How does nonproliferative diabetic retinopathy differ from proliferative diabetic retinopathy?

Diabetic retinopathy is categorized into two primary stages based on the progression of vascular damage within the retina:

• Nonproliferative Diabetic Retinopathy: This is the early stage of the disease, characterized by damage to existing blood vessels. These weakened vessels may leak fluid into the retina, causing swelling, or form tiny aneurysms and small hemorrhages. Areas of the retina may also experience ischemia, or reduced blood flow.12
• Proliferative Diabetic Retinopathy: This is the advanced stage of the disease. It is defined by the growth of new, structurally unstable blood vessels on the retina, optic disk, or iris. Because these vessels are fragile, they are prone to bleeding into the vitreous cavity. This stage can lead to the formation of scar tissue, which may result in retinal detachment and other severe complications like glaucoma.12

While nonproliferative retinopathy lacks this abnormal vessel growth, it can progress to the proliferative stage if the underlying vascular damage remains unchecked.1