Visual Loss and Blindness

Question 1

name 7 causes of sudden visual loss

Answer 1

vascular
vitreous haemorrhage
retinal detachment
age related macular degeneration (wet type)
closed angle glaucoma
optic neuritis
stroke

Question 2

what is the main blood supply to the eye?

Answer 2

branches of the ophthalmic

• posterior ciliary arteries (either side of central retinal artery)
• central retinal artery (in the middle)

Question 3

occlusion of what can cause sudden visual loss?

Answer 3

retinal circulation (retinal artery/vein)
optic nerve circulation

Question 4

haemorrhage from where can cause sudden visual loss?

Answer 4

abnormal blood vessels

normal blood vessels

Question 5

what does the central retinal artery supply?

Answer 5

2/3rds of retina

Question 6

symptoms and signs of occlusion of retinal circulation (central retinal artery)

Answer 6

sudden vision loss
painless
RAPD
pale, oedematous retina (as vessels occluded so not red)
thread like retinal vessels

Question 7

why is the macula normal in central retinal artery occlusion?

Answer 7

no ganglion cells in macula

Question 8

name 2 causes of central retinal artery occlusion (CRAO)?

Answer 8

carotid artery disease

emboli from the heart (unusual)

Question 9

name 2 further variants of CRAO

Answer 9

branch retinal artery occlusion (less severe as only a branch, problems in bottom half of vision)
amaurosis fugax

Question 10

what are the features of amaurosis fugax?

Answer 10

transient, painless visual loss
“like a curtain coming down”
lasts 5 mins with full recovery
usually nothing abnormal on examination

Question 11

management of amaurosis fugax?

Answer 11

urgent referral to stroke clinic

Question 12

virchows triad?

Answer 12

hypercoagulable blood (e.g cancer)
turbulent blood flow (e.g hypertension)
endothelial damage (e.g diabetes)

Question 13

signs and symptoms of central retinal vein occlusion?

Answer 13

sudden visual loss (severity dependent on level of ischaemia)
retinal haemorrhages
dilated, tortuous veins
disc swelling and macular swelling
can have cotton wool spots (markers of ischaemia)
can have fluid build up around macula (oedema)

Question 14

artery vs vein occlusion (colour)?

Answer 14

artery = pale
vein = dark

Question 15

what vessels supply the optic nerve?

Answer 15

posterior ciliary arteries

Question 16

what is ischaemic optic neuropathy?

Answer 16

occlusion of optic nerve head circulation

posterior ciliary arteries become occluded, resulting in infarction of the optic nerve head

Question 17

name a cause of ischaemic optic neuropathy and how this occurs?

Answer 17

giant cell arteritis
medium to large sized arteries inflamed (via multinucleate giant cells) > lumen of artery becomes occluded (posterior cilliary arteries) due to gross thickening of artery wall > visual loss from ischaemia of optic nerve head

Question 18

symptoms and signs of ischaemic optic neuropathy?

Answer 18

sudden severe visual loss
irreversible blindness
swollen optic nerve

Question 19

6 symptoms of giant cell arteritis?

Answer 19

headache (usually temporal)
jaw claudication
scalp tenderness
tender/enlarged scalp arteries
amaurosis fugax
malaise

Question 20

where does haemorrhage often occur into and what is this known as?

Answer 20

into vitreous cavity

known as vitreous haemorrhage

Question 21

how can haemorrhages occur in the eye?

Answer 21

bleeding occurs from abnormal vessels (e.g retinal ischaemia in diabetes or retinal vein occlusion causes abnormal, fragile new blood vessels to form
bleeding can occur from normal vessels (e.g vessel bridging a retinal tear)

Question 22

name 5 signs and symptoms of vitreous haemorrhage

Answer 22

loss of vision
floaters
loss of red reflex
may see haemorrhage on fundoscopy
find a cause

Question 23

4 signs and symptoms of retinal detachment?

Answer 23

painless loss of vision
sudden onset of flashes/floaters (mechanical separation of sensory retina from retinal pigment epithelium)
may have RAPD
may see tear on ophthalmoscopy

Question 24

what can cause a retinal detachment?

