The study of the electrical response of the retina to a luminousstimulus is one of the main ﬁelds of research in ocular electrophysiology. Thefeatures of the ﬁrst component (a-wave) of the retinal response reﬂect thefunctional integrity of the two populations of photoreceptors: rods and cones. Weﬁt the a-wave for pathological subjects with functions that account for possiblemechanisms governing the kinetics of the photoreceptors. The paper extends aprevious analysis, carried out for normal subjects, in which both populations areactive, to patients aﬀected by two particular diseases that reduce the workingpopulations to only one. The pathologies investigated are Achromatopsia, acone disease, and Congenital Stationary Night Blindness, a rod problem. Wepresent evidence that the analysis of a pathological a-wave can be employed toquantitatively measure either cone or rod activities and to test hypotheses abouttheir responses. The results show that the photoreceptoral responses diﬀer in thetwo cases and functions implying a diﬀerent number of photocascade stages arenecessary to achieve a correct modeling of the early phototransduction process.Numerical values of the parameters characterizing the best-ﬁt functions are givenand discussed.
|Numero di pagine||11|
|Rivista||Journal of Statistical Mechanics: Theory and Experiment|
|Stato di pubblicazione||Published - 2009|
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