Electrophysiological findings in anterior ischemic optic neuropathy

Electroretinograms (ERG), oscillatory potentials (OP) and pattern reversal visual evoked potentials (VEP) were performed in nine patients (mean age 66 years) with unilateral long-standing anterior ischemic optic neuropathy (AION) and in an age matched control group. Normal ERGs but bilateral impaired OPs were observed in virtually all AION affected patients. Regardless of visual acuity, VEP amplitude reduction was found in all eyes with AION and in controlateral eyes of patients with associated systemic conditions such as diabetes mellitus, arterial hypertension and atherosclerosis. A normal latency of VEP was found bilaterally in AION affected patients; however no correlation between VEP latency and visual acuity or fields could be established. Our results seem to indicate moderate ischemic damage to the retina and to the axons of the optic pathways in patients with AION.