Acute anterior and posterior ischemic optic neuropathy.

Criteria for diagnosis of acute ischemic optic neuropathy (acute ION) were proposed: acute ION was divided into two groups, ie, acute anterior ischemic optic neuropathy (acute AION) and acute posterior ischemic optic neuropathy (acute PION). Acute AION is characterized by pale or sometimes hyperemic papilledema in the early stage, followed by postneuritic optic atrophy. In contrast, acute PION shows normal optic disk in the early stage followed by development of simple optic atrophy. We analyzed 31 eyes of 24 cases with acute AION and 20 eyes of 18 cases with acute PION. The diagnostic criteria and clinical findings in both types were compared. Through analyses of the etiological factors, acute PION was thought to be acute retrobulbar optic neuritis caused by ischemic changes in the optic nerve. Laboratory examinations of serum lipids, hemostatic and fibrinolytic activities in cases of acute ION did not reveal significant differences from the findings in cases with retinal vein occlusion and diabetic retinopathy. In the early stage of acute ION, steroid therapy gave rise to some improvement of the visual function but showed no effect in the late stage of the disease.