Table 1.

Progressive stages of diabetic retinopathy and the clinical signs.

Stages of diabetic retinopathy	Clinical signs
Mild NPDR	Microaneurysms
Moderate NPDR	Intraretinal hemorrhages, hard exudates, cotton wool spots, and venous beading less than required for severe NPDR
Severe NPDR	Extensive intraretinal hemorrhages in each of 4 quadrants, venous beading in more than 2 quadrants, and one intraretinal microvascular abnormality
PDR	Neovascularization, vitreous/preretinal hemorrhage

NPDR: nonproliferative diabetic retinopathy. PDR: proliferative diabetic retinopathy.