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Hartstein LE, LeBourgeois MK, Durniak MT, Najjar RP. Differences in the pupillary responses to evening light between children and adolescents. J Physiol Anthropol 2024; 43:16. [PMID: 38961509 PMCID: PMC11221120 DOI: 10.1186/s40101-024-00363-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 06/04/2024] [Indexed: 07/05/2024] Open
Abstract
BACKGROUND In the mammalian retina, intrinsically-photosensitive retinal ganglion cells (ipRGC) detect light and integrate signals from rods and cones to drive multiple non-visual functions including circadian entrainment and the pupillary light response (PLR). Non-visual photoreception and consequently non-visual sensitivity to light may change across child development. The PLR represents a quick and reliable method for examining non-visual responses to light in children. The purpose of this study was to assess differences in the PLRs to blue and red stimuli, measured one hour prior to bedtime, between children and adolescents. METHODS Forty healthy participants (8-9 years, n = 21; 15-16 years, n = 19) completed a PLR assessment 1 h before their habitual bedtime. After a 1 h dim-light adaptation period (< 1 lx), baseline pupil diameter was measured in darkness for 30 s, followed by a 10 s exposure to 3.0 × 1013 photons/cm2/s of either red (627 nm) or blue (459 nm) light, and a 40 s recovery in darkness to assess pupillary re-dilation. Subsequently, participants underwent 7 min of dim-light re-adaptation followed by an exposure to the other light condition. Lights were counterbalanced across participants. RESULTS Across both age groups, maximum pupil constriction was significantly greater (p < 0.001, ηp2 = 0.48) and more sustained (p < 0.001, ηp2 = 0.41) during exposure to blue compared to red light. For adolescents, the post-illumination pupillary response (PIPR), a hallmark of melanopsin function, was larger after blue compared with red light (p = 0.02, d = 0.60). This difference was not observed in children. Across light exposures, children had larger phasic (p < 0.01, ηp2 = 0.20) and maximal (p < 0.01, ηp2 = 0.22) pupil constrictions compared to adolescents. CONCLUSIONS Blue light elicited a greater and more sustained pupillary response than red light in children and adolescents. However, the overall amplitude of the rod/cone-driven phasic response was greater in children than in adolescents. Our findings using the PLR highlight a higher sensitivity to evening light in children compared to adolescents, and continued maturation of the human non-visual photoreception/system throughout development.
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Affiliation(s)
- Lauren E Hartstein
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA.
| | - Monique K LeBourgeois
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | | | - Raymond P Najjar
- Center for Innovation & Precision Eye Health, Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- ASPIRE Research Program, Singapore Eye Research Institute, Singapore, Singapore
- Duke-NUS School of Medicine, Singapore, Singapore
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore, Singapore
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2
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Finkelstein MT, Nongpiur ME, Husain R, Perera S, Baskaran M, Wong TT, Aung T, Milea D, Najjar RP. Handheld chromatic pupillometry can reliably detect functional glaucomatous damage in eyes with high myopia. Br J Ophthalmol 2024; 108:818-825. [PMID: 37524446 DOI: 10.1136/bjo-2023-323878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/12/2023] [Indexed: 08/02/2023]
Abstract
BACKGROUND/AIMS To assess pupillary light responses (PLRs) in eyes with high myopia (HM) and evaluate the ability of handheld chromatic pupillometry (HCP) to identify glaucomatous functional loss in eyes with HM. METHODS This prospective, cross-sectional study included 28 emmetropes (EM), 24 high myopes without glaucoma (HM) and 17 high myopes with confirmed glaucoma (HMG), recruited at the Singapore National Eye Center. Monocular PLRs were evaluated using a custom-built handheld pupillometer that recorded changes in horizontal pupil radius in response to 9 s of exponentially increasing blue (469.1 nm) and red (640.1 nm) lights. Fifteen pupillometric features were compared between groups. A logistic regression model (LRM) was used to distinguish HMG eyes from non-glaucomatous eyes (EM and HM). RESULTS All pupillometric features were similar between EM and HM groups. Phasic constriction to blue (p<0.001) and red (p=0.006) lights, and maximum constriction to blue light (p<0.001) were reduced in HMG compared with EM and HM. Pupillometric features of melanopsin function (postillumination pupillary response, PIPR area under the curve (AUC) 0-12 s (p<0.001) and PIPR 6 s (p=0.01) to blue light) were reduced in HMG. Using only three pupillometric features, the LRM could classify glaucomatous from non-glaucomatous eyes with an AUC of 0.89 (95% CI 0.77 to 1.00), sensitivity 94.1% (95% CI 82.4% to 100.0%) and specificity 78.8% (95% CI 67.3% to 90.4%). CONCLUSION PLRs to ramping-up light stimuli are unaltered in highly myopic eyes without other diagnosed ocular conditions. Conversely, HCP can distinguish glaucomatous functional loss in eyes with HM and can be a useful tool to detect/confirm the presence of glaucoma in patients with HM.
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Affiliation(s)
| | - Monisha Esther Nongpiur
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Rahat Husain
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Shamira Perera
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Mani Baskaran
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
| | - Tina T Wong
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Ocular Therapeutics & Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tin Aung
- Glaucoma, Singapore Eye Research Institute, Singapore
- Glaucoma, Singapore National Eye Centre, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
| | - Dan Milea
- Visual Neurosciences, Singapore Eye Research Institute, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Neuro-ophthalmology, Singapore National Eye Centre, Singapore
| | - Raymond P Najjar
- Visual Neurosciences, Singapore Eye Research Institute, Singapore
- Ophthalmology & Visual Sciences, Duke-NUS Medical School, Singapore
- Ophthalmology, National University of Singapore, Singapore
- Biomedical Engineering, National University of Singapore, Singapore
- Center for Innovation & Precision Eye Health, National University of Singapore, Singapore
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3
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Vilotijević A, Mathôt S. Functional benefits of cognitively driven pupil-size changes. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2024; 15:e1672. [PMID: 38149763 DOI: 10.1002/wcs.1672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 10/30/2023] [Accepted: 11/27/2023] [Indexed: 12/28/2023]
Abstract
Pupil-size changes are typically associated with the pupil light response (PLR), where they are driven by the physical entry of light into the eye. However, pupil-size changes are also influenced by various cognitive processes, where they are driven by higher-level cognition. For example, the strength of the PLR is not solely affected by physical properties of the light but also by cognitive factors, such as whether the source of light is attended or not, which results in an increase or decrease in the strength of the PLR. Surprisingly, although cognitively driven pupil-size changes have been the focus of extensive research, their possible functions are rarely discussed. Here we consider the relative (dis)advantages of small versus large pupils in different situations from a theoretical point of view, and compare these to empirical results showing how pupil size actually changes in these situations. Based on this, we suggest that cognitively driven pupil-size changes optimize vision either through preparation, embodied representations, or a differential emphasis on central or peripheral vision. More generally, we argue that cognitively driven pupil-size changes are a form of sensory tuning: a subtle adjustment of the eyes to optimize vision for the current situation and the immediate future. This article is categorized under: Neuroscience > Cognition Neuroscience > Physiology Neuroscience > Behavior.
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Affiliation(s)
- Ana Vilotijević
- Department of Psychology, University of Groningen, The Netherlands
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Burgess HJ, Troost JP, Rizvydeen M, Kikyo F, Kebbeh N, Tan M, Roecklein KA, King AC, Hasler BP. Do sleep and circadian characteristics predict alcohol use in adult drinkers? ALCOHOL, CLINICAL & EXPERIMENTAL RESEARCH 2024; 48:680-691. [PMID: 38546532 PMCID: PMC11015972 DOI: 10.1111/acer.15280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 01/16/2024] [Accepted: 02/02/2024] [Indexed: 04/14/2024]
Abstract
BACKGROUND While sleep and circadian rhythms are recognized contributors to the risk for alcohol use and related problems, few studies have examined whether objective sleep and circadian measures can predict future alcohol use in humans, and no such studies have been conducted in adults. This study examined whether any baseline sleep and/or circadian characteristics of otherwise healthy adults predicted their alcohol use over the subsequent 12 months. METHODS Participants (21-42 years) included 28 light and 50 heavy drinkers. At baseline, a comprehensive range of self-reported and objective sleep/circadian measures was assessed via questionnaires, wrist actigraphy, and measurement of dim light melatonin onset and circadian photoreceptor responsivity. Following this, the number of alcoholic drinks per week and binge drinking episodes per month were assessed quarterly over the subsequent 12 months. Anticipated effects of alcohol (stimulation, sedation, and rewarding aspects) were also assessed quarterly over the 12 months. Analyses included generalized linear mixed-effects models and causal mediation analysis. RESULTS Across the range of measures, only self-reported insomnia symptoms and a longer total sleep time at baseline predicted more drinks per week and binges per month (ps <0.02). There was a trend for the anticipated alcohol effect of wanting more alcohol at the 6-month timepoint to mediate the relationship between insomnia symptoms at baseline and drinks per week at 12 months (p = 0.069). CONCLUSIONS These results suggest that in otherwise healthy adults, insomnia symptoms, even if subclinical, are a significant predictor of future drinking, and appear to outweigh the influence of circadian factors on future drinking, at least in otherwise healthy adults. Insomnia symptoms may be a modifiable target for reducing the risk of alcohol misuse.
