Medical retina

Question 1

Name some retinovascular changes in diabetes

Answer 1

loss of endothelial tight junctions
capillary basement membrane thickening
pericyte loss
microaneurysms form
acellular capillaries

Question 2

Diabetic retinopathy risk factors

Answer 2

duration of diabetes
glucose control
BP control

Question 3

How is diabetic retinopathy classified?

Answer 3

Non-proliferative diabetic retinopathy

Diabetic maculopathy (non-proliferative diabetic retinopathy in the macula)

Question 4

How can non-proliferative diabetic retinopathy be classified?

Answer 4

mild
moderate (microaneurysms, dot-blot haem, cotton wool spots, exudates)
severe (pre-proliferative) with signs of retinal ischaemia (dilated veins, large blot haems, venous bleeding, intraretinal microvascular abnormalities, cotton wool spots)

Question 5

What are patients with severe non-proliferative diabetic retinopathy at risk of?

Answer 5

retinal new vessel growth (proliferation)

Question 6

How can non-proliferative diabetic retinopathy be identified on the retina?

Answer 6

microaneurysms (1st clinical sign)
exudate (intraretinal lipid deposits)
dot haemorrhages (cannot distinguish from microaneurysms)
blot haemorrhages
cotton wool spots (axoplasmic debris from nerve-fibre layer infarcts)

Question 7

What can retinal argon laser be used to treat?

Answer 7

used to treat macular oedema ‘threatening’ the fovea and leading to loss of acuity

macular laser reduces moderate vision loss from diabetic macular oedema

Question 8

What light illuminates fluorescein?

Answer 8

blue light

Question 9

What are the 2 subtypes of proliferative diabetic retinopathy?

Answer 9

new vessels disk (NVD) - retinal new vessels from optic disc

new vessels elsewhere (NVE) - retinal new vessels away from the optic disc

Question 10

Which way do vessels grow in proliferative diabetic retinopathy?

Answer 10

forwards into the vitreous

Question 11

What are the 2 subtypes of retinal vein occlusion?

Answer 11

branch retinal vein occlusion (BRVO) - occlusion of a branch of the retinal vein as it is crossed by a retinal arteriole

central retinal vein occlusion (CRVO) - occlusion of the vein in optic nerve as it runs alongside the central retinal artery

Question 12

Symptoms of severe/ischaemic central retinal vein occlusion

Answer 12

acute onset - often in the night and noticed on waking
painless loss of vision
visual acuity reduced to between 6/60 and hand motions vision

Question 13

Retinal signs of severe/ischaemic central retinal vein occlusion

Answer 13

severe intraretinal haemorrhages throughout the retina
engorged retinal veins
disc swelling
macular oedema
cotton wool spots
RAPD present - indicating severe loss of afferent visual input

Question 14

Severe/ischaemic central retinal vein occlusion risk factors

Answer 14

ageing
hypertension
arteriosclerosis
hyperlipidaemia
prothrombotic conditions

Question 15

Mild/non-ischaemic central retinal vein occlusion symptoms

Answer 15

acute onset - often at night and noticed on waking
painless loss of vision
visual acuity reduced to between 6/12 and 6/36

Question 16

Retinal signs of mild/non-ischaemic central retinal vein occlusion

Answer 16

mild to moderate intraretinal haemorrhages throughout the retina
engorged retinal veins
disc swelling
macular oedema
no RAPD - indicates maintained afferent visual input

Question 17

How is central retinal vein obstruction treated?

Answer 17

repeated intravitreal anti-VEGF antibody injections

this can resolve macular oedema, improving visual acuity

Question 18

Name 2 anti-VEGF drugs

Answer 18

Lucentis (ranibizumab)
Eylea (aflibercept)

Question 19

What is rubeotic glaucoma?

Answer 19

peripheral retinal ischaemia leads to growth factor production (VEGF)
VEGF diffuses through the eye and stimulates growth of new blood vessels (rubeosis) on the iris and in the drainage angle - this can narrow the angle and cause glaucoma

Question 20

Symptoms of branch retinal vein occlusion

Answer 20

acute onset - often occurs in night and noticed on waking
painless loss of vision
visual acuity reduced to between 6/9 and hand motions vision - may be asymptomatic if fovea not affected

Question 21

Retinal signs of branch retinal vein occlusion

Answer 21

intraretinal haemorrhages in area of affected vein branch only
engorged branch retinal vein
macular oedema
cotton wool spots
no RAPD - smaller area of retina involved than CRVO

Question 22

Retinal signs of hypertensive retinopathy

Answer 22

thickened arteriole wall - increased central light reflex (silver wiring)

narrowed/straightened arterioles

AV crossing changes - arteriovenous nipping

BRVO occurs at AV crossings

Question 23

What is the leading cause of blindness in the western world?

Answer 23

age-related macular oedema

Question 24

Age-related macular degeneration risk factors

Answer 24

age
family history
smoking

Question 25

Pathogenesis of age-related macular degeneration

Answer 25

complement system regulates innate immunity to infection/stress, initiating inflammation and response to pathogens complement system dysregulation can lead to chronic inflammation when complement system becomes chronically active in the eye, it can mediate damage to the choroid, RPE and photoreceptors, causing localised inflammation and cell death

Question 26

How can the retina and other structures be visualised to see their thickness and any oedema?

Answer 26

optical coherence tomogram (OCT)

Question 27

What does early age-related macular degeneration look like on the retina?

Answer 27

drusen deposits of shed photoreceptor material retinal pigment epithelium atrophy

Question 28

What does late age-related macular degeneration cause?

Answer 28

progressive central vision loss

Question 29

What are the 2 types of late age-related macular degeneration?

Answer 29

wet AMD = vascular dry AMD = atrophic

Question 30

Describe late wet AMD

Answer 30

choroidal new vessels grow under the retinal pigment epithelium (RPE) or retina and leak plasma causing sub-retinal fluid and retinal oedema haemorrhage, fibrosis and exudate can occur process driven by VEGF

Question 31

How is wet AMD treated?

Answer 31

anti-VEGF monoclonal antibody intravitreal injections

Question 32

What does end-stage we AMD disease look like on the retina?

Answer 32

pigment clumping sub-retinal fibrosis

Question 33

Describe what causes late dry AMD

Answer 33

thickening of retinal pigment epithelium basement membrane (Bruch's membrane) and sclerosis of choroidal vessels associated with progressive atrophy leads to patches of loss of choroid/RPE/retina in an irregular shape (geographic atrophy) these patches enlarge, causing scotoma and visual acuity loss of fovea affected

Question 34

Is dry AMD treatable?

Answer 34

no slowly progressive vision loss over months to years

Question 35

What does amaurosis fugax do to vision?

Answer 35

transient and sudden monocular blindness curtain that obscures vision in one eye

Question 36

What can cause amaurosis fugax?

Answer 36

carotid atheroma - (fibrin-platelet or cholesterol emboli) cardiac valves (calcific emboli)

Question 37

What causes central retinal artery occlusion?

Answer 37

carotid atheroma is main cause - cholesterol or fibrin-platelet emboli cardiac calcified aortic and mitral valvular lesions can be due to giant cell arteritis

Question 38

Examination signs of central retinal artery occlusion

Answer 38

retinal whitening due to infarcted swollen inner 2/3 retina supplied by central retinal artery cherry-red spot due to no inner retina covering fovea centre retinal infarction causes late optic atrophy (pale optic disc) and retinal artery narrowing

Question 39

What causes the visual symptoms of GCA?

Answer 39

ischaemic optic neuropathy