Electrophysiology: A review of signal origins and applications to investigating glaucoma

Because different electrophysiological responses can be isolated to different retinal and cortical cell types and levels, the proportion in which the different signals are reduced can reflect the primary areas of damage. The knowledge of electrophysiology component sources can thus be applied when examining ophthalmic disorders. The present review covers the proposed origins and the usefulness of the conventional electrophysiological responses. Their application to glaucoma is discussed, with particular reference to the pattern electroretinogram. In the second part of the current review, we present some recent developments that relate to the use of multifocal pseudorandomly stimulated recording. This technique enables a new approach to the electrical assessment of visual responses. Analysis for temporal non-linearities and spatial distribution of the response throughout the visual field can be implemented. This type of recording has the potential to provide a method of objective visual field assessment in glaucoma and other disorders of the visual system.