diabetic grades

All images are initially reviewed and graded by a primary grader using the ‘features-based’ grading scheme mentioned above. The grader identifies specific retinal features and ticks the relevant boxes in the grading template which generates a nationally recognised diabetic retinopathy grade (R0, R1, R2, R3S, R3A) and maculopathy grade (M0, M1).

The grading pathway the patient will follow is determined by the initial primary grade.

In 90% of cases graded R0M0 (ie the primary grader detects no diabetic retinopathy), the results of grading are sent to the patient and their GP, with the patient being enrolled into an routine annual screening.

The remaining 10% of cases graded as R0M0, will go forward in the grading pathway to be second grade as part of the internal quality assurance. Primary graders outcomes against final grade are monitored regularly to highlight any areas where additional training is required to maintain excellence within the grading pathway.

New graders also initially have 100% of their primary grades reviewed at secondary until it can be shown that their grading quality is consistent and of a high standard.

o R1, R2, M1
All cases of diabetic eye disease (excluding proliferative eye disease) detected at the primary grade will go forward in the grading pathway to a secondary grade. The secondary grader is not able to see the primary grade.

o R1M0: If the primary and secondary graders agree on this final grade the results are sent to the patient and GP and the patient will be re-invited for routine annual screening.





o Referable retinopathy: R1M1, R2M0, R2M1: If the primary and secondary graders agree on this grade the patient goes forward in the grading queue to the Referral Outcome Grader for a final assessment.

o R3S, R3A: If proliferative eye disease is detected at primary grade or subsequently at secondary grade the patient is fast-tracked directly to the Referral Outcome Grader




o Unassessable: If the primary or secondary grader considers that the images are not of sufficient quality to be safely graded they go forward to the Referral Outcome Grader.

o Urgent non-DR lesion: If the primary or secondary grader considers that there is a potentially sight-threatening non-diabetes related lesion they go forward to the Referral Outcome Grader

Arbitration Grade: If the primary and secondary graders disagree on the grade it will go forward to the arbitration grader. The arbitration grader does have access to both the primary and secondary graders outcomes and is the final arbiter for the grade. The arbitration grader is in a good position to build an impression of individual graders performance.


Referral Outcome Grade: This is considered to be the final outcome grade and this is carried out by a senior level grader supervised by the clinical lead. This grader is able to choose the final action outcome which includes referring patients to the Hospital Eye Services (including urgently for proliferative diabetes eye disease), slit lamp biomicroscopy (for unassessable images), digital surveillance (for borderline routine referable grades) or routine annual screening (for non-referable grades).