Intensity Dependence of cGMP Models Applied to A-Wave Leading Edge

Two quantitative models of the cGMP phototransduction cascade have been proposed based on studies of the photocurrent response in isolated amphibian rods (Cobbs and Pugh, 1987; Lamb and Pugh, 1991). These models, when fitted to photocurrent data, provide estimates of rate parameters of the cGMP cascade. Application of such quantitative models to a-wave data of the ERG can, in principle, provide information equivalent to that obtained from isolated rods at the biochemical level on photoreceptor function in vivo. Information at this biochemical level has not been obtained previously from corneal ERG recordings and has the potential to provide a basis for new, more fundamental, understanding of retinal disease processes affecting both photoreceptor and inner retinal elements.