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Affiliation(s)
- Helen J. Burgess
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Jonathan P. Troost
- Michigan Institute for Clinical & Health Research, University of Michigan, Ann Arbor, MI USA
| | - Muneer Rizvydeen
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Fumitaka Kikyo
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, IL, USA
| | - Nema Kebbeh
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Michael Tan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, IL, USA
| | | | - Andrea C. King
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - Brant P. Hasler
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
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Vilotijević A, Mathôt S. Non-image-forming vision as measured through ipRGC-mediated pupil constriction is not modulated by covert visual attention. Cereb Cortex 2024; 34:bhae107. [PMID: 38521995 PMCID: PMC10960954 DOI: 10.1093/cercor/bhae107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 03/25/2024] Open
Abstract
In brightness, the pupil constricts, while in darkness, the pupil dilates; this is known as the pupillary light response (PLR). The PLR is driven by all photoreceptors: rods and cones, which contribute to image-forming vision, and intrinsically photosensitive retinal ganglion cells (ipRGCs), which mainly contribute to non-image-forming vision. Rods and cones cause immediate pupil constriction upon light exposure, whereas ipRGCs cause sustained constriction throughout light exposure. Recent studies have shown that covert attention modulated the initial PLR; however, it remains unclear whether the same holds for the sustained PLR. We tested this by leveraging ipRGCs' responsiveness to blue light, causing the most prominent sustained constriction. While replicating previous studies by showing that pupils constricted more when either directly looking at, or covertly attending to, bright as compared to dim stimuli (with the same color), we also found that the pupil constricted more when directly looking at blue as compared to red stimuli (with the same luminosity). Crucially, however, in two high-powered studies (n = 60), we did not find any pupil-size difference when covertly attending to blue as compared to red stimuli. This suggests that ipRGC-mediated pupil constriction, and possibly non-image-forming vision more generally, is not modulated by covert attention.
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Affiliation(s)
- Ana Vilotijević
- Department of Psychology, University of Groningen, Grote Kruisstraat 2/1 9712TS Groningen, The Netherlands
| | - Sebastiaan Mathôt
- Department of Psychology, University of Groningen, Grote Kruisstraat 2/1 9712TS Groningen, The Netherlands
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Romagnoli M, Amore G, Avanzini P, Carelli V, La Morgia C. Chromatic pupillometry for evaluating melanopsin retinal ganglion cell function in Alzheimer's disease and other neurodegenerative disorders: a review. Front Psychol 2024; 14:1295129. [PMID: 38259552 PMCID: PMC10801184 DOI: 10.3389/fpsyg.2023.1295129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 12/11/2023] [Indexed: 01/24/2024] Open
Abstract
The evaluation of pupillary light reflex (PLR) by chromatic pupillometry may provide a unique insight into specific photoreceptor functions. Chromatic pupillometry refers to evaluating PLR to different wavelengths and intensities of light in order to differentiate outer/inner retinal photoreceptor contributions to the PLR. Different protocols have been tested and are now established to assess in-vivo PLR contribution mediated by melanopsin retinal ganglion cells (mRGCs). These intrinsically photosensitive photoreceptors modulate the non-image-forming functions of the eye, which are mainly the circadian photoentrainment and PLR, via projections to the hypothalamic suprachiasmatic and olivary pretectal nucleus, respectively. In this context, chromatic pupillometry has been used as an alternative and non-invasive tool to evaluate the mRGC system in several clinical settings, including hereditary optic neuropathies, glaucoma, and neurodegenerative disorders such as Parkinson's disease (PD), idiopathic/isolated rapid eye movement sleep behavior disorder (iRBD), and Alzheimer's disease (AD). The purpose of this article is to review the key steps of chromatic pupillometry protocols for studying in-vivo mRGC-system functionality and provide the main findings of this technique in the research setting on neurodegeneration. mRGC-dependent pupillary responses are short-wavelength sensitive, have a higher threshold of activation, and are much slower and sustained compared with rod- and cone-mediated responses, driving the tonic component of the PLR during exposure to high-irradiance and continuous light stimulus. Thus, mRGCs contribute mainly to the tonic component of the post-illumination pupil response (PIPR) to bright blue light flash that persists after light stimulation is switched off. Given the role of mRGCs in circadian photoentrainment, the use of chromatic pupillometry to perform a functional evaluation of mRGcs may be proposed as an early biomarker of mRGC-dysfunction in neurodegenerative disorders characterized by circadian and/or sleep dysfunction such as AD, PD, and its prodromal phase iRBD. The evaluation by chromatic pupillometry of mRGC-system functionality may lay the groundwork for a new, easily accessible biomarker that can be exploited also as the starting point for future longitudinal cohort studies aimed at stratifying the risk of conversion in these disorders.
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Affiliation(s)
- Martina Romagnoli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Giulia Amore
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | | | - Valerio Carelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Chiara La Morgia
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
- IRCCS Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, Bologna, Italy
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Hartstein LE, LeBourgeois MK, Durniak MT, Najjar RP. Differences in the Pupillary Responses to Evening Light between Children and Adolescents. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.09.552691. [PMID: 37645820 PMCID: PMC10461909 DOI: 10.1101/2023.08.09.552691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Purpose To assess differences in the pupillary light responses (PLRs) to blue and red evening lights between children and adolescents. Methods Forty healthy participants (8-9 years, n=21; 15-16 years, n=19) completed a PLR assessment 1 h before their habitual bedtime. After a 1 h dim-light adaptation period (<1 lux), baseline pupil diameter was measured in darkness for 30 s, followed by a 10 s exposure to 3.0×1013 photons/cm2/s of either red (627 nm) or blue (459 nm) light, and a 40 s recovery in darkness to assess pupillary re-dilation. Subsequently, participants underwent 7 min of dim-light re-adaptation followed by an exposure to the other light condition. Lights were counterbalanced across participants. Results Across both age groups, maximum pupil constriction was significantly greater (p< 0.001, ηp2=0.48) and more sustained (p< 0.001, ηp2=0.41) during exposure to blue compared to red light. For adolescents, the post-illumination pupillary response (PIPR), a hallmark of melanopsin function, was larger after blue compared with red light (p= 0.02, d=0.60). This difference was not observed in children. Across light exposures, children had larger phasic (p< 0.01, ηp2=0.20) and maximal (p< 0.01, ηp2=0.22) pupil constrictions compared to adolescents. Conclusions Blue light elicited a greater and more sustained pupillary response than red light across participants. However, the overall amplitude of the rod/cone-driven phasic response was greater in children than in adolescents. Our findings using the PLR highlight a higher sensitivity to evening light in children compared to adolescents, and continued maturation of the human non-visual photoreception/system throughout development.
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Affiliation(s)
- Lauren E. Hartstein
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | | | | | - Raymond P. Najjar
- Center for Innovation & Precision Eye Health, Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- ASPIRE Research Program, Singapore Eye Research Institute, Singapore
- Duke-NUS School of Medicine, Singapore
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, Singapore
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Schilling T, Soltanlou M, Nuerk HC, Bahmani H. Blue-light stimulation of the blind-spot constricts the pupil and enhances contrast sensitivity. PLoS One 2023; 18:e0286503. [PMID: 37256905 DOI: 10.1371/journal.pone.0286503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 05/17/2023] [Indexed: 06/02/2023] Open
Abstract
Short- and long-wavelength light can alter pupillary responses differently, allowing inferences to be made about the contribution of different photoreceptors on pupillary constriction. In addition to classical retinal photoreceptors, the pupillary light response is formed by the activity of melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGC). It has been shown in rodents that melanopsin is expressed in the axons of ipRGCs that bundle at the optic nerve head, which forms the perceptual blind-spot. Hence, the first aim of this study was to investigate if blind-spot stimulation induces a pupillary response. The second aim was to investigate the effect of blind-spot stimulation by using the contrast sensitivity tests. Fifteen individuals participated in the pupil response experiment and thirty-two individuals in the contrast sensitivity experiment. The pupillary change was quantified using the post-illumination pupil response (PIPR) amplitudes after blue-light (experimental condition) and red-light (control condition) pulses in the time window between 2 s and 6 s post-illumination. The contrast sensitivity was assessed using two different tests: the Freiburg Visual Acuity Test and Contrast Test and the Tuebingen Contrast Sensitivity Test, respectively. Contrast sensitivity was measured before and 20 minutes after binocular blue-light stimulation of the blind-spot at spatial frequencies higher than or equal to 3 cycles per degree (cpd) and at spatial frequencies lower than 3 cpd (control condition). Blue-light blind-spot stimulation induced a significantly larger PIPR compared to red-light, confirming a melanopsin-mediated pupil-response in the blind-spot. Furthermore, contrast sensitivity was increased after blind-spot stimulation, confirmed by both contrast sensitivity tests. Only spatial frequencies of at least 3 cpd were enhanced. This study demonstrates that stimulating the blind-spot with blue-light constricts the pupil and increases the contrast sensitivity at higher spatial frequencies.
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Affiliation(s)
| | - Mojtaba Soltanlou
- Department of Psychology, University of Tuebingen, Tuebingen, Germany
- School of Psychology, University of Surrey, Guildford, United Kingdom
| | - Hans-Christoph Nuerk
- Department of Psychology, University of Tuebingen, Tuebingen, Germany
- LEAD Graduate School & Research Network, University of Tuebingen, Tuebingen, Germany
| | - Hamed Bahmani
- Dopavision GmbH, Berlin, Germany
- Bernstein Center for Computational Neuroscience, Tuebingen, Germany
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Bordt AS, Patterson SS, Kuchenbecker JA, Mazzaferri MA, Yearick JN, Yang ER, Ogilvie JM, Neitz J, Marshak DW. Synaptic inputs to displaced intrinsically-photosensitive ganglion cells in macaque retina. Sci Rep 2022; 12:15160. [PMID: 36071126 PMCID: PMC9452553 DOI: 10.1038/s41598-022-19324-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 08/26/2022] [Indexed: 11/08/2022] Open
Abstract
Ganglion cells are the projection neurons of the retina. Intrinsically photosensitive retinal ganglion cells (ipRGCs) express the photopigment melanopsin and also receive input from rods and cones via bipolar cells and amacrine cells. In primates, multiple types of ipRGCs have been identified. The ipRGCs with somas in the ganglion cell layer have been studied extensively, but less is known about those with somas in the inner nuclear layer, the "displaced" cells. To investigate their synaptic inputs, three sets of horizontal, ultrathin sections through central macaque retina were collected using serial block-face scanning electron microscopy. One displaced ipRGC received nearly all of its excitatory inputs from ON bipolar cells and would therefore be expected to have ON responses to light. In each of the three volumes, there was also at least one cell that had a large soma in the inner nuclear layer, varicose axons and dendrites with a large diameter that formed large, extremely sparse arbor in the outermost stratum of the inner plexiform layer. They were identified as the displaced M1 type of ipRGCs based on this morphology and on the high density of granules in their somas. They received extensive input from amacrine cells, including the dopaminergic type. The vast majority of their excitatory inputs were from OFF bipolar cells, including two subtypes with extensive input from the primary rod pathway. They would be expected to have OFF responses to light stimuli below the threshold for melanopsin or soon after the offset of a light stimulus.
