Table 3.

ETDRS Diabetic Retinopathy Classification of Progression to Proliferative DR

ETDRS final retinopathy severity scale [26]	ETDRS (final) grade	Lesions	Risk of progression to PDR in 1 year (ETDRS interim)
No apparent retinopathy	10 14, 15	DR absent DR questionable
Mild non-proliferative diabetic retinopathy (NPDR)	20	Micro aneurysms only
	35 a b c d e	One or more of the following: Venous loops > definite in 1 field SE, IRMA, or VB questionable Retinal haemorrhages present HE > definite in 1 field SE > definite in 1 field	Level 30 = 6.2%
Moderate NPDR	43a b	H/Ma moderate in 4–5 fields or severe in 1 field or IRMA definite in 1–3 fields	Level 41 = 11.3%
Moderately severe NPDR	47 a b c d	Both level 43 characteristics – H/Ma moderate in 4–5 fields or severe in 1 field and IRMA definite in 1–3 fields or any one of the following: IRMA in 4–5 fields HMA severe in 2–3 fields VB definite in 1 field	Level 45 = 20.7%
Severe NPDR	53 a b c d	One or more of the following: > 2 of the 3 levels, 47 characteristics H/Ma severe in 4–5 fields IRMA > moderate in 1 field VB > definite in 2–3 fields	Level 51 = 44.2% Level 55 = 54.8%
Mild PDR	61a b	FPD or FPE present with NVD absent or NVE = definite
Moderate PDR	65a b	(1) NVE > moderate in 1 field or definite NVD with VH and PRH absent or questionable or (2) VH or PRH definite and NVE < moderate in 1 field and NVD absent
High-risk PDR	71 a b c d	Any of the following: (1) VH or PRH > moderate in 1 field (2) NVE > moderate in 1 field and VH or PRH definite in 1 field (3) NVD = 2 and VH or PRH definite in 1 field (4) NVD > moderate
High-risk PDR	75	NVD > moderate and definite VH or PRH
Advanced PDR	81	Retina obscured due to VH or PRH