Table 1

Welsh Community Diabetic Retinopathy Study. (Abbreviated clinical groupings)

Clinical grouping:
0 No diabetic retinopathy.
1 Non-proliferative retinopathy: non-PDR (mild). Occasional haemorrhages and/or microaneurysms and exudates not within one disc diameter of the macula centre. One cotton wool spot per eye not associated with preproliferative lesions.
2a Non-proliferative retinopathy: non-PDR (moderate) without macular involvement. Large circinate or plaque of exudates within the temporal vascular arcades, but not within one disc diameter of the macula centre (fovea).
2b Non-proliferative retinopathy: non-PDR (moderate) with macular involvement (maculopathy). Haemorrhages and/or exudates within one disc diameter of the macula centre not including microaneurysms.
3 Pre-proliferative retinopathy: (PPDR). Venous irregularities (beading, reduplication, loops) and/or multiple haemorrhages and/or multiple cotton wool spots and/or intraretinal microvascular abnormalities.
4 Proliferative retinopathy: (PDR). New vessels on the disc or elsewhere on the retina. Preretinal haemorrhage and/or fibrous tissue.
5 Advanced diabetic eye disease. Vitreous haemorrhage and/or fibrous tissue and/or recent retinal detachment and/or rubeosis iridis.