[Research advances in the risk factors of nonarteritic anterior ischemic optic neuropathy].

As the most common acute optic neuropathy among individuals who are over 50-year old,non arteritic anterior ischemic optic neuropathy ( NAION) is presumed result from a circulatory insufficiency,or infarct, within the lamina or retrolaminar portion of the optic nerve head that is supplied by the short posterior ciliary arteries. It usually presents with sudden painless unilateral visual loss, characterized visual field defects, relative afferent papillary defect and pallid optic disk edema. The exact etiology of NAION remains elusive. Although numerous risk factors have been proposed, most of them are controversial. We summarized all these risk factors in this review.