Patel Hershel R, Margo Curtis E
From the Departments of Ophthalmology (Drs Patel and Margo), Pathology and Molecular Biology (Dr Margo), Morsani College of Medicine, University of South Florida, Tampa.
Arch Pathol Lab Med. 2017 Jan;141(1):162-166. doi: 10.5858/arpa.2016-0027-RS.
Ischemic optic neuropathy (ION) describes a state of hypoxic injury of the optic nerve. Clinically, ION is divided into anterior and posterior forms defined by the presence or absence of optic disc swelling, respectively. It is further classified as arteritic when secondary to vasculitis, and nonarteritic when not. The site of vascular occlusion for anterior ION from giant cell arteritis is the short posterior ciliary arteries, but mechanical vascular obstruction does not play a role in most nonarteritic cases. Histologically, ION is characterized by axon and glial necrosis, edema, and a sparse mononuclear response. Like other ischemic injuries, the morphologic alternations in the nerve are time dependent. A variant of ION called cavernous degeneration (of Schnabel) features large cystic spaces filled with mucin. Several conditions can histologically mimic cavernous degeneration of the optic nerve. The scarcity of cases of ION examined histologically has contributed to an incomplete understanding of its pathogenesis.
缺血性视神经病变（ION）描述了视神经的缺氧损伤状态。临床上，ION分为前部和后部形式，分别由视盘肿胀的有无来定义。继发于血管炎时进一步分类为动脉炎性，否则为非动脉炎性。巨细胞动脉炎导致的前部ION的血管阻塞部位是睫状后短动脉，但在大多数非动脉炎性病例中，机械性血管阻塞不起作用。组织学上，ION的特征是轴突和胶质细胞坏死、水肿以及稀疏的单核反应。与其他缺血性损伤一样，神经的形态学改变与时间有关。ION的一种变体称为（施纳贝尔）海绵状变性，其特征是充满粘蛋白的大囊腔。有几种情况在组织学上可模拟视神经的海绵状变性。经组织学检查的ION病例稀少，这导致对其发病机制的理解不完整。
