Classification

Non Proliferative Diabetic Retinopathy (NPDR)

NPDR is further subdivided based on retinal findings:

Early/Mild NPDR – At least one microaneurysm present on retinal examination.

Moderate NPDR – Characterized by multiple microaneurysms, dot-and-blot hemorrhages, venous beading, and/or cotton wool spots.

Severe NPDR – In the most severe stage of NPDR, you will find cotton wool spots, venous beading, and severe intraretinal microvascular abnormalities (IRMA). It is diagnosed using the “4-2-1 rule.” A diagnosis is made if the patient has any of the following: diffuse intraretinal hemorrhages and microaneurysms in 4 quadrants, venous beading in ≥2 quadrants, or IRMA in ≥1 quadrant. Within one year, 52-75% of patients falling into this category will.

Proliferative Diabetic Retinopathy (PDR)

This stage is marked by formation of new blood vessels (Neovascularization). These new blood vessels are leaky, fragile, and often misdirected. They may even grow off the retina and into the vitreous. As the vitreous shrinks with age, it pulls on these fragile vessels and can cause them to tear, resulting in a vitreous hemorrhage and sudden vision loss.