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Affiliation(s)
- Andrea S Bordt
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, TX, USA
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - Sara S Patterson
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
- Center for Visual Science, University of Rochester, Rochester, NY, USA
| | | | | | - Joel N Yearick
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Emma R Yang
- Department of BioSciences, Rice University, Houston, TX, USA
| | | | - Jay Neitz
- Department of Ophthalmology, University of Washington, Seattle, WA, USA
| | - David W Marshak
- Department of Neurobiology and Anatomy, McGovern Medical School, Houston, TX, USA.
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Tripolone MC, Issolio LA, Agüero C, Lavaque A, Cao D, Barrionuevo PA. Comparing flickering and pulsed chromatic pupil light responses. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2022; 39:1505-1512. [PMID: 36215596 DOI: 10.1364/josaa.455619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 07/12/2022] [Indexed: 06/16/2023]
Abstract
The pupil light reflex (PLR) can serve as a biomarker of the photoreceptor function. Protocols for chromatic PLR consider mostly pulsed stimulation. A more sophisticated and promising technique is based on the PLR to flickering stimulation. Our aim was to compare flickering PLR (fPLR) and pulsed PLR (pPLR) parameters to validate the fPLR paradigm. Two different experiments were carried out in young participants to compare parameters of chromatic pupillary measurements under flickering and pulsed conditions. We found that the fPLR amplitude parameter was significantly associated with the pPLR transient constriction parameter. Also, for some conditions, pulse parameters can be identified directly in the fPLR recordings.
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Burgess HJ, Rizvydeen M, Kikyo F, Kebbeh N, Tan M, Roecklein KA, Hasler BP, King AC, Cao D. Sleep and circadian differences between light and heavy adult alcohol drinkers. Alcohol Clin Exp Res 2022; 46:1181-1191. [PMID: 35908247 PMCID: PMC9357170 DOI: 10.1111/acer.14872] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 05/03/2022] [Accepted: 05/09/2022] [Indexed: 12/01/2022]
Abstract
Background Numerous studies have reported that eveningness is associated with increased alcohol consumption. However, biological markers of circadian timing, such as dim light melatonin onset (DLMO) and circadian photoreceptor responsivity (post‐illumination pupil response, PIPR), have rarely been assessed in the context of habitual alcohol consumption. This study aimed to examine sleep, circadian timing, and photoreceptor responsivity in adult alcohol drinkers. Methods Participants (21 to 45 years) included 28 light and 50 heavy drinkers. The 8‐day study consisted of a week of adlib sleep monitored with wrist actigraphy, followed by a 9‐h laboratory session with a photoreceptor responsivity and circadian phase assessment. Results The heavy drinkers obtained on average 28 more minutes of sleep (p = 0.002) and reported more eveningness than the light drinkers (p = 0.029). There was a trend for a shorter DLMO‐midsleep interval (p = 0.059) in the heavy drinkers, reflecting a tendency for them to sleep at an earlier circadian phase. The PIPR in the heavy drinkers was significantly smaller than in the light drinkers (p = 0.032), suggesting reduced circadian photoreceptor responsivity in the heavy drinkers. A larger PIPR was significantly associated with a later DLMO in the light drinkers (r = 0.44, p = 0.019), but this relationship was absent in the heavy drinkers (r = −0.01, p = 0.94). Conclusions These results are consistent with earlier reports of more eveningness and a shorter DLMO‐midsleep interval being associated with heavier alcohol drinking. The novel finding of reduced circadian photoreceptor responsivity in heavy drinkers is consistent with prior rodent studies. Future studies should explore the impact of habitual alcohol consumption on other measures of circadian photoreceptor responsivity.
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Affiliation(s)
- Helen J Burgess
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Muneer Rizvydeen
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Fumitaka Kikyo
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Nema Kebbeh
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Michael Tan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Kathryn A Roecklein
- Department of Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brant P Hasler
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Andrea C King
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois, USA
| | - Dingcai Cao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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12
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Uprety S, Adhikari P, Feigl B, Zele AJ. Melanopsin photoreception differentially modulates rod-mediated and cone-mediated human temporal vision. iScience 2022; 25:104529. [PMID: 35754721 PMCID: PMC9218364 DOI: 10.1016/j.isci.2022.104529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/04/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
To evaluate the nature of interactions between visual pathways transmitting the slower melanopsin and faster rod and cone signals, we implement a temporal phase summation paradigm in human observers using photoreceptor-directed stimuli. We show that melanopsin stimulation interacts with and alters both rod-mediated and cone-mediated vision regardless of whether it is perceptually visible or not. Melanopsin-rod interactions result in either inhibitory or facilitatory summation depending on the temporal frequency and photoreceptor pathway contrast sensitivity. Moreover, by isolating rod vision, we reveal a bipartite intensity response property of the rod pathway in photopic lighting that extends its operational range at lower frequencies to beyond its classic saturation limits but at the expense of attenuating sensitivity at higher frequencies. In comparison, melanopsin-cone interactions always lead to facilitation. These interactions can be described by linear or probability summations and potentially involve multiple intraretinal and visual cortical pathways to set human visual contrast sensitivity. Melanopsin ipRGCs support vision independent of the rod and cone signals Rod pathways mediate robust visual responses in daylight Temporal contrast sensitivity is contingent on the melanopsin excitation level Visual performance is collectively regulated by melanopsin, rod and cone pathways
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Affiliation(s)
- Samir Uprety
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Prakash Adhikari
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
| | - Beatrix Feigl
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,Queensland Eye Institute, Brisbane, QLD 4101, Australia
| | - Andrew J Zele
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD 4059, Australia
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13
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Najjar RP, Rukmini AV, Finkelstein MT, Nusinovici S, Mani B, Nongpiur ME, Perera S, Husain R, Aung T, Milea D. Handheld chromatic pupillometry can accurately and rapidly reveal functional loss in glaucoma. Br J Ophthalmol 2021; 107:663-670. [PMID: 34853018 PMCID: PMC10176376 DOI: 10.1136/bjophthalmol-2021-319938] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 11/06/2021] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIMS Early detection and treatment of glaucoma can delay vision loss. In this study, we evaluate the performance of handheld chromatic pupillometry (HCP) for the objective and rapid detection of functional loss in glaucoma. METHODS In this clinic-based, prospective study, we enrolled 149 patients (median (IQR) years: 68.5 (13.6) years) with confirmed glaucoma and 173 healthy controls (55.2 (26.7) years). Changes in pupil size in response to 9 s of exponentially increasing blue (469 nm) and red (640 nm) light-stimuli were assessed monocularly using a custom-built handheld pupillometer. Pupillometric features were extracted from individual traces and compared between groups. Features with the highest classification potential, selected using a gradient boosting machine technique, were incorporated into a generalised linear model for glaucoma classification. Receiver operating characteristic curve analyses (ROC) were used to compare the performance of HCP, optical coherence tomography (OCT) and Humphrey Visual Field (HVF). RESULTS Pupillary light responses were altered in glaucoma compared with controls. For glaucoma classification, HCP yielded an area under the ROC curve (AUC) of 0.94 (95% CI 0.91 to 0.96), a sensitivity of 87.9% and specificity of 88.4%. The classification performance of HCP in early-moderate glaucoma (visual field mean deviation (VFMD) > -12 dB; AUC=0.91 (95% CI 0.87 to 0.95)) was similar to HVF (AUC=0.91) and reduced compared with OCT (AUC=0.97; p=0.01). For severe glaucoma (VFMD ≤ -12 dB), HCP had an excellent classification performance (AUC=0.98, 95% CI 0.97 to 1) that was similar to HVF and OCT. CONCLUSION HCP allows for an accurate, objective and rapid detection of functional loss in glaucomatous eyes of different severities.
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Affiliation(s)
- Raymond P Najjar
- Visual Neurosciences Research Group, Singapore Eye Research Institute, Singapore.,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore
| | - A V Rukmini
- Visual Neurosciences Research Group, Singapore Eye Research Institute, Singapore
| | | | - Simon Nusinovici
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Ocular Epidemiology Research Group, Singapore Eye Research Institute, Singapore
| | - Baskaran Mani
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore.,Glaucoma Research Group, Singapore Eye Research Institute, Singapore
| | - Monisha Esther Nongpiur
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore.,Glaucoma Research Group, Singapore Eye Research Institute, Singapore
| | - Shamira Perera
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore
| | - Rahat Husain
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore
| | - Tin Aung
- Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Glaucoma Department, Singapore National Eye Centre, Singapore.,Glaucoma Research Group, Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Dan Milea
- Visual Neurosciences Research Group, Singapore Eye Research Institute, Singapore .,Ophthalmology and Visual Sciences Academic Clinical Programme, Duke-NUS Medical School, Singapore.,Neuro-Ophthalmology Department, Singapore National Eye Center, Singapore
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14
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Adhikari P, Pradhan A, Zele AJ, Feigl B. Supplemental light exposure improves sleep architecture in people with type 2 diabetes. Acta Diabetol 2021; 58:1201-1208. [PMID: 33851274 DOI: 10.1007/s00592-021-01712-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 03/24/2021] [Indexed: 12/28/2022]
Abstract
AIMS People with type 2 diabetes (T2D) suffer from sleep disorders, with the mechanism not clearly understood. In T2D, the light transducing retinal photoreceptors that regulate sleep behaviours are dysfunctional; hence, we determine here whether supplemental light exposure ameliorates sleep quality and daytime sleepiness in T2D. METHODS Supplemental light (10,000 Lux, polychromatic) was self-administered for 30 min every morning for 14 days by ten participants with T2D with no diabetic retinopathy (DR). The effectiveness of supplemental light was assessed by comparing subjective sleep questionnaire (PSQI and ESS) scores and salivary dim light melatonin onset (DLMO) before and after the light exposure as well as with a self-maintained sleep diary during the light exposure. RESULTS Compared to the baseline, supplemental light significantly improved the excessive daytime sleepiness score (p = 0.004) and phase-advanced the DLMO on average by ~ 23 min. Sleep diary analyses showed that afternoon nap duration significantly shortened over the first week of supplemental light exposure (p = 0.019). Afternoon naps and midnight awakening were significantly longer in diabetic participants with thinner perifoveal retina. CONCLUSIONS In this case series, we provide initial evidence that supplemental bright light improves daytime sleepiness in T2D with no DR, with the critical period of light exposure showing a beneficial effect after one week. We infer that supplemental light augments photoreceptor signalling in T2D and therefore optimises circadian photoentrainment leading to improved sleep. Our findings inform the development of tailored light therapy protocols in future clinical trials for improving sleep architecture in diabetes.
