Guidance

Features-based grading outcomes guidance

Updated 12 May 2025

Applies to England

The following features-based grading provides details on the specific features which need to present in either eye to provide a grade for the screening encounter. Graders identify individual features of diabetic retinopathy (DR) by selecting a given feature from the feature-based grading (FBG) form within the software. This produces a grade which is determined by rules applied in the grading matrix software.

This guidance should be used in conjunction with the Diabetic Eye Screening pathway overviews guidance and should be used in routine digital screening, digital surveillance and slit-lamp biomicroscopy clinics.

Retinopathy grades (Rx)

R0: no retinopathy

• no features of diabetic retinopathy are present
• isolated cotton wool spots (one or more) in the absence of any microaneurysm or haemorrhage should be counted as no R0

R1: background retinopathy (stage 1)

• any microaneurysm
• any haemorrhage
• venous loops
• any exudate in the presence of other features of DR
• any number of cotton wool spots (CWS) in the presence of other features of diabetic retinopathy

R2L: pre-proliferative retinopathy - lower risk (stage 2)

R2L is defined as the presence of ANY of the described features and should be referred to digital surveillance for further imaging:

• venous beading in 1 quadrant
• 8 or more blot haemorrhages
• any quantity of IRMA less than ETDRS standard photograph 8a
• more than 20 intraretinal haemorrhages or microaneurysms located in 1,2 or 3 of the 4 quadrants of the retina where the quadrants are centred on the centre of the optic disc with a vertical line bisecting the disc vertically and horizontally

R2H: pre-proliferative retinopathy - higher risk (stage 2)

Higher risk (R2 H) is defined the presence of ANY of the described features and should be referred to Hospital Eye Services as routine:

• venous beading in two or more quadrants
• more than 20 intraretinal haemorrhages or microaneurysms in EACH of the four quadrants of the retina, where the quadrants are centred on the centre of the optic disc with a line bisecting the disc vertically and horizontally
• moderate IRMA equal to or worse than the Airlie House ETDRS standard photograph 8a in one or more quadrants

R3S: post-treatment stable proliferative retinopathy (stage 3 stable)

If discharged from the Hospital Eye Service (HES), a photography should be taken at or shortly after discharge from the HES that records these features:

• stable pre-retinal fibrosis plus peripheral retinal scatter laser
• stable fibrous proliferation (disc or elsewhere) plus peripheral retinal scatter laser
• stable R2 features (from feature-based grading) plus peripheral retinal scatter laser
• R1 features (from feature-based grading) plus peripheral retinal scatter laser

R3A: active proliferative retinopathy (stage 3)

R3A is defined the presence of ANY of the described features and should be referred to Hospital Eye Services as urgent:

• new vessels on disc (NVD)
• new vessels elsewhere (NVE)
• new pre-retinal or vitreous haemorrhage
• new pre-retinal fibrosis
• new tractional retinal detachment
• reactivation in a previous stable R3s eye

Maculopathy grades (Mx)

M0: no maculopathy

• absence of any M1 features
• any microaneurysm or haemorrhage within 1DD of the centre of the fovea if associated with a best visual acuity of ≤ 6/12 where the cause of the reduced vision is known and is not diabetic macular oedema

M1 referable diabetic maculopathy

• exudate within 1 disc diameter (DD) of the centre of the fovea
• group of exudates within the macula (A group of exudates is an area of exudates that is greater than or equal to half the disc area and this area (of greater than or equal half the disc area) is all within the macular area
• retinal thickening within 1DD of the centre of the fovea (if stereo available)
• any microaneurysm or haemorrhage within 1DD of the centre of the fovea only if associated with a best VA of ≤ 6/12 (if no stereo)

Optical coherence tomography (OCT) grades

Where OCT is available in digital surveillance, the following features should be identified to determine outcome. Find out more about optical coherence tomography (OCT) in diabetic eye screening (DES) surveillance clinics.

OCT negative

• OCT negative is defined as the absence of features required to meet the OCT positive or borderline criteria

OCT borderline

• intraretinal cysts within the DES defined macular area with no change in the foveal contour within the macular region

and/or

• an area of retinal thickening less than 1-disc area within the DES Programme definition of the macula but more than 1DD from the centre of the fovea providing there are no features which meet the OCT positive criteria

OCT positive

Intraretinal cysts together with one or more of:

• a change in the foveal contour
• an area of retinal thickening greater than 1/2-disc area, the edge of which is within 1 DD of the central fovea
• an area of retinal thickening greater than 1-disc area within the DES Programme definition of the macular

Photocoagulation grades

P0

• no evidence of previous photocoagulation

P1

• focal/grid to macula or peripheral scatter

Ungradable grades

U grade

• an image set that cannot be graded

Find further guidance on ungradable images is available.

Non-diabetic retinopathy features

The management and diagnosis of incidental findings (non-diabetic retinopathy) is not within the scope of the screening programme. Find more information on how to manage non DR.