Diabetic Eye Disease Flashcards

1
Q

5 RFs for progression of diabetic retinopathy

A

Lack of exercise
Not getting annual eye exam
Poor BP control
Poor glycaemic control
Pregnancy

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2
Q

What is the most common cause of blindness in adults aged 35-65?

A

Diabetic retinopathy

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3
Q

Describe pathophysiology of diabetic retinopathy

A

Hyperglycaemia increases retinal blood flow
Causes blood vessels to weaken/ rupture→ micro aneurysms + small haemorrhages

Endothelial dysfunction
→ increased vascular permeability
→ hard exudates on fundoscopy.

As blood flow increasingly compromised, hypoxia stimulates release of VEGF promoting neovasculization

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4
Q

What are the broad stages of diabetic retinopathy?

A

Background (Mild NPDR)

Pre-proliferative

Proliferative

Diabetic maculopathy

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5
Q

What is diabetic retinopathy?

A

Vascular disease of retina
Asymptomatic initially, progresses to visual impairment + blindness

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6
Q

What are the classes of diabetic retinopathy?

A

Non-proliferative diabetic retinopathy (NPDR)
Proliferative diabetic retinopathy (PDR)

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7
Q

What constitutes mild NPDR? (background retinopathy)

A

> ,1 microaneurysm

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8
Q

What constitutes moderate NPDR? (pre-proliferative)

A

Microaneurysms
Blot haemorrhages
Hard exudates
Cotton wool spots
Venous beading/ looping
Intraretinal microvascular abnormalities (IRMA)

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9
Q

What are cotton wool spots?

A

‘Soft exudates’
Areas of retinal infarction

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10
Q

What constitutes severe NPDR? (pre-proliferative)

A

4:2:1 rule
>20 blot haemorrhages in 4 quadrants
Venous beading in >, 2 quadrants
IRMA in >,1 quadrant

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11
Q

What is the hallmark feature of PDR?

A

Neovascularisation due to widespread retinal ischaemia

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12
Q

What are complications of PDR and why do these arise?

A

New vessels are fragile + prone to leaking
Complications: vitreous haemorrhage + tractional retinal detachment

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13
Q

In which patients is PDR more common?

A

T1DM

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14
Q

What is the prognosis of PDR?

A

If untreated, 50% blind in 2y

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15
Q

Describe early PDR

A

New vessels less than 1/3 of the disc area, no vitreous haemorrhage, and no tractional retinal detachment.

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16
Q

What characterises high-risk PDR?

A

Any of:
Neovascularization of the disc (NVD) >,1/3 of the disc area

NVD a/w vitreous or preretinal haemorrhage,

Neovascularization elsewhere (NVE) >,1/2 disc area with vitreous or preretinal haemorrhage.

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17
Q

What is diabetic macular oedema (DME)?

A

Complication of diabetic retinopathy + can occur at any stage
Most common cause of vision loss in those with diabetic retinopathy

18
Q

How does DME arise?

A

Fluid + protein deposits collect on/ under the macula, causing it to thicken + swell (oedema)

19
Q

How is DME classified?

A

Focal DME: foci of vascular abnormalities, primarily microaneurysms.

Diffuse DME: dilated capillaries in the retina.

20
Q

When can diabetic macula oedema be detected? What is the GS Ix?

A

NOT on a 2D photo unless there are exudates in the macula
Exudates suggest there is/ has been fluid
GS: OCT

21
Q

In which patients is diabetic maculopathy more common?

A

T2DM

22
Q

What is optical coherence tomography?

A

OCT provides cross-sectional view of retina
Often used when examining DME

23
Q

What investigations should be performed in diabetic eye disease?

A

HbA1c
Comprehensive dilated eye exam
Fundus photography
OCT
Fluorescein angiography

24
Q

What is the gold-standard technique for visualising the vasculature of the retina?

A

Fluorescein angiography

25
Q

Describe medical management of diabetic retinopathy

A

Glycemic control
BP control
Diet, exercise + smoking cessation

26
Q

What is the primary intervention in management of PDR and severe NPDR?

A

Photocoagulation
Using laser to create numerous burns in the retina, destroying photoreceptors
Reduced O2 demand
Delays progression

27
Q

What are the 2 methods of photocoagulation?

A

Focal photocoagulation
Pan-retinal photocoagulation

28
Q

What occurs in focal photocoagulation?

A

Specific point of leakage identified + targeted with the laser.

29
Q

What occurs in pan-retinal photocoagulation?

A

Periphery of retina targeted with aim of achieving a global reduction in O2 demand

30
Q

Tx for proliferative diabetic retinopathy

A

Pan retinal laser photocoagulation (PRP)
Induces regression of new vessels before they bleed/ re-bleed causing vitreous haemorrhage

31
Q

Following pan retinal photocoagulation for PDR, what do ~50% of patients develop?

A

Reduction in their visual fields due to scarring of peripheral retinal tissue

32
Q

List 3 complications of panretinal photocoagulation other than reduction in visual fields

A

Decrease in night vision (majority of rods (responsible for low light conditions) are on periphery)
Decrease in visual acuity
Macular oedema

33
Q

What intravitreal injections can be used in management of PDR?

A

Anti-VEGF: minimises neovascularisation
Corticosteroids: improve visual acuity + reduce maculopathy

34
Q

Name 2 anti-VEGF injections used in PDR

A

Aflibercept (Eylea)
Ranibizumab (Lucentis)

35
Q

Tx for diabetic macular oedema

A

Anti-VEGF Intravitreal injections
Macular laser (rarely) if allergy to drugs

36
Q

When may a vitrectomy be performed in management of PDR?

A

Persistent haemorrhage
Central, sight-threatening tractional retinal detachment

37
Q

List 3 complications of diabetic retinopathy

A

Neovascular glaucoma
Retinal detachment
Vitreous haemorrhage

38
Q

What is diabetic maculopathy?

A

Any structural abnormality due to diabetes affecting macula
Often preceded by diabetic retinopathy

39
Q

Ix for diabetic macular ischaemia

A

No fundal signs
Suspected in diabetic with unexplained poor vision (in absence of diabetic macular oedema)

40
Q

How should diabetic maculopathy be managed?

A

If change in visual acuity: intravitreal VEGF inhibitors

41
Q

How should NPDR be managed?

A

Regular observation
If severe: consider pan retinal photocoagulation