It is a complication of diabetes and is caused by the deterioration of blood vessels which nourish the retina at the back of the eye. These damaged blood vessels may leak fluid or blood. When bleeding occurs in retinopathy, the patient has hazy or complete loss of sight. Though there is no symptom of pain, this severe form of diabetic retinopathy requires immediate medical attention.

The most significant treatment is laser photocoagulation. Even in advanced stages of the disease, it can reduce the chance that a patient will have severe visual loss. However, laser photocoagulation cannot be used on all patients, depending on the location , extent and if the vitreous is too clouded with blood.