Table 1: Classification of diabetic retinopathy [12].

GradeDescriptionLesion

R0No retinopathyNo apparent retinopathy

R1Background retinopathyMicroaneurysm(s)
Retinal haemorrhage(s) ± any exudate

R2Preproliferative retinopathyVenous beading, venous loop, or reduplication
Intraretinal microvascular abnormality (IRMA)
Multiple deep, round, or blot haemorrhages

R3Proliferative retinopathyNew vessels on disc (NVD)
New vessels elsewhere (NVE)
Preretinal or vitreous haemorrhage
Preretinal fibrosis ± tractional retinal detachment

M0No maculopathyNo apparent maculopathy

M1Maculopathy presentExudate within 1 disc diameter (DD) of the centre of the fovea
Circinate or group of exudates within the macula
Retinal thickening within 1 DD of the centre of the fovea (if stereo available) 
Any microaneurysms or haemorrhage within 1 DD of the centre of the fovea only if associated with a best VA of ≤6/12 (if no stereo)