Posterior Ischemic Optic Neuropathy

Posterior ischemic optic neuropathy (PION) is one of the rare optic neuropathies that occurs as a result of hypoperfusion of the optic nerve posterior to the optic nerve head. It usually causes acute, painless vision loss, and no features are detected at the optic nerve head during fundus examination. PION is a multifactorial disease that combines vascular and local risk factors, develops on the basis of various systemic diseases, and is accompanied by inadequate autoregulation in the optic nerve. Etiologically; it is divided into three subtypes: nonarteritic PION, which develops on the basis of vascular disease, arteritic PION, which is associated with giant cell arteritis (GCA), and perioperative PION, which occurs after surgical procedures. Diffusion restriction can be detected in the acute phase with diffusion-weighted magnetic resonance (MR) imaging. Diffusion MRI can be considered as the first technique to diagnose PION by identifying acute ischemic lesions of the optic nerve. Since there is no effective treatment method that can reverse vision loss, steroid treatment should be started immediately when the diagnosis of GCA is considered, and surgical risk factors such as anemia, hypovolemia, and hypotension should be corrected quickly and effectively in the perioperative period and the disease should be prevented before it occurs.