Diabetic retinopathy is classified as either nonproliferative (background) or proliferative. Nonproliferative retinopathy is the early stage, where small retinal blood vessels break and leak. In proliferative retinopathy, new blood vessels grow abnormally within the retina. This new growth can cause scarring or retinal detachment, which can lead to vision loss. The new blood vessels may also grow or bleed into the vitreous humor, the transparent gel filling the eyeball in front of the retina. Proliferative retinopathy is much more serious than the nonproliferative form and can lead to total blindness.