Degree of diabetic retinopathy depends on -
Microaneurysms in the macular area (the earliest detectable lesion).  Retinal haemorrhages both deep (dot and blot haemorrhages) and superficial haemorrhages (flame-shaped).  Hard exudates-yellowish-white waxy-looking patches are arranged in clumps or in circinate pattern. These are commonly seen in the macular area.  Retinal oedema characterized by retinal thickening.  Cotton-wool spots (if > 8, there is high risk of developing PDR).  Venous abnormalities, beading, looping and dilatation.  Intraretinal microvascular abnormalities (IRMA).  Dark-blot haemorrhages representing haemorr- hagic retinal infarcts. On the basis of severity of the above findings the NPDR has been fuher classified as under: 1. Mild NPDR  At least one microaneurysm or intraretinal hemorrhage.  Hard/soft exudates may or may not be present. 2. Moderate NPDR  Moderate microaneurysms/intraretinal hemorr- hage.  Early mild IRMA.  Hard/soft exudates may or may not present. 3. Severe NPDR. Any one of the following  Four quadrants of severe microaneurysms/ intraretinal hemorrhages.  Two quadrants of venous beading.  One quadrant of IRMA changes. 4. Very severe NPDR. Any two of the following  Four quadrants of severe microaneurysms/ intraretinal hemorrhages.  Two quadrants of venous beading.  One quadrant of IRMA changes. Ref Comprehensive ophthalmology AK Khurana 4th edition page no 494
Type of disease
Duration of disease
Severity of disease
Retinal involvement
Vitreous and retina