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Affiliation(s)
- Prakash Adhikari
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
| | - Asik Pradhan
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
| | - Andrew J Zele
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia
| | - Beatrix Feigl
- Centre for Vision and Eye Research, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia.
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, 4059, Australia.
- Queensland Eye Institute, Brisbane, Australia.
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15
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Mostafa J, Porter J, Queener HM, Ostrin LA. Intrinsically photosensitive retinal ganglion cell-driven pupil responses in patients with traumatic brain injury. Vision Res 2021; 188:174-183. [PMID: 34352476 DOI: 10.1016/j.visres.2021.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 05/25/2021] [Accepted: 07/14/2021] [Indexed: 10/20/2022]
Abstract
Previous findings regarding intrinsically photosensitive retinal ganglion cell (ipRGC) function after traumatic brain injury (TBI) are conflicting. We examined ipRGC-driven pupil responses in civilian TBI and control participants using two pupillography protocols that assessed transient and adaptive properties: (1) a one second (s) long wavelength "red" stimulus (651 nm, 133 cd/m2) and 10 increasing intensities of 1 s short wavelength "blue" stimuli (456 nm, 0.167 to 167 cd/m2) with a 60 s interstimulus interval, and (2) two minutes of 0.1 Hz red stimuli (33 cd/m2), followed by two minutes of 0.1 Hz blue stimuli (16 cd/m2). For Protocol 1, constriction amplitude and the 6 s post illumination pupil response (PIPR) were calculated. For Protocol 2, amplitudes and peak velocities of pupil constriction and redilation were calculated. For Protocol 1, constriction amplitude and the 6 s PIPR were not significantly different between TBI patients and control subjects for red or blue stimuli. For Protocol 2, pupil constriction amplitude attenuated over time for red stimuli and potentiated over time for blue stimuli across all subjects. Constriction and redilation velocities were similar between groups. Pupil constriction amplitude was significantly less in TBI patients compared to control subjects for red and blue stimuli, which can be attributed to age-related differences in baseline pupil size. While TBI, in addition to age, may have contributed to decreased baseline pupil diameter and constriction amplitude, responses to blue stimulation suggest no selective damage to ipRGCs.
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Affiliation(s)
- Jakaria Mostafa
- University of Houston College of Optometry, 4901 Calhoun Rd, Houston, TX 77004, United States
| | - Jason Porter
- University of Houston College of Optometry, 4901 Calhoun Rd, Houston, TX 77004, United States
| | - Hope M Queener
- University of Houston College of Optometry, 4901 Calhoun Rd, Houston, TX 77004, United States
| | - Lisa A Ostrin
- University of Houston College of Optometry, 4901 Calhoun Rd, Houston, TX 77004, United States.
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16
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Ali EN, Carle CF, Lueck CJ, Kolic M, Maddess T. Assessing migraine patients with multifocal pupillographic objective perimetry. BMC Neurol 2021; 21:211. [PMID: 34039302 PMCID: PMC8152334 DOI: 10.1186/s12883-021-02239-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 05/14/2021] [Indexed: 12/22/2022] Open
Abstract
Background To establish the effects of stimulating intrinsically-photosensitive retinal ganglion cells (ipRGCs) on migraine severity, and to determine if migraine produces objectively-measured visual field defects. Methods A randomized, open labelled, crossover study tested migraineurs and normal controls using multifocal pupillographic objective perimetry (mfPOP) with 44 test-regions/eye. A slow blue protocol (BP) stimulated ipRGCs, and a fast yellow protocol (YP) stimulated luminance channels. Migraine diaries assessed migraine severity. Per-region responses were analyzed according to response amplitude and time-to-peak. Results Thirty-eight migraineurs (42.0 ± 16.5 years, 23 females) and 24 normal controls (39.2 ± 15.2 years, 14 females) were tested. The proportion of subjects developing a migraine did not differ after either protocol, either during the 1st day (odds ratio 1.0; 95% confidence interval 0.2–4.4, p = 0.48) or during the first 3 days after testing (odds ratio 0.8; 95% confidence interval 0.3–2.1, p = 0.68). Migraine days/week did not increase following testing with either protocol in comparison to the baseline week (1.4 ± 1.6 pre-testing (mean ± SD), 1.3 ± 1.4 post-BP, and 1.3 ± 1.2 post-YP; p = 0.96), neither did other measures of severity. Migraine occurring up to 2 weeks before testing significantly lowered amplitudes, − 0.64 ± 0.14 dB (mean ± SE), while triptan use increased amplitudes by 0.45 ± 0.10 dB, both at p < 0.001. Conclusions Stimulating ipRGCs did not affect migraine occurrence or severity. Pupillary response characteristics were influenced by the occurrence of a recent migraine attack and a history of triptan use.
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Affiliation(s)
- Eman N Ali
- Eccles Institute of Neuroscience, the John Curtin School of Medical Research, Australian National University, Acton, ACT, Australia.,Department of Neuroscience, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Corinne F Carle
- Eccles Institute of Neuroscience, the John Curtin School of Medical Research, Australian National University, Acton, ACT, Australia
| | - Christian J Lueck
- Australian National University Medical School, Acton, ACT, Australia.,Department of Neurology, The Canberra Hospital, Canberra, ACT, Australia
| | - Maria Kolic
- Eccles Institute of Neuroscience, the John Curtin School of Medical Research, Australian National University, Acton, ACT, Australia
| | - Ted Maddess
- Eccles Institute of Neuroscience, the John Curtin School of Medical Research, Australian National University, Acton, ACT, Australia.
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17
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Quantification of the early pupillary dilation kinetic to assess rod and cone activity. Sci Rep 2021; 11:9549. [PMID: 33953266 PMCID: PMC8099900 DOI: 10.1038/s41598-021-88915-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 04/12/2021] [Indexed: 12/01/2022] Open
Abstract
Rods, cones and melanopsin contribute in various proportions, depending on the stimulus light, to the pupil light response. This study used a first derivative analysis to focus on the quantification of the dynamics of pupillary dilation that immediately follows light-induced pupilloconstriction in order to identify novel parameters that reflect rod and cone activity. In 18 healthy adults, the pupil response to a 1 s blue light stimulus ranging from − 6.0 to 2.65 log cd/m2 in dark-adapted conditions and to a 1 s blue light stimulus (2.65 log cd/m2) in light-adapted conditions was recorded on a customized pupillometer. Three derivative parameters which describe the 2.75 s following the light onset were quantified: dAMP (maximal amplitude of the positive peak), dLAT (latency of the positive peak), dAUC (area under the curve of the positive peak). We found that dAMP and dAUC but not dLAT have graded responses over a range of light intensities. The maximal positive value of dAMP, representing maximal rate of change of early pupillary dilation phase, occurs at − 1.0 log cd/m2 and this stimulus intensity appears useful for activating rods and cones. From − 0.5 log cd/m2 to brighter intensities dAMP and dAUC progressively decrease, reaching negligible values at 2.65 log cd/m2 indicative of a melanopsin-driven pupil response that masks the contribution from rods and cones to the early phase of pupillary dilation.
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18
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Tabashum T, Zaffer A, Yousefzai R, Colletta K, Jost MB, Park Y, Chawla J, Gaynes B, Albert MV, Xiao T. Detection of Parkinson's Disease Through Automated Pupil Tracking of the Post-illumination Pupillary Response. Front Med (Lausanne) 2021; 8:645293. [PMID: 33842509 PMCID: PMC8026862 DOI: 10.3389/fmed.2021.645293] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/01/2021] [Indexed: 12/12/2022] Open
Abstract
Parkinson's disease (PD) is one of the most common neurodegenerative disorders, but it is often diagnosed after the majority of dopaminergic cells are already damaged. It is critical to develop biomarkers to identify the disease as early as possible for early intervention. PD patients appear to have an altered pupillary response consistent with an abnormality in photoreceptive retinal ganglion cells. Tracking the pupil size manually is a tedious process and offline automated systems can be prone to errors that may require intervention; for this reason in this work we describe a system for pupil size estimation with a user interface to allow rapid adjustment of parameters and extraction of pupil parameters of interest for the present study. We implemented a user-friendly system designed for clinicians to automate the process of tracking the pupil diameter to measure the post-illumination pupillary response (PIPR), permit manual corrections when needed, and continue automation after correction. Tracking was automated using a Kalman filter estimating the pupil center and diameter over time. The resulting system was tested on a PD classification task in which PD subjects are known to have similar responses for two wavelengths of light. The pupillary response is measured in the contralateral eye to two different light stimuli (470 and 610 nm) for 19 PD and 10 control subjects. The measured Net PIPR indicating different responsiveness to the wavelengths was 0.13 mm for PD subjects and 0.61 mm for control subjects, demonstrating a highly significant difference (p < 0.001). Net PIPR has the potential to be a biomarker for PD, suggesting further study to determine clinical validity.
