[Reaching Beyond the Retina with Clinical Electrophysiology]

Electrophysiological recordings from the retina and cortex are pivotal to reach beyond the retina for ophthalmological and neuro-ophthalmological diagnostic testing. Pattern electroretinograms (PERG) can be used to examine retinal ganglia cells and visual evoked potentials (VEP) help to investigate overall visual pathways. Thus, they support objective functional tests of visual pathways, as well as differential diagnosis. Conventional electrophysiology is of limited value in detecting local defects in the visual field. This gap is filled by applications of multifocal electrophysiology. This permits spatially resolved testing with multifocal PERG (mfPERG) and multifocal VEP (mfVEP), and eventually objective visual field testing with mfVEP. It is important for this spectrum of methods to consider possible confounds when performing the measurements and when interpreting the results. This is explained in the present article on the basis of a series of typical examples.