Visual Electrophysiology Made Simple for the Postgraduates
Visual electrophysiology is an extremely useful tool to study the retinal function objectively. It assesses the functional aspects of not only the retina but also the visual pathway as a whole. Even in this era of advanced imaging, one cannot ignore the importance of the functional aspects of the cellular network in the retina. The commonly used tests with their salient applications are enumerated in Table 1. S.no Test Application 1. Electroretinogram(ERG) Elicits mass response from the Retina 2. Electro-oculogram(EOG) Assesses the function of the Retinal pigment epithelium 3. Pattern ERG(PERG) Differentiates macular and optic nerve pathology 4. Multifocal ERG(MfERG) Picks up focal retinal pathology and maps out the topography 5. Photopic Negative Response(PhNR) Tests the function of retinal ganglion cells 6. Visual Evoked Potentials(VEP) Assesses the visual pathway up to the occipital cortex 7. Multifocal VEP(MfVEP) Picks up focal dysfunction of the visual pathway and maps the topogra

