Biomarkers of lesion severity in a rodent model of nonarteritic anterior ischemic optic neuropathy (rNAION)

The rodent model of nonarteritic anterior ischemic optic neuropathy (rNAION) is similar in many its pathophysiological responses to clinical NAION. Like human NAION, there significant variability the severity lesion produced, and little known parameters associated with rNAION induction or if pre- early post-induction biomarkers can be identified that enable prediction ultimate loss retinal ganglion cells (RGCs). Adult male Sprague-Dawley outbred rats were evaluated for various including physiological characteristics (heart rate, respiratory temperature, hematocrit [Hct]), nerve head (ONH) appearance, mean diameter, intravenous fluorescein indocyanine green angiographic patterns vascular leakage at 5 hours post-induction, performed using a spectral domain-optical coherence tomography (SD-OCT) instrument. Early changes correlated RGC by Brn3a (+) immunohistology. also was relative level laser exposure. ONH edema 2d, but not 5hr, post most closely degree loss, revealing threshold effect, consistent compartment syndrome where minimum capillary compression within tight space responsible damage. increased dramatically as exposure increased. Neither nor 5hr informative loss. Similar exhibits marked severity. Unlike pre-induction diameter likely does contribute severity; however, cross-sectional used biomarker 2d determine randomization subjects prior inclusion specific neuroprotection neuroregeneration studies.