Table 1

ETDRS final retinopathy severity scale (for individual eyes)

LevelSeverityDefinition
10DR absentMicroaneurysms and other characteristics absent
20Microaneurysms onlyMicroaneurysms definite; other characteristics absent
35Mild NPDROne or more of the following:
• Venous loops ≥D/1
• SE, IRMA, or VB=Q
• Retinal haemorrhages present
• HE ≥D/1
• SE ≥D/1
43Moderate NPDRH/Ma=M/4–5 — S/1 or IRMA=D/1–3 (not both)
47Moderately severe NPDRBoth L43 characteristics and/or 1 (only) of the following:
• IRMA=D4–5
• H/Ma=S/2–3
• VB=D/1
53Severe NPDROne or more of the following:
• ≥2 of the 3 L47 characteristics
• H/Ma ≥S/4–5
• IRMA ≥M/1
• VB ≥D/2–3
61Mild PDRFPD or FPE present with NVD and NVE absent; or NVE=D
65Moderate PDREither of the following:
• NVE ≥M/1 or NVD=D and VH or PRH=A or Q
•VH or PRH=D and NVE <M/1 and NVD absent
71High-risk PDRAny of the following:
• VH or PRH ≥M/1
• NVE ≥M/1 and VH or PRH ≥D/1
• NVD=2 and VH or PRH ≥D/1
• NVD ≥M
75High-risk PDRNVD ≥M and VH or PRH ≥D/1
81Advanced PDR: fundus partially obscured, centre of macula attachedNVD=cannot grade, or NVD <D and NVE=cannot grade in ≥1 field and absent in all others; and retinal detachment at centre of macula <D
85Advanced PDR: posterior fundus obscured, or centre of macula detachedVH=VS in fields 1 and 2; or retinal detachment at centre of macula=D
90Cannot grade, even sufficiently for level 81 or 85
  • Severity categories for characteristics graded in multiple fields are of the form ‘maximum severity/extent’, where maximum severity can be absent (A), questionable (Q), definitely present (D), moderate (M), severe (S), or very severe (VS), and extent is the number of fields at that severity level. For example, M/2–3 means that there are two or three fields from fields 3 to 7 with moderate severity, and none with higher severity.

  • ETDRS, Early Treatment Diabetic Retinopathy Study; DR, diabetic retinopathy; FPD, fibrous proliferations disc; FPE, fibrous proliferations elsewhere; HE, hard exudates; H/Ma, haemorrhages/microaneurysms; IRMA, intraretinal microvascular abnormalities; NPDR, non-proliferative DR; NVD, new vessels disc (within one disc diameter of disc margin); NVE, new vessels elsewhere (>1 disc diameter from disc); PDR, proliferative DR; SE, soft exudates; VB, venous beading; VH, vitreous haemorrhage; PRH, preretinal haemorrhage.