Electrodiagnostic methods in vision: Part 3. Clinical electrophysiology

Previously, we have discussed the clinical methods needed to obtain a flash electroretino-gram (ERG, Part I¹) and the sources of this waveform (Part 2²). In Part 3, we will describe the other techniques that can be used for electrodiagnostic evaluation of the visual system. Most of the techniques which are necessary to obtain a flash ERG are equally applicable to the other electrodiagnostic waveforms. In addition, we will discuss the nature of these waveforms, the methods needed to obtain them, pointing out any differences from the flash ERG. Finally, we will consider what is known about the generators of these signals. As these topics are complex, the nature of our coverage will be cursory and aimed at clinical applications.