![]() 1– 5 As well as clinical applications, the ability to measure pupillary sensitivity at many locations in the visual field provides a unique opportunity to explore the processing of visual stimuli that influence pupil responses. We have recently developed multifocal pupillographic objective perimetry (mfPOP), with which retinotopic loss or dysfunction of the visual system can be mapped through differences in the magnitude or time-course of dynamic pupil responses. Two protocols, utilizing low and high luminance-contrast plus color exchange, were identified as likely to incorporate both cortical and subcortical response components, and were deemed potential candidates for further investigation in clinical studies. Only the low luminance-contrast plus color exchange protocol differed significantly from the low luminance-contrast luminance protocol in both measures. The reverse pattern was observed between the equiluminant color exchange protocol and this same low luminance-contrast luminance protocol. Significant differences ( P < 0.05) in amplitudes but not delays were present between all three high luminance-contrast protocols and a low luminance-contrast luminance protocol, regardless of color content. Pupillary response amplitudes were more influenced by luminance-contrast than the color-contrast of stimuli response delays, however, were more closely linked to the proportion of color- versus luminance-contrast in each protocol. Test durations were 4 or 8 minutes therefore, estimated responses were derived from 60 or 120 stimulus presentations to each test region. Stimulus pulses were of 50 ms duration and were presented at mean intervals of 4 seconds/region. Forty-eight visual field test-regions (24/eye) were stimulated concurrently with uncorrelated sequences of either high or low luminance-contrast, luminance- plus color-contrast, or equiluminant color-exchange stimuli. Pupillary responses of 12 subjects were recorded to eight mfPOP stimulus variants (protocols). In this study, we investigate novel mfPOP stimuli designed to target neural components from either or both the sub-cortical pupillary luminance response and the cortically driven color response. We are developing multifocal pupillographic objective perimetry (mfPOP) to assess localized changes in function within visual pathways.
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