Establishing a normative database for quantitative pupillometry in the pediatric population

Shah, Sanket; Ranaivo, Hantamalala Ralay; Mets-Halgrimson, Rebecca; Rychlik, Karen; Kurup, Sudhi P.

doi:10.1186/s12886-020-01389-x

Cited by 17 publications

(14 citation statements)

References 18 publications

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“…Regarding latency, we note that the PyPlr data were collected on a Windows laptop and therefore that they include on average ~59 ms timestamping error (corresponding to the average difference between the World and Eye camera timestamps in Figure 4 for OS = Windows | FPS = 120). Subtracting 59 ms from the averages for Subjects 1, 2 and 3 gives values of 242 ms, 250 ms and 226 ms, respectively, which are more plausible with respect to normative values in the literature (e.g., Shah et al, 2020;Straub et al, 1992;Winston et al, 2019).…”

Section: System For Researching the Pupil Light Reflex 28supporting

confidence: 50%

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

Martin

Pinto

Bulte

et al. 2021

Preprint

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We introduce PyPlr—a versatile, integrated system of hardware and software to support a broad spectrum of research applications concerning the human pupillary light reflex (PLR). PyPlr is a custom Python library for integrating a research-grade video-based eye-tracker system with a light source and for streamlining stimulus design, optimisation and delivery, device synchronisation, and extraction, cleaning, and analysis of pupil data. We additionally describe how full-field, homogenous stimulation of the retina can be realised with a low-cost integrating sphere that serves as an alternative to a more-complex Maxwellian view setup. Users can integrate their own light source, but we provide full native software support for a high-end, commercial research-grade 10-primary light engine which offers advanced control over the temporal and spectral properties of light stimuli as well as spectral calibration utlities. Here, we describe the hardware and software in detail and demonstrate its capabilities with two example applications: 1) pupillometer-style measurement and parametrisation of the PLR to flash of white light, and 2) comparing the post-illumination pupil response (PIPR) to flashes of long and short-wavelength light. The system holds promise for researchers who would favour a flexible approach to studying the PLR and the ability to employ a wide range of temporally and spectrally varying stimuli, including simple narrowband stimuli.

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Section: System For Researching the Pupil Light Reflex 28supporting

confidence: 50%

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

Martin

Pinto

Bulte

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…4 for OS = Windows | FPS = 120). Subtracting 59 ms from the averages for Subjects 1, 2 and 3 gives values of 242 ms, 250 ms and 226 ms, respectively, which are more plausible with respect to normative values in the literature (e.g., Shah et al, 2020 ; Straub et al, 1992 ; Winston et al, 2019 ). For the 75% metric, the discrepancy may be explained by geometrical differences in retinal stimulation: Although the stimuli were matched for a -opic irradiance and delivered monocularly, the PLR-3000 light stimulus comes from 4 small LEDs positioned close to the eye, whereas our integrating sphere system stimulates the entire visual field with reflected light.…”

Section: Methodsmentioning

confidence: 54%

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

et al. 2021

View full text Add to dashboard Cite

We introduce PyPlr—a versatile, integrated system of hardware and software to support a broad spectrum of research applications concerning the human pupillary light reflex (PLR). PyPlr is a custom Python library for integrating a research-grade video-based eye-tracker system with a light source and streamlining stimulus design, optimisation and delivery, device synchronisation, and extraction, cleaning, and analysis of pupil data. We additionally describe how full-field, homogenous stimulation of the retina can be realised with a low-cost integrating sphere that serves as an alternative to a more complex Maxwellian view setup. Users can integrate their own light source, but we provide full native software support for a high-end, commercial research-grade 10-primary light engine that offers advanced control over the temporal and spectral properties of light stimuli as well as spectral calibration utilities. Here, we describe the hardware and software in detail and demonstrate its capabilities with two example applications: (1) pupillometer-style measurement and parametrisation of the PLR to flashes of white light, and (2) comparing the post-illumination pupil response (PIPR) to flashes of long and short-wavelength light. The system holds promise for researchers who would favour a flexible approach to studying the PLR and the ability to employ a wide range of temporally and spectrally varying stimuli, including simple narrowband stimuli.

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“…These changes with age are fairly correlated with changes in eye size but may also be influenced by developmental changes of the pupillary reflex. 1,5 In the study by Brown et al, there were also significant differences in pupil size and maximum constriction velocity when comparing healthy black to their respective white cohorts. Our results also reflect a variation amongst races as our data showed no significant change when comparing children with sickle cell disease to healthy black children of a similar age, but did show a significant difference amongst our participants in contrast to their white cohorts in the aforementioned study.…”

Section: Discussionmentioning

confidence: 95%

Pupil Size and Reactivity in Pediatric Patients with Sickle Cell Disease

Mack

Frankowski

Verkamp

et al. 2020

Preprint

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Background/Objectives: Pupil size and reactivity have been studied in adult and pediatric populations to objectively measure pain which showed that pupillometry is a promising biomarker for pain measurement. Vaso-occlusive crisis, is a common complication of sickle cell disease (SCD) and better assessment tools are needed. The objective of this study is to establish normative values for pupil size and reactivity in pediatric patients with SCD with the hope that pupillometry can be used as a tool to objectively measure pain and response to treatment. Design/Methods: Institutional review board (IRB) approved prospective study enrolled 82 patients with SCD. Readings were performed using a NeurOptics PLR-2000 pupillometer. The following measures were collected: resting pupil size, % change in pupil size, pupil constriction velocity, and pupil dilation velocity. Results: Forty-four males and 38 females, all black, were studied. Median age was 11 years (range:2-21). The mean minimum and maximum pupil sizes were 3.52mm and 5.08mm, respectively. The mean dilation velocity and maximum constriction velocity were 1.03mm/s and -4.48mm/s, respectively. When comparing our participants with white participants in a previously published pediatric study, there was a significant difference in maximum constriction velocity, maximum pupil size, and minimum pupil size.1 There was no significant difference when comparing means for these parameters. Conclusion: There was no significant difference in pupil size and reactivity between patients with SCD and black patients without the disease. Further investigation of pupillometry within the black population during vaso-occlusive crisis and in the "well state" is warranted in pediatric patients with SCD.

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Establishing a normative database for quantitative pupillometry in the pediatric population

Cited by 17 publications

References 18 publications

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

Pupil Size and Reactivity in Pediatric Patients with Sickle Cell Disease

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