What are the stages of diabetic retinopathy and how does it cause visual loss?
NPDR NPDR with multiple retinal hemorrhages Nonproliferative diabetic retinopathy (NPDR) is the earliest stage and the most common type of diabetic retinopathy. During this stage, the blood vessels become weak and balloon (microaneurysms). As the disease progresses, some of the blood vessels become leaky or get blocked depriving the retina of important nourishment. Flourescein Angiography showing fluid collection in macula Damaged blood vessels can leak fluid into the most essential central part of the retina (macula) causing it to swell, blurring vision. This condition called macular edema can occur at any stage of diabetic retinopathy, although it is more likely to occur as the disease progresses. PDR Proliferative Retinopathy (PDR) is the advanced stage when abnormal fragile blood vessels start forming on the retina. These fragile vessels can bleed inside the eye (vitreous hemorrhage) and even pull the retina out of its normal position (Tractional retinal detachment) causing severe
