Diabetic retinopathy is an eye condition that can cause vision loss and blindness in people with diabetes. It affects the retina’s blood vessels, the light-sensitive tissue at the back of the eye. High blood sugar levels over time can damage these tiny blood vessels, causing them to leak fluid or bleed. If left unmanaged, this damage can lead to severe vision loss.
Mild Non-Proliferative Diabetic Retinopathy
The earliest stage is mild non-proliferative diabetic retinopathy (NPDR). During this stage, small, balloon-like bulges called microaneurysms form in the retina’s tiny blood vessels. These microaneurysms may leak small amounts of fluid or blood into the retina. Individuals often do not experience noticeable symptoms or vision changes. The presence of microaneurysms indicates early vessel damage, making monitoring important.
Moderate Non-Proliferative Diabetic Retinopathy
As the condition progresses, it enters the moderate non-proliferative diabetic retinopathy stage. More retinal blood vessels become blocked or lose their ability to transport blood efficiently. This increased blockage leads to more bleeding and fluid leakage within the retinal tissue. Signs include cotton wool spots (damaged nerve fibers) and hard exudates (fatty deposits). Vision may begin to be affected, though changes are often mild.
Severe Non-Proliferative Diabetic Retinopathy
Severe non-proliferative diabetic retinopathy represents an advanced phase where many retinal blood vessels are blocked. This widespread blockage deprives larger areas of the retina of adequate blood supply, a condition known as ischemia. In response to this oxygen deprivation, the retina begins to release growth factors. These signals prompt the eye to grow new blood vessels, indicating a transition towards the most advanced stage. At this point, vision can be noticeably impaired.
Proliferative Diabetic Retinopathy
Proliferative diabetic retinopathy (PDR) is the most advanced stage, posing a serious threat to vision. The growth factors released by the oxygen-deprived retina trigger neovascularization, where fragile, abnormal new blood vessels grow. These new vessels often grow on the retina’s surface and can extend into the vitreous gel, the clear, jelly-like substance that fills the eye. These newly formed blood vessels are delicate and prone to breaking and bleeding.
Bleeding into the vitreous (vitreous hemorrhage) can cause sudden and severe vision loss, often appearing as dark, floating spots or streaks. The body’s attempt to heal these hemorrhages can lead to scar tissue formation. This scar tissue can contract and pull on the retina, potentially causing retinal detachment, where the retina separates from its underlying supportive tissue. Retinal detachment can result in permanent blindness if not treated promptly.