Delayed visual evoked cortical potentials in retinal disease.

Flash and pattern visual evoked potentials (VEPs) were recorded in 16 patients with macular disease and in 3 patients with retinitis pigmentosa. Pathological VEP latencies were seen in 14 of the patients with macular lesions and in one with retinitis pigmentosa. Most eyes with a visual acuity below 0.2 showed delayed pattern responses. However, patients with higher visual acuity also had delayed pattern VEPs. It is concluded that an increase in VEP latency is not a specific sign of optic nerve lesion but may also occur in retinal disease, affecting different parts of the sensory retina.