Purpose: To demonstrate the effects of optic nerve ischemia on retinal nerve fiber layer (RNFL) and the associated visual dysfunction.Methods: 23 patients (25 eyes) with anterior ischemic optic neuropathy (AION) underwent fundus fluorescein angiography (FFA), and then red-free light pictures were taken via SE-40 exceiter filter. All pictures were printed for RNFL analysis. Humphrey central field analysis was conducted. All data obtained from FFA and visual field defects were analysed statistically.Results: The RNFL defects and the corresponding visual field defects were presented in 23 of 25 eyes (92%). The optic disc filling defects, RNFL defects and visual field defects were found to be highly correspondent to each other. The RNFL defects were mainly the local losses of RNFL which were correspondent to the ischemic regions.Conclusion: The poor optic disc filling or ischemia can result in the RNFL defects which cause the associated visual dysfunction. Because RNFL defects are irrever-siable changes, th Purpose: To demonstrate the effects of optic nerve ischemia on retinal nerve fiber layer (RNFL) and the associated visual dysfunction. Methods: 23 patients (25 eyes) with anterior ischemic optic neuropathy (AION) underwent fundus fluorescein angiography (FFA), and then All pictures were printed for RNFL analysis. Humphrey central field analysis was conducted. All data obtained from FFA and visual field defects were analyzed. Results: The RNFL defects and the corresponding visual field defects were presented in 23 of 25 eyes (92%). The optic disc filling defects, RNFL defects and visual field defects were found to be highly correspondent to each other. The RNFL defects were mainly the local losses of RNFL which were correspondent to the ischemic regions. Confound: The poor optic disc filling or ischemia can result in the RNFL defects which cause the associated visual dysfunction. Because RNFL defects are irreversible siable changes, th