Systemic disease

Question 1

Blood pressure target

Answer 1

Keep below 150/85 mmHg

Question 2

Main ocular problems in diabetes

Answer 2

Retinopathy and cataracts

Question 3

Usual state of eyes at presentation of diabetes

Answer 3

Lens may have higher refractive index therefore relative myopia - this reduces with treatment therefore wait to correct refractive errors until diabetes is controlled

Question 4

What are the structural changes associated with diabetes

Answer 4

Accelerates productive and progress of age related cataracts - and in young (lens takes up glucose converted by aldolase reductase to sorbitol)
Also ischaemia can cause rubeosis, this can block drainage of aqueous leading to glaucoma

Question 5

Pathogenesis of retinopathy

Answer 5

Microangiopathy in small vessels of the eyes causes occlusion +/- leakage

Question 6

What does vascular occlusion in diabetic retinopathy lead to?

Answer 6

Ischaemia and new vessel formation - proliferative retinopathy
New vessels bleed = vitreous haemorrhage
Also retraction of retina fibres that run with new vessels risks retinal detachment
Also cotton wool spots (nerve ischaemia)

Question 7

What does vascular leakage in diabetic retinopathy lead to?

Answer 7

Pericytes lost
Vessels bulge - microaneurysms (dots)
There is oedema and hard exudates (yellow patches)
Rupture of these microaneurysms causes flame haemorrhages and when deep in the retina = blot haemorrhages

Question 8

Grading of diabetic retinopathy

Answer 8

Mild, moderate and severe non-proliferative (just signs of ischaemia)
Proliferative retinopathy
Maculopathy - leakage from vessels close to macula

Question 9

What can accelerate diabetic retinopathy

Answer 9

Pregnancy 
Dyslipidaemia
HTN
Renal disease
Smoking
Anaemia

Question 10

Interventional treatment of diabetic eye disease

Answer 10

Photocoagulation for maculopathy (focal or grid) and proliferative retinopathy (panretinal)

Question 11

Medication treatment of diabetic eye disease

Answer 11

Intravitreal triamcinolone

Anti-vegF for macular oedema

Question 12

CNS effects of diabetic eye disease

Answer 12

Ocular palsies may occur - typical CN III and VI

In CN III palsy pupil may be spared because nerve fibres run peripherally in nerve and receive alternate blood supply

Question 13

Side effects of panretinal photocoagulation

Answer 13

Does not improve vision only helps prevent blindness
May cause some loss of peripheral, colour and night vision
May get general blurring - usually transient but may persist