Abstract

We use two noninvasive, psychophysical techniques to study the foveal cones of patients with retinitis pigmentosa. The techniques, steady-state color matching and dynamic color matching, are based on the fact that a color match depends on the optical density of the photopigment contained in the cones¹-⁴. Reduction of the number of cones or neural deficits will not affect the color match so long as the observer can do the task. These techniques provide estimates of 1) the optical density of the cones at a given retinal illuminance, 2) the illuminance that reduces optical density by half (the half-bleach illuminance or I_O), and 3) the rate of change in optical density³-⁴. To examine patients with minimal cone damage, we recruit patients in the early phases of disease with good visual acuity, 20/20-20/50. Patients, aged 14-46, vary as to the inheritance pattern and age of onset of night vision problems. All have reduced amplitude or extinguished photopic and scotopic ERG responses.

© 1986 Optical Society of America