opposite is temporal artery – grossly thickened with inflammation + v narrow lumen

Question 31

What symptoms does arteritic ION caused by GCA cause? | How can you prevent visual loss in the other eye?

Answer 31

- Sudden visual loss - Profound (CF – NPoL) - Irreversible blindness - Important as diagnosis and immediate treatment may prevent bilateral visual loss Immediate high dose systemic steroid may prevent other eye going blind.

Question 32

Describe the symptoms of GCA

Answer 32

- Headache (usually temporal) - Jaw claudication - Scalp tenderness (painful to comb hair) - Tender/enlarged scalp arteries - Amaurosis fugax - Malaise - Very High ESR , PV and CRP - Temporal artery biopsy may help diagnosis

Question 33

Where in the eye does haemorrhage commonly occur? | Where does the bleeding come from?

Answer 33

Vitreous cavity - "vitreous haemorrhage" Bleeding occurs from abnormal vessels - associated with retinal ischaemia and new vessel formation e.g. after retinal vein occlusion or diabetic retinopathy. Bleeding occurs from normal retinal vessels - usually associated with a retinal tear.

Question 34

Vitreous haemorrhage - Symptoms? - Signs? - Management?

Answer 34

``` Symptoms - Loss of vision - ‘Floaters’ Signs - Loss of red reflex - May see haemorrhage on fundoscopy Management - Identify cause - Vitrectomy for non-resolving cases ```

Question 35

Retinal detachment - Symptoms? - Signs? - Management?

Answer 35

``` Symptoms - Painless loss of vision - Sudden onset of flashes/floaters (mechanical separation of sensory retina from retinal pigment epithelium) – pigment cells are liberated and dispersed into vitreous cavity Signs - May have RAPD - May see tear on ophthalmoscopy Management is usually surgical ```

Question 36

What are the two types of age related macular degeneration?

Answer 36

- Dry (gradual reduction in vision) | - Wet (sudden reduction in vision)

Question 37

What are the three layers at the back of the eye?

Answer 37

1. Retinal layer 2. Retinal pigment epithelium - has a variety of functions which keep the retinal healthy 3. Choroid plexus - rich vascular network from posterior ciliary arteries

Question 38

What is the pathology in wet macular degeneration? Symptoms + signs? Treatment?

Answer 38

Basically New blood vessels grow under retina – leakage causes build up of fluid/blood and eventually scarring. - Rapid central visual loss - Distortion (metamorphopsia) or patches of visual loss - Haemorrhage/exudate Anti-VEGF treatment – injected into vitreous cavity. Stops new blood vessels growing by binding to VEGF (vascular endothelial growth factor).

Question 39

What is the pnemonic for gradual loss of vision?

Answer 39

CARDIGAN - Cataract - Age related macular degeneration (dry type) - Refractive error - Diabetic retinopathy (covered in other lecture) - Inherited diseases e.g. retinitis pigmentosa - Glaucoma Access (to eye clinic) Non-urgent

Question 40

Management of cataract?

Answer 40

Management is surgical removal with intra-ocular lens implant if patient is symptomatic. Two small surgical incisions – put in a vibrating thing which mushes up the cataract and sucks it out.

Question 41

Dry age related macular degeneration - Pathology? - Aetiology? - Symptoms? - Signs? - Treatment?

Answer 41

Photoreceptors have constant turnover – waste products build up and form Drusen (white dots) – causes pigment epithelial cells to be lifted off the choroid -> retina becomes atrophic and thinned. Multifactorial condition – age, genetics, UV exposure, dietary things. - Gradual decline in vision - Central vision ‘missing’ (scotoma) - Drusen – build up of waste products below RPE - Atrophic patches of retina No cure – treatment is supportive with low vision aids e.g. magnifiers – shown opposite.

Question 42

What is the defining feature in glaucoma?

Answer 42

Progressive optic neuropathy

Question 43

Describe the symptoms and treatment of closed angle glaucoma

Answer 43

- May be acute (ophthalmic emergency) - Patient presents with painful, red eye/visual loss/headache/nausea/vomiting - Need to lower IOP with drops/oral medication to prevent patient going blind - Emergency

Question 44

Closed angle glaucoma - Symptoms? - Signs? - Treatment?

Answer 44

``` Symptoms - Often NONE - Optician may discover it Signs - Cupped disc - Visual field defect - May/may not have high IOP Treatment – aim to preserve vision (by lowering IOP) with eye drops /laser/surgery. Patients need regular monitoring in eye clinic. ```