Comparative studies on pattern VECP between patients with ischemic optic neuropathy and optic neuritis.

PURPOSE: To evaluate whether and how VECPs are useful in differentiating ION from ON.

METHODS

We retrospectively studied 27 patients with non-arteritic ION and 69 patients with ON using pattern visually evoked cortical potentials (PVECPs) to 3 rev/sec stimulation (transient) and 12 rev/sec stimulation (steady-state).

RESULTS

In patients with ION, non-recordable responses were found in 25% of those with transient VECP and in 74% of those with steady-state VECP. In ON patients, non-recordable responses were found in 34% of those with transient VECP and in 64% of those with steady-state VECP. The average peak latency of P100 component in those with ION was significantly shorter than in those with ON. The amplitude ratio (affected eye/fellow eye) of steady-state VECP was significantly higher in those with ION than in those with ON. The amplitude ratio of P100 showed no significant differences between groups.

CONCLUSION

The P100 peak latency of transient VECPs and the amplitude of steady-state VECPs have the potential to differentiate between ION and ON.