Higher-Order Kernel Responses of Human Electroretinogram Elicited by Full-Field Pseudorandom Flash Stimulus

Purpose: To observe higher-order kernel responses in human full-field electroretinograms (ERGs). Methods: A built-in light-emitting diode (LED) contact lens electrode and LED driver connected to the VERISTM system was used. The LED was driven by 18.75/second or 75/second base rate m-sequence stimuli to present 1-msec flashes (0.0025 to 10.0 cds/m²). Four individuals with normal vision served as subjects and their full-field pseudorandom ERGs (ffprERGs) were recorded. The first-order kernel (K1); the second-order kernel first slice (K2.1), second slice (K2.2), and third slice (K2.3); the third-order kernel first slice (K3.1); and the fourth-order kernel first slice (K4.1) were analyzed. Results: Each kernel response can be seen within 2 minutes of presenting stimuli at 75/second. Higher-order kernels converged more rapidly after stimuli presented at 18.75/second. Stimulus intensities less than 0.01 cds/m² evoked only sluggish K1 responses to stimuli presented at 75/second. Conclusions: ffprERGs illustrate the basic aspects of higher-order kernels without stray light effects. In order to verify the clinical utility of higher-order kernels in multifocal ERGs (mfERGs), ffprERGs should be evaluated in individuals with disorders that affect broad areas of the retina.