Diabetic Retinopathy

Question 1

Pathophysiology

Answer 1

Hyperglycaemia
- increases retinal blood flow and abnormal metabolism in the retinal vessel walls
=> damage to endothelial cells and pericytes

Endothelial dysfunction leads to increased vascular permeability => exudates

Pericyte dysfunction predisposes to the formation of microaneurysms

Neovasculisation
- caused by production of growth factors in response to retinal ischaemia

Question 2

3 classifications of diabetic retinopathy

Answer 2

non-proliferative diabetic retinopathy (NPDR)

proliferative retinopathy (PDR)

maculopathy

Question 3

Describe the difference between Mild->Mod->Severe NPDR

Answer 3

Mild NPDR
- 1 microaneurysm

Moderate NPDR
- microaneurysms
- blot haemorrhages
- hard exudates
- cotton wool spots
- venous beading/looping

Severe NPDR
- blot haemorrhages and microaneurysms IN ALL QUADRANTS
- venous beading in at least 2 quadrants
- intraretinal microvascular abnormalities in at least 1 quadrant

Question 4

Common features of proliferative diabetic retinopathy

Answer 4

retinal neovascularisation - may lead to vitrous haemorrhage

fibrous tissue forming anterior to retinal disc

Question 5

Is proliferative diabetic retinopathy more common in T1DM or T2DM?

Answer 5

T1Dm

Question 6

Describe the features of maculopathy in diabetic retinopathy

Answer 6

hard exudates and other changes on macula

Question 7

Is maculopathy more common in T1 or T2DM?

Answer 7

T2DM

Question 8

Common management of all patients with diabetic retinopathy

Answer 8

• better BM and BP control
• lipid control
• regular review by ophthalmology

Question 9

Tx of NPDR

Answer 9

• regular observation
• if severe consider panretinal laser photocoagulation

Question 10

Tx of maculopathy

Answer 10

if change in visual acuity then
intravitreal VEGF INHIBITORS

Question 11

Tx of proliferative DR

Answer 11

• panretinal laser photocoagulation
• intravitreal VEGF inhibitors

if severe or vitreous haemorrhage
=> vitreoretinal surgery

Question 12

Complications of panretinal laser photocoagulation

Answer 12

• reduction in visual fields due to the scarring of peripheral retinal tissue
• decrease in night vision (rods = responsible for night vision and majority are located in the peripheral retina)
• generalised decrease in visual acuity and macular oedema