Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ophthalmology > Diabetic Retinopathy > Flashcards

Diabetic Retinopathy Flashcards

1
Q

Diabetic retinopathy is the most common cause of blindness in what age group?

A

Adults aged 35-65

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What percentage have ocular problems when diabetes presents?

A

30% , but the majority remain asymptomatic until advance disease takes hold (at which point little can be done)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the pathogenesis

A

Microangiopathy in capillaries causes:
1) vascular occlusion leading to ischaemia +/- new vessel formation (which bleed). Ischaemia causes cotton wool spots

2) vascular leakage as pericytes are lost - capillaries bulge (micro aneurysms) and there is oedema and hard exudates. Rupture of micro aneurysms can cause flame shaped haemorrhages or blot haemorrhages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are cotton wool spots?

A

Ischaemic nerve fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the impact of hyperglycaemia?

A

Increased retinal blood flow and abnormal metabolism in retinal vessel walls - damage to endothelial cells and pericytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does endothelial dysfunction lead to?

A

Increased vascular permeability - causes the characteristic exudates seen on fundoscopy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does pericyte dysfunction predispose?

A

Micro aneurysms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is neovasculisation thought to be caused by?

A

Production of growth factors in response to ischaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are hard exudates comprised of?

A

Lipoprotein and lipid filled macrophages. It has leaked from abnormal retinal capillaries, so often associated retinal oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two types of diabetic retinopathy?

A

Non-proliferative diabetic retinopathy

Proliferative diabetic retinopathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is NPDR rated?

A

Mild
Moderate
Severe

Depending on degree of ischaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe mild NPDR

A

1 or more micro aneurysms (small red dots often in clusters), do not affect vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe moderate NPDR

A

Micro aneurysms
Blot haemorrhages
Hard exudates
Cotton wool spots, venous beading/ looping and intraretinal microvascular abnormalities less severe than in severe NPDR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe severe NPDR

A

Blot haemorrhages and micro aneurysms in 4 quadrants
Venous bleeding in at least 2 quadrants
Itraretinal microvascular abnormalities at least 1 quadrant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe proliferative diabetic retinopathy

A

Fine new vessels appear on optic disc, retina and can cause vitreous haemorrhage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is maculopathy?

A

When macula is affected by retinopathy

Leakage of vessels close to macula can cause macula oedema - can significantly threaten vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Who should be referred urgently for assessment and treatment?

A

Those with:
Maculopathy
Severe NPDR
PDR

18
Q

How can DM cause glaucoma?

A

DM causes ocular ischaemia, which can cause new blood vessels to form on the iris - these can block the drainage of aqueous fluid

19
Q

The formation of age related cataracts is accelerated in DM. True or false?

A

True

20
Q

How often should those with DM type 1 and 2 have their eyes screened?

A

At time of diagnosis and then at least annually

21
Q

Screening is done by…

A

Dilated fundus photography - referrals then made accordingly
Lesions mostly at posterior pole and can be seen by ophthalmoscope

22
Q

Proliferative retinopathy heightens the risk of…

A

Retinal detachment

Fibrosis and connective tissue develops - asserts traction

23
Q

What do micro aneurysms look like?

A

Small red dots often in clusters

24
Q

What are the earliest clinically visible changes of diabetic retinopathy?

A

Micro aneurysms

25
Q

Do micro aneurysms affect vision?

A

No

26
Q

Intraretinal haemorrhages may be dot, blot or flame depending on…

A

Their depth within the retina
The capillary layer in the posterior retina has 2 layers - superficial in nerve fibre layer and deeper on within nuclear layer. Haemorrhages within nerve fibre layer = flame shaped, inner layer haemorrhages = dot or blot

27
Q

The hard exudates (intra retinal deposits) can vary from small specks to large patches and may evolve into rings known as…

A

Circinates

28
Q

Where are the hard exudates principally found?

A

Macular region and as the extend into fovea, vision can be severely compromised

29
Q

What do cotton wool spots look like?

A

Greyish white patches in the nerve fibre layer which has fluffy edges.

30
Q

What are intraretinal microvascular abnormalities?

A

Areas of capillary dilatation and intraretinal new vessel formation. Arise within ischaemic retina

31
Q

When neovascularisation occurs, where are the new vessels usually found?

A

Initially seen as fine tufts on surface of the disc

Large veins

32
Q

What is a sub-hyaloid haemorrhage?

A

New vessels form abnormal adhesions with vitreous. Where there is areas of detachment of vitreous, blood can accumulate between retina and vitreous = sub hyaloid haemorrhage

33
Q

What is used to treat maculopathy and proliferative retinopathy?

A

Photocoagulation
Trans pupillary laser applied so as to produce a retinal burn - used to treat the new blood vessels
It does not improve vision, it is intended to prevent blindness

34
Q

What can accelerate retinopathy?

A 
Pregnancy
Hypertension 
Renal disease
Dyslipidaemia 
Smoking
Anaemia
35
Q

What is used to treat macula oedema?

A

Intravitreal triamcinolone and anti VEGF drugs

Focal laser treatment to seal any leaking micro aneurysms

36
Q

What can reduce the risk of visual deterioration in patients with diabetic macula oedema by at least 50% ?

A

Grid laser therapy

37
Q

What are some side effects of laser treatment?

A

Loss of peripheral vision, colour vision, night vision

38
Q

How can diabetic retinopathy be prevented?

A

Keep blood sugar levels as close to normal as possible
Control BP <140/80 or < 130/80 if end organ damage
Lower cholesterol

39
Q

What examinations can be done?

A

Slit lamp/ ophthalmoscope
Fluorescein angiography to assess damage
Optic coherence tomography to assess if any macula oedema

40
Q

What is fluorescein angiography?

A

A test to examine the back of the eye - see if there are any problems with the vessels there.
Vein injected with the yellow sodium fluorescein dye - travels round body. Retina illuminated with blue light.
Angiogram obtained by photographing the green light that is emitted.

41
Q

What symptoms occur with diabetic retinopathy?

A

Early stages usually no symptoms
Some people may notice trouble reading or seeing objects far away
In later stages - vessels start to bleed into vitreous gel - dark, floating spots or streaks that look like cobwebs
If macular oedema present: blurry vision due to extra fluid

42
Q

Why can diabetic retinopathy cause retinal detachment?

A

It can cause scars to form at back of eye

These scars can pull the retina away from the back of the eye

Ophthalmology (25 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions