What R0, R1 and M1 mean on your eye screening letter
Your screening result comes back as a code for each eye. Here is what the R and M grades stand for, and which ones lead to another appointment.
Your screening letter grades each eye with a letter and a number. R is retinopathy, the blood vessels across the back of the eye. M is maculopathy, the small central patch you read and recognise faces with. One line is one eye, so R1M0 is a whole result, not half of one.
- R0 means no retinopathy was seen, and M0 means nothing near the centre needs passing on.
- R1 is background retinopathy: small changes show in the photographs, and your sight is not affected by them.
- R2 upwards, and M1, mean a closer look rather than anything decided by post.
- Your GP gets a copy, and the letter usually arrives within about three weeks of the appointment.
What each retinopathy grade stands for
R0 means no diabetic retinopathy was seen in that eye. R1 is background retinopathy, and what the graders can see is microaneurysms (tiny bulges in the smallest blood vessels), small haemorrhages, or exudate (fatty deposits that have leaked out of a damaged vessel). The damage is visible in the photograph. Your sight is not affected by it, and nothing is treated at this stage.
R2 is pre-proliferative, and it splits in two. R2L is the lower-risk version, watched with extra imaging. R2H is the higher-risk version and always goes to hospital eye services. R3 is proliferative, where new and fragile vessels have grown. R3A means that is active and needs an urgent hospital referral. R3S means it was treated with laser and has stayed stable since, which is why a letter can carry an R3 that nobody is hurrying about.
Maculopathy, and the letters after it
The macula is the small central part of the retina that does the detailed seeing. M0 means nothing there met the threshold for passing on. M1 means it did, and the threshold is specific: a group of exudates at least half the area of the optic disc (the round spot where the nerve leaves the eye), all of it inside the macular area. M1 takes you out of the routine lane for a closer look: checks more often than once a year, usually including an OCT scan (a cross-section photograph of the layers of the retina), and an ophthalmology appointment if treatment turns out to be needed.
Some letters also carry a P grade. P0 means no sign of previous laser treatment at the back of the eye, and P1 means there is some. What decides the next step is the combination, which is why R1M0 and R1M1 lead to two very different letters.
Where each result sends you
Three destinations, and your letter should name one. Routine screening means you stay in the ordinary invitation cycle. Digital surveillance means the screening service keeps watching you itself, with extra photographs and usually an OCT scan, on recall intervals counted in months (the guidance lists 1, 3, 6, 9 and 12) rather than years. Hospital eye services means an appointment with an eye specialist, which is where treatment decisions get made.
Referable is the programme’s word for a result that leaves routine screening. R0M0 and R1M0 are not referable. R1M1, R2M0 and R2M1 are, as is R3A with either M grade, and a treated R3S sitting alongside an M1. In practice R2L and a stable R3S on its own are managed in surveillance, R2H goes to hospital eye services, and R3A goes there urgently. If your letter does not make clear which of the three you are in, the service that sent it can tell you.
It arrives when nothing feels different
Diabetic retinopathy does not usually cause symptoms at first. Your sight is normal, and the only place the change exists is in a photograph. That is why the programme photographs everyone rather than waiting for people to notice something, and why the letter lands in a week when you felt completely fine. Finding small background changes and doing nothing about them is an ordinary outcome of screening, not an alarm.
When the next invitation comes depends on what was found. Since October 2023 in England, people whose last two routine screens found no signs of retinopathy are invited every two years, and everyone else more often, or referred on. Pregnant women with diabetes are offered screening more often again. Each UK nation runs its own programme (Wales, for one, has Diabetic Eye Screening Wales), so a letter from outside England can use different wording and intervals. The appointment itself, drops and all, is covered in our eye screening guide.
What changes what your letter says
Retinopathy risk builds with time and with the things that strain small blood vessels, which is why blood pressure, cholesterol and smoking get named alongside glucose. That is also why one person can get R0 for years and then an R1, while someone else carries an R1 that sits still for a long time. Your two eyes can differ on the same letter, and a grade moving up one year does not tell you where it goes the next.
Letters that land on the mat
Examples, not instructions or doses.
The letter says background retinopathy and no treatment needed. It means the graders can see small changes in this year’s photographs that were not there before, which is the change the programme exists to spot early. It is a reason to ask what happens next, not a statement about your sight.
The right eye reads R1M0 and the left reads R0M0. Each eye is graded on its own photographs, so different codes are normal, and one eye reaching a referable grade is enough to move you on.
Not the hospital, and not a treatment plan. It is the screening service keeping a closer eye on you than the routine cycle allows, with extra photographs and usually an OCT scan.
Sometimes the photographs do not give a clear enough view of the back of the eye. The follow-up is a look with a slit lamp instead, and drops again, and it is about the pictures rather than a result.
Worth paying attention to
Questions that make an appointment useful
When it's urgent
A screening letter is never the route for a sudden change in your sight. If you suddenly cannot see out of one or both eyes, or you suddenly have severe eye pain, that is A and E or 999 straight away. Do not drive yourself: ask someone to take you, or call an ambulance. For vision that has changed but not like that, blurring, double vision, flashing lights or shapes, a dark shadow moving across your sight, or an eye that is red and painful, ask for an urgent GP appointment or contact NHS 111 the same day. A recent normal screening result does not rule any of this out, and none of it should wait for your next invitation.