Abstract

The b-wave of the ERG has been used as a measure of the activity of the inner nuclear layer. Fulton and Rushton¹ recorded human ERGs elicited by flashes of different intensities and fitted their data with the function where R is the trough-to-peak amplitude of the b-wave, R_m is the maximum amplitude, I is the flash intensity, and K is the semisaturation intensity. They observed that light adaptation changed the values of K and R_m and associated these changes with modification in "the b-wave generating mechanism". Arden et al² extended this analysis to retinal disease by measuring response-intensity functions in patients and relating changes in K and R_m to the action of a disease at the receptors and/or "the b-wave generating mechanism". Since this study, hundreds of response-intensity functions have been collected in the clinic and the parameters K and R_m estimated.³⁻⁹ The solid curves in Fig. 1A show three ERG responses from a typical response-intensity series.⁷ The filled circles in Fig. 1B show the trough-to-peak b-wave amplitudes for the complete data set. The solid curve in Fig. 1B is the best fit of eq. 1 to the b-wave amplitudes.

© 1991 Optical Society of America