Simultaneous recording of pattern electroretinogram and visual evoked responses in neuro-ophthalmologic disorders

Simultaneous pattern electroretinograms (P-ERG) and pattern visual evoked potentials (P-VEP) to transient and steady-state checkerboard pattern reversal were recorded in 52 normal volunteers. Twenty-seven patients were also studied. Three patterns of abnormalities emerged. Pattern 1 with prolonged P-ERG, prolonged P-VEP, and normal retino-cortical time (RCT) was found exclusively in early maculopathies. Pattern 2 with normal P-ERG, prolonged P-VEP, and prolonged RCT was found in optic nerve lesions without optic atrophy, probably indicating the presence of a demyelinating lesion of the optic nerve. Pattern 3, with very small or absent P-ERG and P-VEP, was observed in both maculopathies and optic atrophies.