Diabetic Retinopathy

Question 1

Risk factors and pathogenesis for DR

Answer 1

-Duration of diabetes
-Poor control of diabetes
-Pregnancy
-Hypertension
-Nephropathy
-Smoking
-Obesity

=Occlusion, ischaemia, VEGF, leakage, macular oedema, blood-retinal barrier breakdown
=Hyperglycaemia, increased retinal blood flow and abnormal metabolism in retinal vessel walls= damage endothelial cells

Question 2

Describe mild non-proliferative DR

Answer 2

-Micro aneurysms
-Haemorrhages
-Exudates
-Cotton wool spots
-Review in 6-12 months

Question 3

Describe moderate non-proliferative DR

Answer 3

-Severe haemorrhages in 1-3 quadrants
-Venous beading in 1 quadrant
-≥1 cotton wool spots
-Review in 6 months

Question 4

Describe severe non-proliferative DR

Answer 4

The 4-2-1 rule; ANY OF:
-Severe haemorrhages in all 4 quadrants
-Venous beading in ≥2 quadrants
-Moderate IRMA in ≥1 quadrants
-Review in 1-4 months

Question 5

Treatment of proliferative DR

Answer 5

-New vessels on the disc or elsewhere (neovascularisation)
-Treat with intravitreal anti-VEGF or laser coagulation (PRP= pan-retinal photocoagulation). Spares only the macula. Reduces oxygen demand but leaves tunnel vision, night blind (rids of rods), cannot drive.

Question 6

Describe advanced diabetic eye disease

Answer 6

-Vitreous haemorrhage
-Tractional retinal detachment
-Rubeosis iridis (glaucoma risk factor)

-Treated with pars plana vitrectomy

Question 7

Treatment and investigation of diabetic macular oedema

Answer 7

-Direct visualisation through fundus exam (grey dark macula, dot blot haemorrhages, exudates)
-Fundus Fluorescein Angiography (FFA): leakage, petaloid oedema, capillary non-perfusion (ischaemia)
-Optical Coherence Tomography (petaloid hyporeflection/ fluid)

-Intravitreal anti-VEGF (when centre vision involved, vision less than 6/9 otherwise observation) or laser coagulation (macular laser therapy when centre vision spared)

Question 8

What is diabetic maculopathy?

Answer 8

MOST LIKELY CAUSE OF DECREASED VISION IN T2DM

-Foveal oedema
-Hard exudates
-Ischaemia

-Diffuse= extensive capillary leakage
-Local= focal leakage from microaneurysms and dilated capillaries

Question 9

What is proliferative diabetic retinopathy?

Answer 9

-Neovascularisation on or within one disc diameter of the disc (NVD) and/or new vessels elsewhere in the fundus (NVE)

=leaky vessels, blood in vitreous, fibrous tissue formed and contracts, pulling on retina, retinal tears

Question 10

Describe hypertensive retinopathy

Answer 10

-Presentation: arteriolar narrowing and tortuosity, arteriovenous nipping, cotton wool spots, vascular leakage leading to flame shaped haemorrhage and retinal oedema. Chronic oedema= hard exudates in fovea= macular star configuration. Swollen optic head/ papilledema (malignant hypertension), copper/ sliver wiring (thickening of vessel walls
-Investigation: BP
-Management: blood pressure management