Electrodiagnostic methods in vision: Part 2. Origins of the flash ERG

In Part 1¹ of this review, we described the methods to acquire electrodiagnostic signals and the nature of the flash ERG, as it is a common waveform used in clinical applications.¹ We also provided guidelines to the protocols and clinical procedures needed to evaluate retinal function.¹ In Part 2, we will discuss what is known of the retinal generators (sources) that give rise to the current flows within the retina following light stimulation and that underlie the various waveforms that comprise the flash ERG. A complete understanding of these processes requires a good grasp of retinal physiology. Those not familiar with retinal physiology are referred to a previous review carried by this journal on this topic.^2–4.