Best diabetologist near me Diabetic retinopathy progresses through four stages: Mild Non-Proliferative Retinopathy: Small bulges (microaneurysms) form in the blood vessels of the retina. These may leak fluid or blood. Moderate Non-Proliferative Retinopathy: Blood vessels become more damaged and may swell or become blocked. Severe Non-Proliferative Retinopathy: Many blood vessels are blocked, leading to areas of the retina receiving insufficient blood. Proliferative Diabetic Retinopathy: Abnormal blood vessels grow on the retina or into the vitreous (gel-like substance in the eye). These vessels can bleed, cause scarring, or lead to retinal detachment.