Visual evoked potentials in relation to visual acuity in macular disease

To investigate how central retinal function contributes to pattern visual evoked cortical potentials (PVECPs), we recorded transient and steady-state PVECPs in patients with macular disease and compared the results with those of patients with optic neuritis. The results were also evaluated for correlation with visual acuity and kinetic perimetric measurements.

PVECPs to 3 rev/s stimulation (transient) and 12 rev/s stimulation (steady-state) for check sizes 15' and 30' were obtained from all patients and age-matched healthy controls. The peak latency and amplitude of the P100 component of the transient VECP and the amplitudes of the steady-state VECP were measured and evaluated.

Patients with macular disease produced significant delay of P100 latency and amplitude attenuation of the steady-state VECP, as compared with healthy subjects. P100 latency delay was less in patients with macular disease than in those with optic neuritis, while the attenuation rate of the steady-state VECP amplitude was similar between groups. Visual acuity was correlated with P100 latency and steady-state VECP amplitude reduction.

Although the delay of latency was less in patients with macular disease than in those with optic neuritis, the electrophysiologic alterations that occur in macular disease demonstrate a potential for diagnostic value at the level of the retina.