Photopic flicker sensitivity losses in simplex and multiplex retinitis pigmentosa

Psychophysical tests for flicker sensitivity were conducted on a group of retinitis pigmentosa patients classed as either simplex or multiplex on the basis of the familial incidence of this disease. The results were compared with those obtained from normal observers. A similar pattern of losses, predominantly at high temporal frequencies, was shown by all patients. The pattern cannot be reproduced in normal observers by reducing the luminances of the test stimuli; nor can it be explained by a simple reduction in the signal-to-noise ratio of the visual system.