Answer 24

tear in retina
vitreous humour can pull on the retina causing a tear
vitreous humor (which is more liquid in older people) can go through the hole and get behind the sensory retina and separate it from the retinal pigment epithalium

Question 25

what is the most common cause of blindness in the west?

Answer 25

age related macular degeneration (ARMD)

Question 26

what are the 2 types of ARMD?

Answer 26

wet (sudden visual loss) | dry (gradual visual loss)

Question 27

risk factors for ARMD?

Answer 27

increasing age smoking family history poor nutrition

Question 28

what happens in wet ARMD?

Answer 28

new vessels start to grow from the choroid up into the retina leakage causes build up of fluid/blood and eventually scarring

Question 29

5 signs and symptoms of wet ARMD?

Answer 29

rapid central visual loss distortion (metamorphosia) = straight lines look wiggly haemorrhage/exudate swelling/raised up area on imaging (fluid build up) pale area on retina (oedema from fluid)

Question 30

what is glaucoma?

Answer 30

progressive optic neuropathy | ultimately results in optic nerve damage and therefore visual loss

Question 31

what are the 2 types of glaucoma?

Answer 31

``` open angle (angle between iris and cornea) closed angle ```

Question 32

what happens in closed angle glaucoma?

Answer 32

aqueous humour encounters increased resistance through iris/lens channel increased pressure gradient causes peripheral iris to bow forward, obstructing trabecular meshwork - pressure increases

Question 33

features of closed angle glaucoma?

Answer 33

``` acute (ophthalmic emergency) painful, red eye sudden visual loss headache nausea and vomiting cloudy cornea dilated pupil ```

Question 34

immediate management of closed angle glaucoma?

Answer 34

need to lower IOP with drops/oral medication to prevent blindness

Question 35

general presentation of gradual visual loss?

Answer 35

usually bilateral often asymmetrical may present early with reduced VA may present late with decreased field

Question 36

name 5 causes of gradual visual loss

Answer 36

``` cataract age related macular degeneration (dry) refractive error glaucoma diabetic retinopathy ```

Question 37

what is cataract?

Answer 37

cloudiness of the lens abnormal changes in lens protein (crystallina) result in their chemical and structural alteration, leading to loss of transparency

Question 38

causes of cataract?

Answer 38

``` age related congenital (intrauterine infection) traumatic metabolic (diabetes - sorbitol accumulation) drug indiced (steroids) ```

Question 39

what does a nuclear cataract looks like?

Answer 39

when beam of light is shone on cornea, shows as greenish/brown colour on lens

Question 40

what does a posterior subcapsular cataract look like?

Answer 40

separate distinct beam of light in lens??

Question 41

Christmas tree cataract?

Answer 41

crystals in the lens are visible | look like Christmas tree lights

Question 42

name 2 symptoms of cataracts

Answer 42

gradual decline in vision (hazy/blurred) that cannot be corrected by glasses may get glare

Question 43

management of cataract?

Answer 43

surgical removal with intra-ocular lens implant if patient is symptomatic

Question 44

what happens in dry ARMD?

Answer 44

accumulation of drusen (metabolic by products of pigment epithelium) drusen builds up and separates the retina from the vascular supply in the choroid, which can lead to ischaemia etc?

Question 45

4 signs and symptoms of dry ARMD?

Answer 45

gradual decline in vision central vision missing (scotoma) drusen build up below retinal pigment epithelium atrophic patches on retina

Question 46

how is dry ARMD managed?

Answer 46

no cure | supportive treatment

Question 47

what happens in refractive error?

Answer 47

eye cannot clearly focus image

Question 48

name 4 types of refractive error

Answer 48

myopia (short sighted) hypermetropia (long sighted) astigmatism (usually irregular corneal curvature) presbyopia (loss of accommodation with ageing)

Question 49

management of refractive error?

Answer 49

glasses

Question 50

5 symptoms and signs of open angle glaucoma?

Answer 50

``` often none optician may discover it cupped disc visual field defect may/may not have high Intra-ocular pressure ```