Abstract

Since the Naka-Rushton eq was first shown to fit the change in trouh-to-peak b-wave amplitude with flash intensity^1,2, it has been fitted to b-wave data from a large number of patients. The parameters estimated from these fits, the semisaturation intensity (K) and the maximum response (V_max) are affected in different ways by different diseases. Fig. 1, from Birch et a1³, shows the deviations from the normal parameters for 41 patients with cone-rod dystrophy (CRD) or autosomal dominant retinitis pigmentosa (ADRP) retaining measurable rod ERGs. Each data point represents an individual patient and shows the change in log K and the change in log V_max from the log of the mean normal. Typical of diseases of the receptors, these patients show large changes

© 1993 Optical Society of America