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Affiliation(s)
- Thasina Tabashum
- Department of Computer Science and Engineering, University of North Texas, Denton, TX, United States
| | - Adnaan Zaffer
- Edward Hines Jr. VA Medical Center, Hines, IL, United States
| | - Raman Yousefzai
- Edward Hines Jr. VA Medical Center, Hines, IL, United States
| | - Kalea Colletta
- Edward Hines Jr. VA Medical Center, Hines, IL, United States
| | - Mary Beth Jost
- Edward Hines Jr. VA Medical Center, Hines, IL, United States
| | - Youngsook Park
- Edward Hines Jr. VA Medical Center, Hines, IL, United States
| | | | - Bruce Gaynes
- Edward Hines Jr. VA Medical Center, Hines, IL, United States.,Department of Ophthalmology, Loyola University Chicago Stritch School of Medicine, Maywood, IL, United States
| | - Mark V Albert
- Department of Computer Science and Engineering, University of North Texas, Denton, TX, United States.,Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Ting Xiao
- Department of Computer Science and Engineering, University of North Texas, Denton, TX, United States
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19
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Abstract
SIGNIFICANCE Pupillometry protocols evaluating rod/cone- and melanopsin-driven responses often use mydriatics to ensure maximal stimulus exposure; however, retinal effects of mydriatics are not fully understood. We demonstrate that dilation with either atropine or phenylephrine results in similar enhancements of rod/cone- and melanopsin-driven pupil responses. PURPOSE The purposes of this study were to compare the effects of atropine, a muscarinic antagonist, and phenylephrine, an adrenergic agonist, on consensual pupil responses and to assess the repeatability of pupil metrics without mydriasis. METHODS Right eye pupil responses of 20 adults aged 21 to 42 years were recorded before and 45 minutes after instillation of 0.5% atropine or 2.5% phenylephrine in the left eye. Stimuli were presented to the left eye and included six alternating 1-second 651-nm "red" and 456-nm "blue" flashes. Metrics included baseline pupil diameter, maximal constriction, 6- and 30-second post-illumination pupil responses, and early (0 to 10 seconds) and late (10 to 30 seconds) areas under the curve. RESULTS Dilation of the stimulated eye with either mydriatic significantly increased the 6-second post-illumination pupil response and early and late areas under the curve for blue stimuli, and early area under the curve for red stimuli (P < .05 for all). Melanopsin-driven post-illumination pupil responses, achieved with either phenylephrine or atropine, did not significantly differ from each other (P > .05 for all). Without mydriasis, intersession intraclass correlation coefficients for pupil metrics were 0.63 and 0.50 (6- and 30-second post-illumination pupil responses, respectively) and 0.78 and 0.44 (early and late areas under the curve, respectively) for blue stimuli, with no significant difference between sessions (P > .05 for all). CONCLUSIONS Dilation with phenylephrine or atropine resulted in similar enhancements of the rod/cone- and melanopsin-driven pupil responses, despite differing mechanisms. Early pupil metrics without mydriasis demonstrated moderate to good intersession repeatability.
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20
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Electrochromic selective filtering of chronodisruptive visible wavelengths. PLoS One 2020; 15:e0241900. [PMID: 33152042 PMCID: PMC7643985 DOI: 10.1371/journal.pone.0241900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 10/22/2020] [Indexed: 01/20/2023] Open
Abstract
We present evidence of pupil response modification, as well as differential theoretical melatonin suppression through selective and dynamic electrochromic filtering of visible light in the 400-500 nm range to minimize chronodisruptive nocturnal blue light exposure. A lower activation of intrinsically photosensitive retinal ganglion cells (ipRGCs), the first step for light to reach a human's internal clock, is related to melatonin secretion therefore avoiding detrimental effects of excessive blue light exposure. Pupillary Light Reflex and Color Naming were experimentally assessed under light filtered by two different coloration states (transmissive and absorptive) of these novel dynamic filters, plus an uncoated test device, in 16 volunteers. Also, different commercial light sources at illuminances ranging from 1 to 1000 lux were differentially filtered and compared in terms of theoretical melatonin suppression. Representative parameters of the pupil responses reflected lower pupil constriction when the electrochromic filters (ECFs) were switched on (absorptive state, blue light is absorbed by the filter) compared to uncoated filters (control sample), but failed to do so under transmissive state (blue light passes through the filter) indicating less activation of ipRGCs under absorptive state (although no significant differences between states was found). Out of eight colors tested, just one showed significant differences in naming between both filter states. Thus, the ECF would have some protecting effect on ipRGC activation with very limited changes in color perception. While there are some limitations of the theoretical model used, the absorptive state yielded significantly lower theoretical melatonin suppression in all those light sources containing blue wavelengths across the illuminance range tested. This would open the way for further research on biological applications of electrochromic devices.
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21
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Ba-Ali S, Brøndsted AE, Andersen HU, Jennum P, Lund-Andersen H. Pupillary light responses in type 1 and type 2 diabetics with and without retinopathy. Acta Ophthalmol 2020; 98:477-484. [PMID: 31943805 DOI: 10.1111/aos.14348] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/20/2019] [Indexed: 01/14/2023]
Abstract
OBJECTIVE We assessed the function of rod/cones and melanopsin in type 1 (T1DM) and type 2 diabetes mellitus (T2DM) with and without non-proliferative diabetic retinopathy (NPDR). METHODS We performed pupillometry on 22 healthy controls and four diabetic groups: 12 T1DM patients without NPDR and 12 with moderate NPDR, and 16 T2DM patients without NPDR and 12 with moderate NPDR. Monocular stimulations of 20 seconds with red (λ = 633 nm) and blue light (λ = 463 nm) at ~15 log quanta/cm2 /second were performed. The primary outcome was the melanopsin-mediated late redilation phase of postillumination pupillary light response (PIPRL ate ) to blue light. The secondary outcomes were the mixed rod/cone and melanopsin responses, that is maximal pupil constriction and the early redilation phase of PIPR (PIPRE arly ). RESULTS Late redilation phase of PIPR (PIPRL ate ) to blue and red light stimuli was not significantly different between healthy control and the four diabetic groups (n.s.). The maximal pupil contractions to blue light stimulus were significantly reduced in T1DM patients as well as in T2DM patients with NPDR (p ≤ 0.02), whereas for red light stimuli, the maximal pupil constriction was only reduced in T2DM with NPDR (p < 0.01). Early redilation phase of PIPR (PIPRE arly ) to blue and red light stimuli was not significantly different between healthy controls and diabetic patients (n.s.). CONCLUSION Neither the PIPRE arly nor the PIPRL ate was significantly reduced in diabetics with or without NPDR compared to healthy controls. The reduced maximal pupil constrictions in diabetics with NPDR indicate decreased mixed rod/cone and melanopsin responses.
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Affiliation(s)
- Shakoor Ba-Ali
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Poul Jennum
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Danish Centre for Sleep Medicine, Neurophysiology Clinic, Rigshospitalet, Glostrup, Denmark
| | - Henrik Lund-Andersen
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Steno Diabetes Centre, Gentofte, Denmark
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22
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Sondereker KB, Stabio ME, Renna JM. Crosstalk: The diversity of melanopsin ganglion cell types has begun to challenge the canonical divide between image-forming and non-image-forming vision. J Comp Neurol 2020; 528:2044-2067. [PMID: 32003463 DOI: 10.1002/cne.24873] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 01/22/2020] [Accepted: 01/22/2020] [Indexed: 12/15/2022]
Abstract
Melanopsin ganglion cells have defied convention since their discovery almost 20 years ago. In the years following, many types of these intrinsically photosensitive retinal ganglion cells (ipRGCs) have emerged. In the mouse retina, there are currently six known types (M1-M6) of melanopsin ganglion cells, each with unique morphology, mosaics, connections, physiology, projections, and functions. While melanopsin-expressing cells are usually associated with behaviors like circadian photoentrainment and the pupillary light reflex, the characterization of multiple types has demonstrated a reach that may extend far beyond non-image-forming vision. In fact, studies have shown that individual types of melanopsin ganglion cells have the potential to impact image-forming functions like contrast sensitivity and color opponency. Thus, the goal of this review is to summarize the morphological and functional aspects of the six known types of melanopsin ganglion cells in the mouse retina and to highlight their respective roles in non-image-forming and image-forming vision. Although many melanopsin ganglion cell types do project to image-forming brain targets, it is important to note that this is only the first step in determining their influence on image-forming vision. Even so, the visual system has canonically been divided into these two functional realms and melanopsin ganglion cells have begun to challenge the boundary between them, providing an overlap of visual information that is complementary rather than redundant. Further studies on these ganglion cell photoreceptors will no doubt continue to illustrate an ever-expanding role for melanopsin ganglion cells in image-forming vision.
