Hi Conor, for retinopathy there is a scale of severity from NSC R0 meaning no retinopathy and a normal retina whilst NSC R3 is the most serious (I think in Scotland they have a slightly different grading system with NSC R4 as the worst).
I've been Type 1 for almost 40 years and for about half of that had NSC R1 so signs of non-proliferative diabetic retinopathy. This had no impact on my sight and was monitored.
In the last few years on a low-carb diet my retinopathy has reversed; at my last 2 eye screenings I have had NSC R0 - so there is no sign of it. It can be done!
It took me a long time to get rid of it but it is possible.
Best
Dillinger