Microaneurysms Hemorrhage Hard Exudate Cotton-wool Intraretinal Microvascular Abnormalities (IRMA) Venous Beading New Vessels:(NVD) < 1 disc diameter from the optic nerve, (NVE) new vessels elsewhere, Vitreous & Preretinal Hemorrhages (VH) Fibrous Proliferations
The retinal capillary rnicroaneurysmis usually is the first visible sign of diabetic retinopathy identined clinically by ophthalmoscopy as deep-red dots varying from 15 to 60 micrometers in diameter, are most common in the posterior pole.
Hemorrhage within the nerve fiber layer tends to be flame shaped, (1). In the inner layer, hemorrhage is aligned at right angles to the retinal surface and is viewed end-on when using an ophthalmoscope; these hemorrhages appear dot (2) or blot shaped (3).
The clinical differentiation between dot hemorrhages and microaneurysms is difficult. Fluorescein angiography will discriminate. Vision is unaffected by these appearances but multiple blot hemorrhages imply significant retinal ischemia,
Discrete white-yellow lipid deposits in the posterior pole Commonly seen in a circinate pattern peripheral to the areas of leakage May present as large, confluent exudation Hard exudates are found principally in the macular region and as the lipids coalesce and extend into the central macula (fovea), vision can be severely compromised
As the retina becomes more ischaemic new blood vessels may arise from the optic disc or in the periphery of the retina. The vessels usually originate from large veins and are initially seen as fine tufts on the surface of the disc...
Mild NPDRMicroaneurysms only Moderate NPDR More than just microaneurysms but less than severe NPDR Severe NPDR (4-2-1 rule) and no signs of PDR Severe intraretinal H or MA in each of four quadrants, venous beading in two or more quadrants Moderate IRMA in one or more quadrants Very severe NPDR two or more of the characteristics of severe NPDR
Breakdown of blood-retinal barrier lead to: ◦ Leakage of plasma from small blood vessels in the macula ◦ Swelling of central retina ◦ Hard exudate from resorption of fluid Klein et al. Ophthalmology 1995;102:7-16
The leading cause of visual loss amongst diabetics. Diagnosed by stereoscopic assessment of retinal thickening, Defined as the presence of one or more of the following, ( Modified Airlie -House Criteria ) Retinal edema within 500 microns of the centre fovea. Hard exudates within 500 microns of fovea if associated with adjacent retinal thickening Retinal edema that is one disc diameter or larger, any part of which is within one disc diameter of the centre of the fovea.
PDR One or more of the following: Neovascularization Vitreous hemorrhage Preretinal hemorrhage high-risk PDR New vessels within 1 disc diameter of the optic disc that are larger than disc area. Vitreous or preretinal hemorrhage associated with less extensive new vessels at the optic disc, or with new vessels elsewhere ½ disc area or more in size.