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Affiliation(s)
| | - Maureen E Stabio
- Department of Cell & Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
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23
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Ahmadi H, Lund‐Andersen H, Kolko M, Bach‐Holm D, Alberti M, Ba‐Ali S. Melanopsin-mediated pupillary light reflex and sleep quality in patients with normal tension glaucoma. Acta Ophthalmol 2020; 98:65-73. [PMID: 31062491 DOI: 10.1111/aos.14133] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 04/10/2019] [Indexed: 12/16/2022]
Abstract
PURPOSE The intrinsically photosensitive retinal ganglion cells (ipRGCs) and sleep quality are impaired in patients with primary open-angle glaucoma (POAG). In this study, we investigated whether ipRGCs and sleep quality were also impaired in patients with normal tension glaucoma (NTG). METHODS We performed pupillometry and sleep quality assessment in 15 patients with NTG and 17 healthy age-matched controls. Pupillometry protocol consisted of monocular stimulation with high illuminance (100 lux) red (633 nm, 300 cd/m2 or 15.23 log quanta/cm2 /s) and blue light (463 nm, 332 cd/m2 or 15.27 log quanta/cm2 /s) and binocular pupil measurements. Prior to light stimulation, patients were dark-adapted for 5 min. The late postillumination pupillary response (PIPRL ate ) to blue light was used as marker of ipRGC activity. Sleep quality was assessed by Pittsburgh Sleep Quality Index (PSQI) questionnaire. RESULTS The PIPRL ate to blue light was significantly reduced in patients with NTG compared to healthy subjects (p < 0.001), indicating impairment of the melanopsin-mediated pupillary pathway. There was no significant difference in the response elicited by red light (p = 0.6). Baseline pupil diameter and pupillary constriction amplitude to both red and blue light were reduced in patients with NTG (p < 0.05). The global score in PSQI was not significantly different between healthy controls and patients with NTG, indicating normal sleep quality (p = 0.6). Furthermore, we found no correlation between sleep parameters and pupillary light reflex parameters. CONCLUSION Patients with NTG exhibited reduced ipRGC activity compared to healthy subjects, while no differences were observed in sleep quality.
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Affiliation(s)
- Hamid Ahmadi
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Henrik Lund‐Andersen
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Miriam Kolko
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Daniella Bach‐Holm
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Mark Alberti
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
| | - Shakoor Ba‐Ali
- Department of Ophthalmology Rigshospitalet Glostrup Denmark
- Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
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Dumpala S, Zele AJ, Feigl B. Outer Retinal Structure and Function Deficits Contribute to Circadian Disruption in Patients With Type 2 Diabetes. Invest Ophthalmol Vis Sci 2019; 60:1870-1878. [PMID: 31042793 DOI: 10.1167/iovs.18-26297] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Light transmitted by retinal photoreceptors provides the input for circadian photoentrainment. In diabetes, there is a high prevalence of circadian and sleep disruption but the underlying causes are not well understood. Patients with diabetes can exhibit dysfunctional photoreceptors but their role in circadian health is not known. Here we quantify photoreceptor function and contributions to circadian health and sleep in patients with diabetes without diabetic retinopathy and healthy controls. Methods Rod, cone, and melanopsin function was derived using chromatic pupillometry in 47 participants including 23 patients with type 2 diabetes and 24 age-matched healthy controls after an ophthalmic examination including retinal thickness assessment using optical coherence tomography. Circadian health was determined using dim light melatonin onset (DLMO) and sleep questionnaires; light exposure was measured using actigraphy. Results Compared with the control group, the patients with diabetes had a significantly earlier DLMO (1 hour) (P = 0.008), higher subjective sleep scores (P < 0.05), a reduction in pupil constriction amplitude for red stimuli (P = 0.039) and for the early postillumination pupil response (PIPR) for blue (P = 0.024) stimuli. There were no between-group differences in the light exposure pattern, activity levels, and intrinsic melanopsin-mediated PIPR amplitude (P > 0.05). A significant correlation was evident between outer retinal thickness and DLMO (r = -0.65, P = 0.03) and the pupil constriction amplitude (r = 0.63, P = 0.03); patients with thinner retina had earlier DLMO and lower pupil amplitudes. Conclusions We infer that the observed changes in circadian function in patients with no diabetic retinopathy are due to structural and functional outer retinal rod photoreceptor deficits at early stage of diabetic eye disease.
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Affiliation(s)
- Sunila Dumpala
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Optometry and Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - Andrew J Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Optometry and Vision Sciences, Queensland University of Technology, Brisbane, Australia
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Australia.,Queensland Eye Institute, Brisbane, Australia
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25
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Adhikari P, Feigl B, Zele AJ. The flicker Pupil Light Response (fPLR). Transl Vis Sci Technol 2019; 8:29. [PMID: 31637109 PMCID: PMC6798322 DOI: 10.1167/tvst.8.5.29] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 08/07/2019] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The photoreceptor classes driving the flicker pupil light response (fPLR) to monochromatic sinusoidal temporal modulation are largely unknown. Here, we determine the photoreceptor inputs to the fPLR. METHODS The 0.5-Hz fPLR was measured in healthy observers using a Maxwellian view (41° diameter) pupillometer at five narrowband wavelengths (short: 409 nm; intermediate: 462, 507, 530 nm; and long: 592 nm) over ∼10 log units of irradiance spanning scotopic to photopic levels (5.6 to 15.6 log quanta·cm-2·s-1; -6.9 to 3.6 log cd·m-2). The relative photoreceptor contributions to the fPLR were then derived from these amplitude-irradiance functions using a criterion fPLR. RESULTS The fPLR amplitude is small (≤ 3.9 ± 3.1%; mean ± SEM) below 8.0 log quanta·cm-2·s-1 then increases with retinal irradiance in accordance with a Hill function that asymptotes between 13.0 to 15.0 log quanta·cm-2·s-1 (wavelength dependent). The Hill slope is steepest for the intermediate wavelengths. Further increases in irradiance (>15.0 log quanta·cm-2·s-1) produce a distinct suppression of the fPLR for the intermediate wavelengths. The fPLR phase delay shows a linear decrease with increasing irradiance. The spectral sensitivity of the fPLR is dominated by inner retinal melanopsin ganglion cell and outer retinal rod photoreceptor inputs to the afferent pupil control pathway; the relative melanopsin : rhodopsin weighting decreases with the transition from photopic to scotopic lighting. CONCLUSIONS The fPLR can be used as a marker of melanopsin and rod interactions during the flicker stimulation and to quantify their contributions to the post-illumination pupil response (PIPR). TRANSLATIONAL RELEVANCE These irradiance and wavelength responses will be useful in standardizing the measurements of the fPLR using chromatic pupillometry.
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Affiliation(s)
- Prakash Adhikari
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
- Queensland Eye Institute, Brisbane, Australia
| | - Andrew J. Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia
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26
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Zele AJ, Adhikari P, Cao D, Feigl B. Melanopsin driven enhancement of cone-mediated visual processing. Vision Res 2019; 160:72-81. [DOI: 10.1016/j.visres.2019.04.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/16/2019] [Accepted: 04/21/2019] [Indexed: 12/13/2022]
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Zele AJ, Adhikari P, Cao D, Feigl B. Melanopsin and Cone Photoreceptor Inputs to the Afferent Pupil Light Response. Front Neurol 2019; 10:529. [PMID: 31191431 PMCID: PMC6540681 DOI: 10.3389/fneur.2019.00529] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/03/2019] [Indexed: 11/20/2022] Open
Abstract
Background: Retinal photoreceptors provide the main stage in the mammalian eye for regulating the retinal illumination through changes in pupil diameter, with a small population of melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) forming the primary afferent pathway for this response. The purpose of this study is to determine how melanopsin interacts with the three cone photoreceptor classes in the human eye to modulate the light-adapted pupil response. Methods: We investigated the independent and combined contributions of the inner and outer retinal photoreceptor inputs to the afferent pupil pathway in participants with trichromatic color vision using a method to independently control the excitations of ipRGCs, cones and rods in the retina. Results: We show that melanopsin-directed stimuli cause a transient pupil constriction generated by cones in the shadow of retinal blood vessels; desensitizing these penumbral cone signals uncovers a signature melanopsin pupil response that includes a longer latency (292 ms) and slower time (4.1x) and velocity (7.7x) to constriction than for cone-directed stimuli, and which remains sustained post-stimulus offset. Compared to melanopsin-mediated pupil responses, the cone photoreceptor-initiated pupil responses are more transient with faster constriction latencies, higher velocities and a secondary constriction at light offset. The combined pupil responses reveal that melanopsin signals are additive with the cone signals. Conclusions: The visual system uses the L–, M–, and S–cone photoreceptor inputs to the afferent pupil pathway to accomplish the tonic modulations of pupil size to changes in image contrast. The inner retinal melanopsin-expressing ipRGCs mediate the longer-term, sustained pupil constriction to set the light-adapted pupil diameter during extended light exposures.
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Affiliation(s)
- Andrew J Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Prakash Adhikari
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, QLD, Australia
| | - Dingcai Cao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, QLD, Australia.,Queensland Eye Institute, Brisbane, QLD, Australia
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28
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Kelbsch C, Strasser T, Chen Y, Feigl B, Gamlin PD, Kardon R, Peters T, Roecklein KA, Steinhauer SR, Szabadi E, Zele AJ, Wilhelm H, Wilhelm BJ. Standards in Pupillography. Front Neurol 2019; 10:129. [PMID: 30853933 PMCID: PMC6395400 DOI: 10.3389/fneur.2019.00129] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 01/31/2019] [Indexed: 12/31/2022] Open
Abstract
The number of research groups studying the pupil is increasing, as is the number of publications. Consequently, new standards in pupillography are needed to formalize the methodology including recording conditions, stimulus characteristics, as well as suitable parameters of evaluation. Since the description of intrinsically photosensitive retinal ganglion cells (ipRGCs) there has been an increased interest and broader application of pupillography in ophthalmology as well as other fields including psychology and chronobiology. Color pupillography plays an important role not only in research but also in clinical observational and therapy studies like gene therapy of hereditary retinal degenerations and psychopathology. Stimuli can vary in size, brightness, duration, and wavelength. Stimulus paradigms determine whether rhodopsin-driven rod responses, opsin-driven cone responses, or melanopsin-driven ipRGC responses are primarily elicited. Background illumination, adaptation state, and instruction for the participants will furthermore influence the results. This standard recommends a minimum set of variables to be used for pupillography and specified in the publication methodologies. Initiated at the 32nd International Pupil Colloquium 2017 in Morges, Switzerland, the aim of this manuscript is to outline standards in pupillography based on current knowledge and experience of pupil experts in order to achieve greater comparability of pupillographic studies. Such standards will particularly facilitate the proper application of pupillography by researchers new to the field. First we describe general standards, followed by specific suggestions concerning the demands of different targets of pupil research: the afferent and efferent reflex arc, pharmacology, psychology, sleepiness-related research and animal studies.
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Affiliation(s)
- Carina Kelbsch
- Pupil Research Group, Centre for Ophthalmology, University Hospitals Tübingen, Tübingen, Germany
| | - Torsten Strasser
- Pupil Research Group, Centre for Ophthalmology, University Hospitals Tübingen, Tübingen, Germany
| | - Yanjun Chen
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, AL, United States
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Queensland Eye Institute, Brisbane, QLD, Australia
| | - Paul D. Gamlin
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Randy Kardon
- Neuro-Ophthalmology Division, University of Iowa and Iowa City VA Healthcare System, Iowa City, LA, United States
| | - Tobias Peters
- Pupil Research Group, Centre for Ophthalmology, University Hospitals Tübingen, Tübingen, Germany
| | - Kathryn A. Roecklein
- Department of Psychology, University of Pittsburgh, Pittsburgh, PA, United States
| | - Stuart R. Steinhauer
- VA Pittsburgh Healthcare System, VISN 4 MIRECC, University Drive C, Pittsburgh, PA, United States
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Elemer Szabadi
- Developmental Psychiatry, University of Nottingham, Nottingham, United Kingdom
| | - Andrew J. Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
- School of Optometry and Vision Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Helmut Wilhelm
- Pupil Research Group, Centre for Ophthalmology, University Hospitals Tübingen, Tübingen, Germany
| | - Barbara J. Wilhelm
- Pupil Research Group, Centre for Ophthalmology, University Hospitals Tübingen, Tübingen, Germany
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Kircher N, Crippa SV, Martin C, Kawasaki A, Kostic C. Maturation of the Pupil Light Reflex Occurs Until Adulthood in Mice. Front Neurol 2019; 10:56. [PMID: 30778330 PMCID: PMC6369172 DOI: 10.3389/fneur.2019.00056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 01/16/2019] [Indexed: 11/13/2022] Open
Abstract
With respect to photoreceptor function, it is well known that electroretinogram (ERG) amplitudes decrease with age, but to our knowledge, studies describing age-related changes in the pupil light response (PLR) of mice are lacking. This study recorded the PLR and ERG in C57BL/6 and Sv129S6 wild-type mice at three different ages during early adulthood. Dark- and light-adapted PLR and ERG measurements were performed at 1, 2, and 4 months of age. For PLR measurements, we used either a red (622 nm) or blue (463 nm) light stimulus (500 ms) to stimulate one eye. We selected various light intensities ranging across almost 4 log units and subsequently classified them as low, medium, or high intensity. From the recorded PLR, we selected parameters to quantify the early and late phases of the response such as the baseline pupil size, the maximal constriction amplitude, the maximal velocity, the early partial dilation (area under the curve of the positive peak of the first derivative of PLR tracing), and the sustained constriction amplitude. For ERG measurements, both scotopic and photopic responses were recorded following stimulation with green light (520 nm) at preselected intensities. The amplitudes and latencies of the a-wave and the b-wave were also analyzed. In both strains, 1-month-old animals presented with a smaller baseline pupil diameter compared to that in 2- and 4-month-old mice. They also exhibited greater maximal constriction amplitude in response to red stimuli of medium intensity. Further, 1-month-old Sv129S6 mice responded with greater constriction amplitude to all other red and blue stimuli. One-month-old C57BL/6 mice also demonstrated faster early partial dilation and smaller sustained response to low blue stimuli. The ERG of 1-month-old C57BL/6 mice showed a greater scotopic a-wave amplitude compared to that of 2-month-old mice, whereas no significant differences were found in Sv129S6 mice. These results suggest that the functional maturation of the neuronal pathway that mediates the PLR continues after 1 month of age. In studies that measure PLR to determine retinal integrity in adult mice, it is thus important to determine normative values in animals of 2 months of age.
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Affiliation(s)
- Noémie Kircher
- Group for Retinal Disorder Research, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland
| | - Sylvain V Crippa
- Group for Retinal Disorder Research, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland.,Neuro-Ophtalmology, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland
| | - Catherine Martin
- Group for Retinal Disorder Research, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland
| | - Aki Kawasaki
- Neuro-Ophtalmology, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland
| | - Corinne Kostic
- Group for Retinal Disorder Research, Department of Ophthalmology, Hôpital Ophtalmique Jules Gonin, University of Lausanne, Lausanne, Switzerland
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30
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Bonmati-Carrion MA, Hild K, Isherwood CM, Sweeney SJ, Revell VL, Madrid JA, Rol MA, Skene DJ. Effect of Single and Combined Monochromatic Light on the Human Pupillary Light Response. Front Neurol 2018; 9:1019. [PMID: 30555403 PMCID: PMC6282540 DOI: 10.3389/fneur.2018.01019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/12/2018] [Indexed: 12/16/2022] Open
Abstract
The pupillary light reflex (PLR) is a neurological reflex driven by rods, cones, and melanopsin-containing retinal ganglion cells. Our aim was to achieve a more precise picture of the effects of 5-min duration monochromatic light stimuli, alone or in combination, on the human PLR, to determine its spectral sensitivity and to assess the importance of photon flux. Using pupillometry, the PLR was assessed in 13 participants (6 women) aged 27.2 ± 5.41 years (mean ± SD) during 5-min light stimuli of purple (437 nm), blue (479 nm), red (627 nm), and combinations of red+purple or red+blue light. In addition, nine 5-min, photon-matched light stimuli, ranging in 10 nm increments peaking between 420 and 500 nm were tested in 15 participants (8 women) aged 25.7 ± 8.90 years. Maximum pupil constriction, time to achieve this, constriction velocity, area under the curve (AUC) at short (0-60 s), and longer duration (240-300 s) light exposures, and 6-s post-illumination pupillary response (6-s PIPR) were assessed. Photoreceptor activation was estimated by mathematical modeling. The velocity of constriction was significantly faster with blue monochromatic light than with red or purple light. Within the blue light spectrum (between 420 and 500 nm), the velocity of constriction was significantly faster with the 480 nm light stimulus, while the slowest pupil constriction was observed with 430 nm light. Maximum pupil constriction was achieved with 470 nm light, and the greatest AUC0-60 and AUC240-300 was observed with 490 and 460 nm light, respectively. The 6-s PIPR was maximum after 490 nm light stimulus. Both the transient (AUC0-60) and sustained (AUC240-300) response was significantly correlated with melanopic activation. Higher photon fluxes for both purple and blue light produced greater amplitude sustained pupillary constriction. The findings confirm human PLR dependence on wavelength, monochromatic or bichromatic light and photon flux under 5-min duration light stimuli. Since the most rapid and high amplitude PLR occurred within the 460-490 nm light range (alone or combined), our results suggest that color discrimination should be studied under total or partial substitution of this blue light range (460-490 nm) by shorter wavelengths (~440 nm). Thus for nocturnal lighting, replacement of blue light with purple light might be a plausible solution to preserve color discrimination while minimizing melanopic activation.
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Affiliation(s)
- Maria A Bonmati-Carrion
- Chronobiology Laboratory, Department of Physiology, IMIB-Arrixaca, University of Murcia, Murcia, Spain.,Ciber Fragilidad y Envejecimiento Saludable, Madrid, Spain
| | - Konstanze Hild
- Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, United Kingdom
| | - Cheryl M Isherwood
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Stephen J Sweeney
- Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, United Kingdom
| | - Victoria L Revell
- Surrey Clinical Research Centre, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Juan A Madrid
- Chronobiology Laboratory, Department of Physiology, IMIB-Arrixaca, University of Murcia, Murcia, Spain.,Ciber Fragilidad y Envejecimiento Saludable, Madrid, Spain
| | - Maria A Rol
- Chronobiology Laboratory, Department of Physiology, IMIB-Arrixaca, University of Murcia, Murcia, Spain.,Ciber Fragilidad y Envejecimiento Saludable, Madrid, Spain
| | - Debra J Skene
- Chronobiology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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McAdams H, Igdalova A, Spitschan M, Brainard DH, Aguirre GK. Pulses of Melanopsin-Directed Contrast Produce Highly Reproducible Pupil Responses That Are Insensitive to a Change in Background Radiance. Invest Ophthalmol Vis Sci 2018; 59:5615-5626. [PMID: 30481278 PMCID: PMC6262648 DOI: 10.1167/iovs.18-25219] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/04/2018] [Indexed: 12/22/2022] Open
Abstract
Purpose To measure the pupil response to pulses of melanopsin-directed contrast, and compare this response to those evoked by cone-directed contrast and spectrally narrowband stimuli. Methods Three-second unipolar pulses were used to elicit pupil responses in human subjects across three sessions. Thirty subjects were studied in session 1, and most returned for sessions 2 and 3. The stimuli of primary interest were "silent substitution" cone- and melanopsin-directed modulations. Red and blue narrowband pulses delivered using the post-illumination pupil response (PIPR) paradigm were also studied. Sessions 1 and 2 were identical, whereas session 3 involved modulations around higher radiance backgrounds. The pupil responses were fit by a model whose parameters described response amplitude and temporal shape. Results Group average pupil responses for all stimuli overlapped extensively across sessions 1 and 2, indicating high reproducibility. Model fits indicate that the response to melanopsin-directed contrast is prolonged relative to that elicited by cone-directed contrast. The group average cone- and melanopsin-directed pupil responses from session 3 were highly similar to those from sessions 1 and 2, suggesting that these responses are insensitive to background radiance over the range studied. The increase in radiance enhanced persistent pupil constriction to blue light. Conclusions The group average pupil response to stimuli designed through silent substitution provides a reliable probe of the function of a melanopsin-mediated system in humans. As disruption of the melanopsin system may relate to clinical pathology, the reproducibility of response suggests that silent substitution pupillometry can test if melanopsin signals differ between clinical groups.
