Diabetic Eye Screening

Depending on which part of the UK you are testing there are different quality assured testing schemes.  According to the College Of Optometrists, if you are not officially certified with your local Diabetic Eye Screening scheme,  you can not use the term ‘Diabetic Screening’ when assessing your patients.  If a patient is not part of their local NHS Diabetic Eye Screening Programme, you should offer them a dilated fundus exam along with retinal photography.


A detailed Diabetic Eye Screening should include:

Detailed History and Symptoms

  1. Date of diabetes diagnosis and whether they have type 1 or 2
  2. Is the diabetes well controlled or not
  3. Is it diet controlled or are they taking medications, insulin or both
  4. What other medications are they taking and for what
  5. Do they have high blood pressure, high cholesterol or any other health concerns
  6. Do they have any other complications related to diabetes for example any problems with their kidneys or feet
  7. Do they smoke
  8. Are they overweight


Vision check (Aided or pinhole VA)

  1. Check their aided visual acuity (VA) if possible
  2. If their VA is below 6/9 check it with a pinhole to see if it improves

Intraocular Pressure Check

  1. Preferably check with contact tonometry
  2. If IOP over 21, check pachymetry and adjust IOP accordingly
  3. If IOP over 28, do not dilate and discuss with an Ophthalmologist if working in a hospital setting


  1. Check anterior chamber angle prior to instilling the drops (using van hericks or gonioscopy)
  2. Instruct patient to wait for 20-30 minutes prior to examination
  3. Once dilated, you can choose to screen by taking a photo or by using a slit lamp
  4. Normal procedure is to take a photograph if the media is clear enough and the pupil is dilated efficiently
  5. If the patient is a poor dilator or has significant cataracts, a slit lamp examination is required

What you are looking for and how to grade

Grading system:

R0M0 – no diabetic retinopathy

R1MO -background peripheral retinopathy but no maculopathy

R1M1 – background retinopathy with macular retinopathy                                                                                                                                                                 (note – even if the macular is only involved and there is no peripheral retinopathy, it is still R1M1, R0M1 DOES NOT EXIST)

R2M0 – pre – proliferative peripheral retinopathy but no maculopathy

R2M1 – pre-proliferative peripheral retinopathy and maculopathy

R3MO – proliferative peripheral retinopathy and no maculopathy

R3M1 – proliferative peripheral retinopathy and maculopathy



Grade Other Terms SymptomsFundus exam Action
 RO No DR/grade ONo Normal retina review 12/12 or 18/12
 R1 Mild non or pre -proliferative/background DR/grade 1 No/VA loss if M1 Microaneurysms (MAs) and haemorrhages, few Cotton Wool Spots (CWS) review 12/12 if in hosp setting, otherwise refer
 R2non/pre- proliferative DR (can be moderate or severe) Grade 2/3 No/VA loss if M1Extensive MAs, haemorrhages, CWS, pre-retinal haemorrhage, mild IRMA refer to Ophthalmologist at HES
 R3 Proliferative DR/grade 4 VA loss, flashes and floaters All of above plus new vessels at the disc or else where (NVD/NVE).  Vitreous heamorrhage and retinal detachment possible here Urgent referral to Ophthalmologist at HES
 R3s (s=stable) Treated proliferative retinopathy No new leakage or new vessels Review 12/12
 M0 No maculopathy Review 12/12
 M1 Diabetic MaculopathyMaculopathy varies:

Mild maculopathy:

  • exudate < or = 1DD from centre of fovea
  • circinate or group of exudates within macula
  • any microaneurysm or haemorrhage < or = 1DD from centre of fovea only if associated with a best VA of < or = 6/12

Clinically Significant Macular Oedema (CSMO)

CSMO is when there is leakage within the foveal area and VA is below 6/12.

Exudative maculopathy:

Leakage, retinal thickening, MAs, hard exudates at the macula. Ischaemic form can have a featureless macular with NVE and poor vision.

   Refer to HES
P Photocoagulation/Grade 4b Glare, reduced night vision Small peripheral retinal scars where laser has been done
 UG/OL Un-gradable/Other lesion Possible reasons for Ungradable include cataracts/corneal haze/poor dilator.  If other lesion is seen, refer for assessment