Table 1. Classification used by the Scottish Diabetic Retinopathy Grading System*.

*[14]

NPDR: nonproliferative diabetic retinopathy; ETDRS: Early Treatment for Diabetic Retinopathy Study

Grades	Clinical features
R0	No retinopathy
R1	Background: microaneurysms, retinal hemorrhages, with/without any exudate. This is broadly equivalent to the ETDRS mild NPDR stage
R2	Pre-proliferative: multiple blot hemorrhages, intraretinal microvascular abnormalities (IRMAs). Moderate NPDR, referable to ophthalmology
R3	Proliferative diabetic retinopathy