The patient of this study is a protanope who is afflicted with retinitis pigmentosa. As with other patients studied, an abnormality in Stiles’s pi-1 mechanism was found in the patient’s worse eye (20/35 visual acuity). From his rejection of monochromatic color matches, we inferred that the sensitivity of the short-wave cones is reduced, but their signals are not abnormally attenuated by the middle-wave cones. The patient’s pi-4 thresholds, however, were within the range of normal control values.
© 1982 Optical Society of America
Rockefeller S. L. Young, "Early-stage abnormality of foveal pi mechanisms in a patient with retinitis pigmentosa," J. Opt. Soc. Am. 72, 1021-1025 (1982)