Examining and grading retinopathy, for professionals

David Kinshuck


Diabetic Eye Screening Program

The Diabetic Eye Screening Program propose the following classification. Some centres use a more detailed classification, based on the NSC system proposal. The condition is graded by examination of digital retinal photographs, red free.




International Term


Features (see)


R0 No DR None Normal retina.   Grade 0 (US) annual rescreen
RI Mild none-proliferative (mild pre-proliferative) None Haemorrhages & microaneurysms, only      Grade 1 (US). Very minor IRMAs

Inform diabetes team

see M1

R2 Moderate none-proliferative, moderate  pre-proliferative None Previously termed mild pre-proliferative. Extensive Microaneurysm, intraretinal haemorrhage, and hard exudates.    Grade 2 (US)

refer HES


R2 Severe none-proliferative severe pre-proliferative None Previously termed severe pre-proliferative. Venous abnormalities, large blot haemorrhages, cotton wool spots (small infarcts), venous beading, venous loop, venous reduplication,
Grade 3 (US)

urgent refer HES


R3 Proliferative retinopathy Floaters, sudden visual loss New vessel formation either at the disc (NVD) or elsewhere (NVE).
Photos: flat new vessels,    raised,   florid       Grade 4a (US)

urgent refer HES


R3 Pre-retinal fibrosis+/- tractional retinal detachment Floaters, central loss of vision Extensive fibrovascular proliferation, retinal detachment, pre-retinal or vitreous haemorrhage, glaucoma.   Grade 4b (US). Traction o

urgent refer HES


R3s treated proliferative retinopathy (s = stable)   no haemorrhages or exudates or new vessels, laser ('P' added) annual rescreen
M 0     no maculopathy annual rescreen
M 1 Diabetic maculopathy Blurred central vision

The macula is defined as a circle centred on the fovea, with a radius of the distance to the disc margin. 
If the leakage involves or is near the fovea the condition is termed clinically significant macular oedema (CSME).

Exudative maculopathy presents with leakage , retinal thickening, microaneurysms, hard exudates at the macula. Ischaemic form can have a featureless macular with NVE and poor vision.
  Milder forms:

  • exudate < or = 1DD of centre of fovea
  • circinate or group of exudates within macula
  • any microaneurysm or haemorrhage < or = 1DD of centre of fovea only is associated with a best VA of < or = 6/12
    retinal thickening < or = 1DD of centre of fovea (if stereos available)

refer HES


P Photocoagulation Reduced night vision, glare Small retinal scars through out the peripheral retina. Grade 4b (US)  
Other lesion / Un-gradable   Un-gradable is usually due to cataract, other lesions usually referred for assessment  


Clinical Examination

Examination can also be carried out using an ophthalmoscope. This should include use of the green filter (red free) as It shows haemorrhages and new vessels much more easily, see . The slit lamp is very useful clinically.


Links..other grading systems in use

There are many studies in the academic literature, but few are available in full online. See and here.

Issues for Screening



Medical Control

If mild retinopathy is found, that is retinopathy without needing referral, there is an opportunity to inform the primary care team and get the diabetes under good control. However, this does not seem to be happening efficiently. We can calulate the risk of retinopathy progression www.risk.is.


10% of patients being screened are new patients...new patients are increasing at 5% a year.