Diabetic Retinopathy

In station 5 you may be asked to assess a diabetic patient who has concerns about their vision


History (3 minutes) – patient tells you that his vision is blurred and he is worried that he is going blind


  • Blurred at all distances- near and far?
  • Blurred even with glasses/contact lenses? Change in prescription?
  • Timing- since when, sudden/gradual?, all the time/come and go, getting worse, previous episodes
  • 1 or both eyes
  • Painful/painless
  • Any loss of vision? Bits missing? Bumping into things?
  • Any double vision?
  • Any floaters? Dark spots? Flashers?
  • Any halos? Glare?
  • Impact on life
  • Do you drive? (group 1 or group 2)
  • PMH, Fx, Dx including treatments so far, Sx


  • Take diabetic history:
    • When diagnosed? Type 1 or type 2?
    • Treatment and compliance
    • How well controlled is it? What are sugar levels? Target? Recent Hba1c?
    • Any hospital admissions because of diabetes?
    • Eye problems in past? Attend screening? Treatment? Laser? Ever seen eye doctor?
    • Kidney problems? BP? Hypos? (how often, awareness of hypos)
    • Nerve problems? Pins and needles/numbness? Bladder? Erectile dysfunction? Walking, falls?
    • Feet problems? Ulcers? Pulses? Claudication?
    • CVS Risk factors and PMH- MI, stroke etc.


Examine (3 minutes)


  • Visual Acuity
  • Fundoscopy: dots, blots, exudates, cotton wool spots, venous beading and looping , intraretinal microvascular abnormalities, new vessel formation at the disc or elsewhere, maculopathy
  • If time allows- Visual fields, eye movements, pupils
  • Offer to check BP and CBG
  • If time allows, look for diabetic fingerprick marks, examine the feet for ulcers and peripheral neuropathy, do a quick CVS assessment


ICE and Explanation (2 minutes)


Reassure the patient that there is no evidence of anything immediately sight threatening (if this is the case) but given his symptoms explain that you’d like to refer him to an eye doctor because they have better equipment and can get a 3D view.

Explain that you’d like to check his blood sugar today and Hba1c to see if his diabetes is well controlled

Explain that you’d also like to check BP, cholesterol, ECG, urine dipstick, renal function and advise him to stop smoking, lose weight etc.

Tell him not to drive until seen by the eye doctor


You could explain diabetic retinopathy as follows:

“There is damage to tiny blood vessels which supply the retina at the back of your eye where light is focussed on. High blood sugar weakens and damages these blood vessels which then bleed, leak fluid, swell and block. This damages the retina, new vessels grow, which are delicate and bleed. It’s possible to laser these new vessels”


Explain that without treatment his vision can get worse

High BP can make the situation worse

Need to get diabetes under better control and BP and cholesterol to prevent further deterioration and other problems.

Offer to arrange an appointment with a diabetic specialist nurse





Make sure you know the stages of diabetic retinopathy and what you see on fundoscopy at each stage


Standards of vision for driving:

  • Wear glasses/ contacts if needed
  • Tell DVLA if problem with vision (not necessary for short/long sightedness)
  • Must be able to read number plate from 20 metres
  • Must have visual acuity 6/12 when both eyes are tested together
  • Must have field of vision of at least 120 degrees horizontal
  • For lorry/bus driver: must be 6/7.5 in the best eye and 6/60 in the other eye, horizontal field 160 degrees


Tell DVLA if:

  • >1 episode of severe hypoglycaemia within last 12 months (NB: single episode of severe hypoglycaemia for group 2 drivers)
  • Impaired awareness of hypoglycaemia
  • Treatment with insulin
  • Need for laser treatment
  • Problems with vision in both eyes
  • Problems with the circulation or sensation in legs or feet necessitating driving automatic vehicles only
  • Treatment with tablets (for group 2)


Refer to ophthalmology if:

  1. Maculopathy
  2. Severe Non-proliferative diabetic retinopathy
  3. Proliferative diabetic retinopathy (urgent 2 week referral)


Differential diagnoses:

  1. Diabetic retinopathy/retinal detachment/macular degeneration
  2. Migraine
  3. Transient Ischaemic Attacks
  4. Postural hypotension
  5. Hypoglycaemia


Other visual problems in diabetic patients:

  1. Maculopathy
  2. Vitreous haemorrhage
  3. Retinal detachment
  4. Central retinal artery occlusion/branch retinal artery occlusion
  5. Central retinal vein occlusion/branch retinal vein occlusion
  6. Stroke/TIA
  7. Ischaemic optic neuropathy
  8. Glaucoma
  9. Cataract
  10. Ocular muscle palsies


Written by Dr Sarah Kennedy


Resources used to write this document include those listed in the references section of this webpage as well as: