They are secondary to severe and prolonged ipsilateral stenosis of the extracranial internal carotid artery or the common carotid artery. Occasionally, it has been associated with occlusion of the ophthalmic artery.

Treatment: Quick determination of the cause can lead to urgent measures to save the eye and the life of the patient. Vision loss and pain in patients with atherosclerosis, deep vein thrombosis, atrial fibrillation, pulmonary thromboembolism, or other previous embolic events. Digital massage, 500 mg IV acetazolamide and 100 mg of methylprednisolone IV, additional measures include aqueous humor paracentesis to decrease acute IOP and an Erythosedimentation, should be done to detect it. Improvement can be determined by visual acuity, visual field tests, and by ophthalmoscopic examination. At a later stage, pan-retina photocoagulation with an argon laser appears to be effective in reducing neovascular components and their sequelae.