Diabetes and diabetic retinopathy Flashcards
What is the normal range for the fasting blood glucose test?
3.9-5.5mmol/l
What is considered possibly diabetic for the fasting blood glucose test?
> 7mmol/l
What does the HbAc1 test look for and how long does it show results for?
Glycated haemoglobin
Previous 6-8 weeks
What is the normal range for the HbAc1 test?
20-41mmol/mol
What is considered possibly diabetic for the HbAc1 test?
> 48mmol/mol
What is needed to diagnose diabetes?
Symptoms +
fasting blood glucose >7mmol/l
OR blood glucose >11.1mmol/l
OR oral glucose tolerance >11.1mmol/l 2 hours after eating
OR HbAc1 >48mmol/mol
Repeat tests if no sxs to confirm diagnosis
What are the risk factors for diabetes?
Smoking
Poor diet
Lack of exercise
Obesity
FH
HBP
Gestational diabetes
Impaired glucose tolerance
South Asian/African/Afro Caribbean ethnicities
What is diabulimia?
Intentional reduction in insulin use to reduce weight (causes severe hyperglycaemia)
What is ketoacidosis?
Increase in blood glucose when there is reduced insulin. Fat is used for energy and ketones are released - risk to life.
What is the treatment for ketoacidosis?
Fluids and insulin
What is the treatment for T1 diabetes?
Regular examination
Control weight
Monitor HbAc1
Keep BP at 130/180 or below
Self monitor blood glucose before meals
Self administer insulin
What is the treatment for T2 diabetes?
Regular examination
Increase exercise
Improve diet
Pharmacological (e.g. metformin)
Monitor HbAc1
Keep BP at 130/180 or below
Insulin (last resort)
What are some common ocular complications of diabetes?
Diabetic retinopathy
Diabetic maculopathy
Refractive error changes
Iridopathy
What are some uncommon ocular complications of diabetes?
Early onset cataract
Styes
Blepharitis
Xanthelasma
Recurrent subconjunctival haemorrhage
Ocular motor palsies
Reduced corneal sensitivity
Corneal ulcers
Rubeosis iridis
What are the risk factors for diabetic retinopathy?
Longer duration
Pregnancy
Poor control
Kidney disease
Obesity
HBP
How does DR occur? i.e. what is the mechanism?
Increased blood glucose thickens blood viscosity, causing a thickened basement membrane.
This causes pericyte degeneration and endothelial degeneration/proliferation which damages microvasculature, causing leakage.
Leakage from vessels results in oedema/exudates and growth factors are stimulated, causing neovascularisation, leading to haemorrhage and oedema.
What are the signs of background DR?
Microaneursyms
Hard exudates
Dot/blot/flame haemorrhage
Retinal oedema
What are the signs of pre-proliferative DR?
background DR +
CWS
IRMA
venous beading and looping
ischaemic signs
What are the signs of proliferative DR?
Pre-proliferative +
Neovasc (NVD, NVE)
Pre-retinal haemorrhage
Vitreous haemorrhage
Tractional retinal detachment
What are the signs of maculopathy?
Loss of foveal pit
Retinal thickening
Ischaemia
Cystoid oedema
Haemorrhage
How should background DR be managed?
Sugar control
Annual DR screening
Annual ST
Inform GP of findings
How should pre-proliferative DR be managed?
Sugar control
Annual DR screening
Annual ST
Inform GP of findings
Routine/urgent referral dependent on findings for PRP
How should proliferative DR be managed?
Urgent HES referral for PRP/Anti-VEGF/Pars plana vitrectomy
How should diabetic maculopathy be managed?
Routine referral (within 13 weeks) for Anti-VEGF, steroid implant, macular PRP, statins.
