DR: ETDRS grading protocol. International clinical diabetic retinopathy disease severity scale

Proposed disease severity level	Findings observable with dilated ophthalmoscopy
No apparent DR	No abnormalities
Mild nonproliferative DR	Micro aneurysms only
Moderate nonproliferative DR	More than “mild” but less than “severe”
Severe nonproliferative DR	Any of the following 20 or more intraretinal hemorrhages in 4 quadrants Definite venous beading in 2 or more quadrants Prominent IRMA in 1 or more quadrants and no neovascularization
Proliferative DR	1 or more of the following Definite neovascularization Preretinal or vitreous hemorrhage

IRMA: Intraretinal microvascular abnormalities, ETDRS: Early treatment diabetic retinopathy study