Characterization of multi-input electroretinogram using normal control subjects.

BACKGROUND

The multi-input electroretinogram (ERG) has recently been developed to analyze focal retinal responses in the central region and is expected to become a powerful tool for management of retinal diseases. The relationship between the obtained ERG response and retinal neuronal functions is not yet fully understood.

METHOD

In the present study, in order to study the spatial retinal functions; multi-input ERGs were recorded from 14 healthy subjects under several illumination conditions modulating photoreceptor functions.

RESULTS

The first-order kernel amplitudes were changed in correspondence to the cone photoreceptor adaptation states under different background illuminations. A strong flash exposure significantly lowered the amplitude (approximately 70%) within the central 15 deg but lowered it only slightly (10-20%) in the peripheral areas outside the central 15 deg. Similar effects were observed when the stimulus luminance was lowered by neutral density filters.

CONCLUSION

Our data suggest that a newly developed multi-input measurement of ERGs represents signals within the firing of postreceptor neurons from cone photoreceptors at specific areas. Thus, this analysis is a useful tool for mapping the spatial network of neurons in the central region.