Visual loss and blindness

Question 1

What are the 7 causes of sudden visual loss?

Answer 1

1. Vascular aetiology (retinal artery/vein occlusion)
2. Vitreous haemorrhage
3. Retinal detachment
4. Wet ARMD
5. Closed angle glaucoma
6. optic neuritis
7. Stroke

Question 2

Describe the arterial supply of the eye

Answer 2

Internal carotid artery gives off branches, ophthalmic artery is the main supply to the eye

Question 3

What are the branches of the ophthalmic artery?

Answer 3

Posterior ciliary, supply the optic nerve head

Central retinal artery, supply inner 2/3rds of retina

Question 4

What are the symptoms of central retinal artery/vein occlusion ?

Answer 4

Sudden visual loss

Painless

Question 5

What are the signs of central retinal artery occlusion?

Answer 5

RAPD

Pale oedematous retina

Thready retinal vessels

Question 6

Describe branch retinal artery occlusion

Answer 6

Only part of retina will look pale

Half of visual field compromised

Question 7

Describe amaurosis fugax symptoms?

Answer 7

Transient painless visual loss

Lasts 5 minutes with full recovery

Question 8

When can haemorrhages occur in the eye?

Answer 8

Abnormal blood vessels- wet ARMD, diabetes

Normal vessels -Bridging a retinal tear

Question 9

What are the causes of central retinal vein occlusion?

Answer 9

Carotid artery disease

Emboli from heart- endocarditis?

Question 10

What are the signs of a central retinal vein occlusion?

Answer 10

• retinal haemorrhages
• dilated torturous veins
• disc swelling and macular swelling
• edge of disc may be swollen
• cotton wool spots
• oedematous macula

Question 11

What is ischaemic optic neuropathy?

Answer 11

Posterior ciliary arteries become occluded, infarction of optic nerve head

Question 12

What can cause ischaemic optic neuropathy?

Answer 12

GCA

Question 13

What are the symptoms of ischaemic optic neuropathy?

Answer 13

Sudden visual loss

Irreversible blindness

Question 14

What are the signs of ischamic optic neuropathy?

Answer 14

Swollen optic nerve

Question 15

Describe symptoms of a vitreous haemorrhage

Answer 15

Loss of vision

Floaters- flu, cobwebs, black dot

Question 16

What are the signs of a vitreous haemorrhage?

Answer 16

Loss of red reflex
-media not clear, may look black, brown

May see haemorrhage on fundoscopy

Question 17

What is important in vitreous haemorrhage?

Answer 17

Fina a cause

Question 18

What are the symptoms of retinal detachment?

Answer 18

Painless loss of vision

Sudden onset of flashes/floaters (mechanical separation of sensory retina from retinal pigment epithelium)

Question 19

What are the signs of retinal detachment?

Answer 19

RAPD

Question 20

What can cause retinal detachment?

Answer 20

Age makes vitreous more liquidy- this can pull on retina and tear it

Question 21

What are the factors related to ARMD?

Answer 21

Smoking, FHx, poor nutrition

Question 22

Describe wet ARMD?

Answer 22

New blood vessels grow under retina from the choroid, leakage causes build up of fluid/blood and eventually scarring

Question 23

What are the symptoms of wet ARMD?

Answer 23

Rapid central visual loss

Distortion (metamorphosia- straight lines may appear linked)

Question 24

What are the signs of wet ARMD?

Answer 24

Haemorrhages/exudate (protein leaked and precipitated into retina)

Question 25

What is the amsler test?

Answer 25

Grid- cover up one eye and describe what you see

Question 26

What are the symptoms of dry ARMD?

Answer 26

Gradual visual loss

Question 27

What is the only modifiable risk factor in glaucoma?

Answer 27

High IOP

Question 28

Describe closed angle glaucoma?

Answer 28

- aqueous humour encounters increased resistance through iris/lens channel - increased pressure gradient causes peripheral iris to bow forward, obstructing trabecular meshwork- pressure increases - may be acute (ophthalmic emergency)

Question 29

Describe the symptoms of acute closed angle glaucoma?

Answer 29

Painful, red eye/sudden visual loss/headache/nausea/vomitting

Question 30

Describe the signs of acute closed angle glaucoma?

Answer 30

Red eye, cloudy cornea, dilated pupil

Question 31

What causes pupil dilation in acute closed angle glaucoma?

Answer 31

Ischaemia has rendered it non-functional

Question 32

What are the common causes of gradual visual loss?

Answer 32

``` Cataracts Dry ARMD Refractive error Open angle glaucoma Diabetic retinopathy ```

Question 33

Describe cataracts?

Answer 33

Cloudiness of the lens- abnormal changes in lens proteins (crystalline) result in their chemical and structural alteration, leading to loss of transparency

Question 34

What are the causes of cataracts?

Answer 34

``` Age Congenital e.g. Intra-uterine infection Traumatic Metabolic (diabetes) Drug induced ```

Question 35

What are the 4 types of cataract?

Answer 35

Nuclear cataract Posterior subcapsular cataract Polychromatic cataract Congenital cataract

Question 36

Which type of cataract is particularly visually disabling?

Answer 36

Posterior sub capsular cataract

Question 37

Describe a congenital cataract?

Answer 37

Dense centre- no brown/green colour

Question 38

What are the symptoms of cataract?

Answer 38

Gradual decline in vision (hazy/blurred) that cannot be corrected Glare (at night when driving)

Question 39

Describe dry ARMD?

Answer 39

Build up of drusen inner retina (by-products of epithelial cells) stops nutrition diffusing to retina from choroid. The retina gets further away from nutrition and thins

Question 40

What are the symptoms of dry ARMD?

Answer 40

Gradual decline in vision Central vision missing (scotoma)

Question 41

What are the signs of dry ARMD?

Answer 41

Drusen= yellow-white flecks Atrophic bathes of retina (appears bright red as you can see choroidal vessels)

Question 42

What is myopia?

Answer 42

Short-sightedness

Question 43

What is hypermetropia?

Answer 43

Long-sightedness

Question 44

What is astigmatism?

Answer 44

Irregular corneal curvature

Question 45

What is presbyopia?

Answer 45

loss of accommodation with ageing

Question 46

Describe open angle glaucoma?

Answer 46

Something stopping drainage through trabecular meshwork

Question 47

What are the signs of closed angle glaucoma?

Answer 47

Cupped disc Visual field defect (Arcuate) May/may not have high IOP