Pattern visual evoked cortical potentials in patients with toxic optic neuropathy caused by toluene abuse.

PURPOSE Electrophysiological evaluation of the visual function of patients with toxic neuropathy caused by toluene abuse. METHODS Fifteen patients (mean age 25.6 years, eight men and seven women) were diagnosed with bilateral optic neuropathy. Pattern visual evoked cortical potentials (PVECPs) and clinical symptoms were investigated. RESULTS Visual acuities at the initial visit were less than 0.1 in 5 cases and 0.1-1.0 in 10 cases. PVECPs were followed up in the 15 cases. At the first recording, PVECPs were nonrecordable in both eyes of 11 cases, the P100 peak latency was prolonged in both eyes of 3 cases, and only 1 case showed a normal P100 peak latency. After treatment, visual acuities improved more than 2 lines in 6 cases, 3 of whom showed normal P100 peak latency in the PVECPs. Visual prognosis and PVECP changes were identical in both eyes of all patients. CONCLUSIONS In patients with toluene optic neuropathy, the P100 peak latency of PVECP shortened as visual acuity improved. The VECP abnormalities in these patients suggest that there is a severe effect on the optic nerve after prolonged exposure to toluene.