The use of multifocal electroretinograms and multifocal visual evoked potentials in optic nerve disorders

Abstract

The multifocal electroretinogram (mfERG) and multifocal visual evoked potential (mfVEP) techniques allow for the simultaneous recording of local responses from many regions of the visual field. This chapter provides an introduction to these techniques and focuses, in particular, on the use of these techniques to rule out retinal causes of visual abnormalities and to diagnose optic nerve disorders. The mfERG and mfVEP techniques are not useful in the following clinical situations: (1) the standard full-field ERG and VEP tests provide adequate data; (2) the defect is in the far periphery; (3) the problem likely involves the rod system; or (4) the patient cannot fixate reliably. However, in patients with steady fixation and localized visual field defects, the mfERG and mfVEP are helpful in diagnosing optic nerve disorders when interpreted with the patient's visual field and/or OCT imaging.