Axonal loss in a patient with anterior ischemic optic neuropathy as measured with scanning laser polarimetry.

PURPOSE To report Nerve Fiber Analyzer (NFA/GDx; Laser Diagnostic Technologies, San Diego, California) measurements in a patient during the early phase of an anterior ischemic optic neuropathy. METHODS Case report. A 58-year old man with acute anterior ischemic optic neuropathy had repeated NFA/GDx scans of the nerve fiber layer adjacent to the optic nerve head of the involved eye, as well as repeated HFA 30.2 (Humphrey Field Analyzer; Humphrey Systems, San Leandro, California) visual field examinations. RESULTS At presentation (day 0), he had a normal superior nerve fiber bundle on the NFA/GDx, with a deep inferior hemifield scotoma. By day 21 and day 36, the superior nerve fiber bundle thinned on the NFA/GDx, whereas the scotoma remained practically unchanged. CONCLUSION These findings suggest that after the onset of an anterior ischemic optic neuropathy, acute loss of axonal function results in scotoma, presumably from ischemia. This is followed by a gradual disappearance of nerve fiber tissue, as measured with the NFA/GDx, within several weeks.