Diabetes damages small blood vessels throughout the body, leading to reduced blood flow. When these changes affect the tiny blood vessels in the eyes, diabetic retinopathy may develop.

In the early stage of diabetic retinopathy, tiny blood vessels in the eye weaken and develop small bulges that may burst and leak into the retina. Later, new fragile blood vessels grow on the surface of the retina. These blood vessels may break and bleed into the eye, clouding vision and causing scar tissue to form.

The scar tissue may pull on the retina, leading to retinal detachment. Retinal detachment occurs when the two layers of the retina become separated from each other and from the wall of the eye. This can lead to vision loss.