Image Galleries - R2 or Not?

R2 or Not?'R2 or Not?'

This section of the website has been set up in order to explore what R2 is – or is not – in terms of grading diabetic retinopathy images.*  Retinal graders are faced with the task of assessing images in accordance with national definitions and are also required to complete online quality assurance tests on a regular basis, in order to maintain grading competency.

There continues to be much debate, however, over the definition of R2 and the features of pre-proliferative retinopathy, with graders often disagreeing on whether an image should be classified as R2.  In England, the Diabetic Eye Screening Feature Based Grading Form classifies R2 as Pre-proliferative retinopathy with one or more of: venous beading, venous reduplication, multiple blot haemorrhages and intraretinal microvascular abnormalities (IRMA).  These must be present in addition to at least one microaneurysm or retinal haemorrhage.

In an effort to clarify what constitutes R2, BARS Council has decided to set up a monthly challenge.  We would like graders to assess three images each month, all of which have been previously classified as R2, and give an opinion on whether or not you agree with this grade. The aim is to gauge what level of consensus exists and where areas of disagreement may lie, as well as to assist trainees in recognising the features of pre-proliferative diabetic retinopathy.

How to Take Part

Below you will see a set of 3 retinal images.  Each is presented in the original colour version and a red-free version, and clicking on the thumbnail will open the full-size version in a new window or tab in your browser. Image manipulation tools are not included and it is not necessary to use them, but you may right-click the image and save to your computer if you wish to adjust it using your own software.

Your task is simply to decide if you agree that the image should be graded as R2, according to the current definition used by NDESP. The definition is available in full on the PHE website at this address:

When you click the Start button below, you will be asked to give a decision for each image in turn, and will be able to enter comments if you wish, explaining your decision further.

Your responses are anonymous, and you are not required to enter any personally identifiable information. At the end of each month, results will be collated and published on the BARS website, along with the comments received for each image. We intend to present a new set of three images each month, with all past results being accessible, forming a useful library of R2 images and information which we hope will assist trainees and experienced graders alike.

If you would like to submit any images for possible use in a future month's ‘R2 or Not?' challenge, please ask your programme manager to contact us at

Thanks for taking part! Review the images below, then click Start to begin.  For previous month's results please go to bottom of page and click on relevant section.

Images for June 2018

Image 1


Image 2


Image 3


Please click: if you cannot access the Start button.

*Please note that in Scotland, the grading scheme differs from elsewhere in the UK, and the Scottish grade of R3 (‘Referable Background') can broadly be considered as the equivalent of the English R2 grade.


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