Pupillometer-Based Objective Chromatic Perimetry in Normal Eyes and Patients With Retinal Photoreceptor Dystrophies

Abstract

Citation: Skaat A, Sher I, Kolker A, et al. Pupillometer-based objective chromatic perimetry in normal eyes and patients with retinal photoreceptor dystrophies. Invest Ophthalmol Vis Sci. 2013;54;2761 -2770 . DOI:10.1167 PURPOSE. To evaluate a novel objective perimetry using multifocal chromatic pupil light reflex in normal participants and patients with photoreceptor dysfunction, and to relate this new technique with subjective dark-adapted chromatic Goldmann perimetry.METHODS. Thirty-two eyes of 17 retinitis pigmentosa (RP) or cone-rod dystrophy patients and 20 eyes of 12 healthy individuals were tested. A computerized infrared video pupillometer was used to record changes in pupil diameter in response to short-and long-wavelength stimuli (peak 485 and 640 nm, respectively; light intensity 40 cd/m 2 ) at 13 different points of the 308 visual field (VF), under background illumination of 2.7 cd/m 2 . The pupillary response (PR) of patients was compared with PR obtained from normal control participants. In 11 patients, the pupillary responses were also compared with their findings on dark-adapted chromatic Goldmann perimetry. RESULTS.Significantly reduced pupillary responses were obtained in RP patients in response to the short-wavelength stimulus in nearly all perimetric locations (P < 0.03). By contrast, in response to the long-wavelength stimulus, RP patients demonstrated significantly reduced PR mostly in peripheral locations (P 0.02). In a cone-rod dystrophy patient, the PR to both long-and short-wavelength stimuli was significantly lower in the scotoma area identified by the dark-adapted chromatic Goldmann perimetry. In all patients that were tested by the chromatic Goldmann, minimal PR was recorded in areas that were nondetected in the chromatic Goldmann perimetry.CONCLUSIONS. This study demonstrates the potential feasibility of using pupillometer-based chromatic perimetry for objectively assessing VF defects and retinal function in patients with retinal dystrophies. (ClinicalTrials.gov number, NCT01021982.)

Naturally-occurring myopia and loss of cone function in a sheep model of achromatopsia

“…Using this methodology, it has been shown that in Leber's Congenital Amaurosis patients there is selective loss of PLR in response to dim blue light, but not in response to bright red or blue light, demonstrating selective loss of rod function 28 . Similar results were obtained in retinitis pigmentosa patients 26,29 . Conversely, loss of PLR in response to bright red light, but not to dim or bright blue light, has been demonstrated in achromatopsia patients 24,30 .…”

“…in humans and animal models, using red and blue light stimulation of varying intensities delivered by Ganzfeld 25 , multifocal Ganzfeld 26 , or diode-based light 27 . Using this methodology, it has been shown that in Leber's Congenital Amaurosis patients there is selective loss of PLR in response to dim blue light, but not in response to bright red or blue light, demonstrating selective loss of rod function 28 .…”

Effect of Stimulus Intensity and Visual Field Location on Rod- and Cone-Mediated Pupil Response to Focal Light Stimuli

“…Our findings are supported by previous studies in patients with RP, a disease that predominantly affects the rods, demonstrating a milder defect in PLR for focal red stimuli compared with blue stimuli and nearly normal PLRs for red light stimuli presented at the center of the VF under mesopic conditions in RP patients. 18,22 By contrast, under blue light background conditions, our results suggest that the cones are the main mediators of the PLR for focal red and blue stimuli. This conclusion is based on the findings that the PLRs for blue and red light stimuli were approximately the same across the luminance range tested in the peripheral VF, and at light intensities 2 log cd/m 2 in the central VF.…”

Blue Multifocal Pupillographic Objective Perimetry in Glaucoma

“…aimed to determine whether improvements could be made to methods currently being developed by targeting the intrinsic component of the ipRGC response. Pupil perimetry using single blue stimuli have been undertaken 47,48 ; however, these studies used dark-adapted subjects, so responses will have also involved rod photoreceptors. The use of a photopic blue adapting background in this experiment aimed to minimize rod involvement and facilitate the observation of melanopsin responses.…”