Purchase this article with an account.
J. D. Sinclair, S. C. Anderson, R. H. Kardon; Abnormal Transient and Sustained Pupil Contractions to Chromatic Stimuli in Patients With Photoreceptor Disease Correlate With the Physiologic Response Properties of Melanopsin Containing Retinal Ganglion Cells. Invest. Ophthalmol. Vis. Sci. 2007;48(13):5535.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To characterize the effect of human photoreceptor disease on the transient and sustained pupil contractions in response to luminance matched red and blue light as a function of brightness. This was done to differentiate photoreceptor mediated pupil responses from those assumed to be due to intrinsic, direct light-activation of melanopsin containing retinal ganglion cells.
The pupil responses of 13 patients with photoreceptor disease (X-linked RP, N=1; Autosomal Recessive RP, N=7; Rod-Cone Dystrophy, N=5) were compared to 10 normal subjects recorded by infrared computerized pupillography (Arrington Research Inc). Two stimulus wavelengths consisting of equal luminance red (600-620nm band) and blue (465-485nm) light were presented in a Ganzfeld bowl (Diagnosys Inc) with 10 second duration steps of 1, 10, and 100 cd/m2 to each eye.
In eyes with photoreceptor disease, there was a relative decrease in the amplitude of the transient pupil responses at low and medium intensities (1cd/m2 and 10cd/m2) to both red and blue light stimuli. At the 100 cd/m2 bright light intensity the blue light stimulus elicited a normal or near normal sustained pupil contraction, in spite of reduction in red light elicited pupil contraction. In addition, pupil dilation after termination of the 10 second duration 100 cd/m2 light was often slower after blue light stimulation, compared to red light stimulation.
In eyes with photoreceptor disease, there appears to be a relative decrease in the transient pupil response, indicating that the initial transient component of pupil contraction is likely to be mediated by photoreceptors in humans. Rapid pupil dilation after termination of light appears to be mediated by a light off signal from photoreceptors, inhibiting the melanopsin retinal ganglion cell’s sustained firing on the pupil light reflex. Loss of cones causes slowed pupil dilation after a bright blue light stimulus is terminated.
This PDF is available to Subscribers Only