Retinopathy

Question 1

What is the commonest cause of blindness in working age in people in the UK?

Answer 1

Diabetic retinopathy

Question 2

What are the risk factors for diabetic retinopathy?

Answer 2

• poor diabetic control
• age
• blood pressure

Question 3

Diabetic retinopathy has two main effects on retinal capillaries: leakage and occlusion.

What does capillary leakage result in?

Answer 3

• retinal haemorrhages (dot + blot)
• exudates
• macular oedema
  
  • commonest cause of blindness in DR
  • similar to wet AMD, treat w/ intravitreal anti VEGF injections

Question 4

What does occlusion of capillaries often cause?

Answer 4

• Locally → cotton wool spots
• Widespread occlusion of capillaries → global retinal ischaemia

Question 5

Neovascularisation (new blood vessels) is an unhelpful response to retinal ischaemia. This is also known as proliferative diabetic retinopathy (PDR).

What happens to the new blood vessels that are formed in PDR?

Answer 5

• bleed from retina into vitreous → vitreous haemorrhage
• fibrose + pull off retina → tractional retinal detachment
• grow on the iris + block trabecular meshwork → glaucoma

Question 6

What is the treatment of proliferative diabetic retinopathy?

Answer 6

• lasering whole retina except macula
• (anti-VEGFs trialed for PDR + promising)
• this removes ischaemic tissue + therefore the drive to produce new vessels

Question 7

All diabetics are screened for retinopathy with annual dilated retinal exams/photos. Photos are graded by trained screeners and patients referred if problems found. DR screening is an example of very successful screening.

What is the current grading system used?

Answer 7

• R0 → no retinopathy
• R1 → mild non proliferative (haemorrhages + microaneurysms)
• R2 → severe non proliferative (venous abnormalities, lage h’ges, cotton wool spots)
• R3 → proliferative retinopathy (new vessels at disc or elsewhere on retina)
• M0 → no maculopathy
• M1 → maculopathy (significant macular oedema or ischaemic macula)

Question 8

Hypertensive retinopathy is retinal vascular damage caused by hypertension. Signs usually develop late in the disease.

What does fundoscopic examination show?

Answer 8

• arteriolar constriction
• arteriovenous nicking
• vascular wall changes
• flame-shaped haemorrhages
• cotton wool spots
• yellow hard exudates
• optic disc oedema