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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nonarteritic anterior ischemic optic neuropathy (NAION) results from isolated anterior optic nerve (ON)-axonal ischemia near the retina-optic nerve junction. We utilized a rodent model of NAION (rAION) to study the in vivo inflammatory response after pure axonal ischemic infarct. ON ischemia was generated using laser-coupled rose Bengal dye photoactivation, and the infarct localized using tetrazolium red and histology. ON inflammation was evaluated following infarct using extrinsic macrophage (ED1) and microglial (isolated Iba1) cell markers. In naive ONs, some ED1(+)/Iba1(+) cells, representing extrinsic macrophages, were present in intraretinal ON region, but not in the retroscleral (isolated ON) region. Numerous ED1(-)/Iba1(+) cells, likely representing intrinsic microglia, were present throughout the entire ON. One day post-stroke, slight increases in both ED1(+) and Iba1(+) cells were apparent in the eye region immediately surrounding the anterior ON. Three days post-stroke, there was marked infiltration and aggregates of ED1(+)/Iba1(+) cells, with axon structural disruption in the region of the ischemic infarct. ED1(+) and Iba1(+) cells were present in the portion of the ON surrounding the infarct, possibly representing a penumbral region similar to that seen in ischemic brain infarcts. Although ED1(+) cells decreased by 7-14 days post-stroke, large numbers of Iba1(+) cells persisted in the anterior ON. Similar to other CNS ischemic strokes, pure axonal ischemia results in the early recruitment of extrinsic macrophages to the ischemic region. Manipulation of the inflammatory response may be an important variable that could potentially improve visual outcome.
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PMID:Optic nerve infarction and post-ischemic inflammation in the rodent model of anterior ischemic optic neuropathy (rAION). 1940 Nov 81

Nonarteritic anterior ischemic optic neuropathy (NAION) is a focal ischemic lesion of the optic nerve that affects 1/700 individuals throughout their lifetime. NAION results in optic nerve edema, selective loss of the retinal ganglion cell neurons (RGCs) and atrophy of the optic nerve. A rodent model of NAION that expresses most NAION features and sequelae has been developed, which is applicable to both rats and mice. This model utilizes a focal laser application of 532 nm wavelength to illuminate a photoactive dye, Rose Bengal (RB), to cause capillary damage and leakage at the targeted anterior optic nerve (the laminar region). After rNAION induction, there is an early optic nerve ischemia, optic nerve edema, and intraneural inflammation, followed by selective RGC and axonal loss. Since the optic nerve is a CNS white matter tract, the rNAION model is applicable to mechanistic studies of selective white matter ischemia, as well as neuroprotective analyses and short and long-term mechanisms of glial and neuronal response to ischemia.
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PMID:The Rodent Model of Nonarteritic Anterior Ischemic Optic Neuropathy (rNAION). 2791 58

Shock-induced anterior ischemic optic neuropathy (SIAION) is a known type of optic neuropathy in patients who experienced shock related to different etiologies such as anemia and severe intradialytic hypotension like in our patient. Nonarteritic anterior ischemic optic neuropathy (NAION) is the most common acute unilateral known type of optic neuropathy in older patients with vasculopathic risk factors such as hypertension, diabetes mellitus, and obstructive sleep apnea. Although SIAION and NAION are similar optic neuropathies due to ischemia and, in particular, hypotension, they may have different pathogenic mechanisms (e.g., acute shock or intradialytic hypotension vs nocturnal hypotension), laterality (e.g., unilateral vs bilateral), and severity (e.g., light perception or worse vision). We presented a case with restricted diffusion on the apparent diffusion coefficient and the diffusion weighted imaging confined to the optic disc head in a patient with pallid edema after intradialytic hypotension. Although DWI of the optic nerve is neither 100% specific nor 100% sensitive for ischemia, we believe that restricted diffusion of the optic nerve head in our case is a clinico-radiologic correlate to pallid edema in SIAION.
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PMID:Restricted Diffusion in the Optic Nerve Head After Shock-Induced Anterior Ischemic Optic Neuropathy. 3202 50