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Affiliation(s)
- Harrison McAdams
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Aleksandra Igdalova
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Manuel Spitschan
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - David H. Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Geoffrey K. Aguirre
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States
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Ostrin LA. The ipRGC-driven pupil response with light exposure and refractive error in children. Ophthalmic Physiol Opt 2018; 38:503-515. [PMID: 30259538 DOI: 10.1111/opo.12583] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 09/08/2018] [Indexed: 11/30/2022]
Abstract
PURPOSE The intrinsically photosensitive retinal ganglion cells (ipRGCs) signal environmental light, control pupil size and entrain circadian rhythm. There is speculation that ipRGCs may be involved in the protective effects of light exposure in myopia. Here, the ipRGC-driven pupil response was evaluated in children and examined with light exposure and refractive error. METHODS Children ages 5-15 years participated. Subjects wore an actigraph device prior to the lab visit for objective measures of light exposure and sleep. For pupillometry, the left eye was dilated and presented with stimuli, and the consensual pupil response was measured in the right eye. Pupil measurements were preceded by 5 min dark adaptation. In Experiment 1 (n = 14), 1 s long wavelength light ('red,' 651 nm, 167 cd m-2 ) and 10 increasing intensities of 1 s short wavelength light ('blue,' 456 nm, 0.167-167 cd m-2 ) were presented with a 60 s interstimulus interval. A piecewise two-segment regression was fit to the stimulus response function to determine the functional melanopsin threshold. Pupil responses were analysed with light exposure over the previous 24 h. For Experiment 2 (n = 42), three 1 s red and three 1 s blue alternating stimuli were presented with a 60 s interstimulus interval. Following an additional 5-min dark adaption, the experiment was repeated. Pupil metrics included peak constriction, the 6 s and 30 s post-illumination response (PIPR), early and late area under the curve (AUC). Following pupil measurements, cycloplegic refractive error and axial length were measured. RESULTS For Experiment 1, PIPR metrics demonstrated a graded response to increasing intensity blue stimuli, with a mean functional melanopsin threshold of 6.2 ± 4.5 cd m-2 (range: 0.84-16.7 cd m-2 ). The 6 s PIPR and early AUC were associated with 24-h light exposure for high intensity stimuli (33.3 and 83.3 cd m-2 , p < 0.005 for both). For Experiment 2, there were no associations between pupil metrics and refractive error. The 6 s PIPR and early AUC to blue stimuli were significantly increased for Trial 2 compared to Trial 1. CONCLUSIONS The ipRGC-driven pupil responses in children were robust and similar to responses previously measured in an adult population. The 6 s PIPR and early AUC to high intensity blue stimuli were associated with previous light exposure. There were no associations between the ipRGC-driven pupil response and refractive status in this cohort.
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Affiliation(s)
- Lisa A Ostrin
- College of Optometry, University of Houston, Houston, USA
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33
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Feigl B, Ojha G, Hides L, Zele AJ. Melanopsin-Driven Pupil Response and Light Exposure in Non-seasonal Major Depressive Disorder. Front Neurol 2018; 9:764. [PMID: 30271376 PMCID: PMC6146094 DOI: 10.3389/fneur.2018.00764] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/23/2018] [Indexed: 11/13/2022] Open
Abstract
Background: Melanopsin-expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGCs) signal non-imaging forming effects of environmental light for circadian phoentrainment, the pupil light reflex, and mood regulation. In seasonal affective disorder, ipRGC dysfunction is thought to cause abberant transmission of the external illumination for photoentrainment. It is not known if patients with non-seasonal depression have abnormal melanospin mediated signaling and/or irregular environmental light exposure. Methods: Twenty-one adults who live in a sub-tropical region, including eight patients with non-seasonal depression and thirteen age-matched healthy controls were recruited. The Mini International Neuropsychiatry Interview diagnosed the presence of a major depressive disorder. Light exposure was determined using actigraphy over a 2 week period. The melanopsin mediated post-illumination pupil response (PIPR) and outer retinal inputs to ipRGCs (transient pupil response and maximum pupil constriction amplitude) were measured in response to 1 s, short and long wavelength light with high and low melanopsin excitation. Results: The mean daylight exposure as a function of clock hours and total light exposure duration (mins) to illumination levels commonly recommended for depression therapy were not significantly different between groups. Out of 84 pupil measurements (42 each in the depression and control groups), the melanopsin-mediated PIPR amplitude, transient pupil response, and pupil constriction amplitude were not significantly different between groups. Conclusions: This report provides initial evidence of normal melanopsin function and environmental light exposures in patients with pre-dominately mid and moderate non-seasonal depression in a subtropical location in the southern hemisphere.
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Affiliation(s)
- Beatrix Feigl
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.,Queensland Eye Institute, Brisbane, QLD, Australia
| | - Govinda Ojha
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Leanne Hides
- School of Psychology, University of Queensland, Brisbane, QLD, Australia
| | - Andrew J Zele
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.,School of Optometry and Vision Science, Queensland University of Technology, Brisbane, QLD, Australia
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Joyce DS, Feigl B, Kerr G, Roeder L, Zele AJ. Melanopsin-mediated pupil function is impaired in Parkinson's disease. Sci Rep 2018; 8:7796. [PMID: 29773814 PMCID: PMC5958070 DOI: 10.1038/s41598-018-26078-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 04/30/2018] [Indexed: 01/16/2023] Open
Abstract
Parkinson's disease (PD) is characterised by non-motor symptoms including sleep and circadian disruption. Melanopsin-expressing intrinsically photosensitive Retinal Ganglion Cells (ipRGC) transmit light signals to brain areas controlling circadian rhythms and the pupil light reflex. To determine if non-motor symptoms observed in PD are linked to ipRGC dysfunction, we evaluated melanopsin and rod/cone contributions to the pupil response in medicated participants with PD (n = 17) and controls (n = 12). Autonomic tone was evaluated by measuring pupillary unrest in darkness. In the PD group, there is evidence for an attenuated post-illumination pupil response (PIPR) amplitude and reduced pupil constriction amplitude, and PIPR amplitudes did not correlate with measures of sleep quality, retinal nerve fibre layer thickness, disease severity, or medication dosage. Both groups exhibited similar pupillary unrest. We show that melanopsin- and the rod/cone-photoreceptor contributions to the pupil control pathway are impaired in people with early-stage PD who have no clinically observable ophthalmic abnormalities. Given that ipRGCs project to brain targets involved in arousal, sleep and circadian rhythms, ipRGC dysfunction may underpin some of the non-motor symptoms observed in PD.
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Affiliation(s)
- Daniel S Joyce
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- Visual Science Laboratory, School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia
- Department of Psychiatry and Behavioral Sciences, School of Medicine, Stanford University, Stanford, USA
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- Medical Retina Laboratory, School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
- Queensland Eye Institute, Brisbane, Australia
| | - Graham Kerr
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- Movement Neuroscience Program, Queensland University of Technology (QUT), Brisbane, Australia
| | - Luisa Roeder
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- Movement Neuroscience Program, Queensland University of Technology (QUT), Brisbane, Australia
| | - Andrew J Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.
- Visual Science Laboratory, School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia.
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35
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Ba-Ali S, Jensen RH, Larsen LS, Lund-Andersen H, Hamann S. The Melanopsin-Mediated Pupillary Light Response Is Not Changed in Patients with Newly Diagnosed Idiopathic Intracranial Hypertension. Neuroophthalmology 2018; 42:65-72. [PMID: 29563950 DOI: 10.1080/01658107.2017.1344251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 06/07/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022] Open
Abstract
Previously, it has been reported that melanopsin-mediated pupillary light response (PLR), measured with pupillometry, is reduced in patients with idiopathic intracranial hypertension (IIH), indicating the clinical utility of the tool in the diagnosis of IIH. In the current study, the authors aimed to measure the PLR in 13 treatment-naive patients with new-onset IIH and 13 healthy controls. In contrast to the previous report, which was based on patients with longstanding IIH (n = 13), the authors found no significant difference in the melanopsin-mediated PLR (p = 0.48).
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Affiliation(s)
- Shakoor Ba-Ali
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rigmor Højland Jensen
- Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Neurology, Danish Headache Center, Rigshospitalet, Glostrup, Denmark
| | - Line Sofie Larsen
- Department of Neurology, Danish Headache Center, Rigshospitalet, Glostrup, Denmark
| | - Henrik Lund-Andersen
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steffen Hamann
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Abstract
The pupillary light reflex (PLR) describes the constriction and subsequent dilation of the pupil in response to light as a result of the antagonistic actions of the iris sphincter and dilator muscles. Since these muscles are innervated by the parasympathetic and sympathetic nervous systems, respectively, different parameters of the PLR can be used as indicators for either sympathetic or parasympathetic modulation. Thus, the PLR provides an important metric of autonomic nervous system function that has been exploited for a wide range of clinical applications. Measurement of the PLR using dynamic pupillometry is now an established quantitative, non-invasive tool in assessment of traumatic head injuries. This review examines the more recent application of dynamic pupillometry as a diagnostic tool for a wide range of clinical conditions, varying from neurodegenerative disease to exposure to toxic chemicals, as well as its potential in the non-invasive diagnosis of infectious disease.
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Affiliation(s)
- Charlotte A Hall
- Research Centre for Topical Drug Delivery and Toxicology, University of Hertfordshire, Hatfield SP10 1JX, UK.
| | - Robert P Chilcott
- Research Centre for Topical Drug Delivery and Toxicology, University of Hertfordshire, Hatfield SP10 1JX, UK.
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37
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Zele AJ, Feigl B, Adhikari P, Maynard ML, Cao D. Melanopsin photoreception contributes to human visual detection, temporal and colour processing. Sci Rep 2018; 8:3842. [PMID: 29497109 PMCID: PMC5832793 DOI: 10.1038/s41598-018-22197-w] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 02/14/2018] [Indexed: 12/27/2022] Open
Abstract
The visual consequences of melanopsin photoreception in humans are not well understood. Here we studied melanopsin photoreception using a technique of photoreceptor silent substitution with five calibrated spectral lights after minimising the effects of individual differences in optical pre-receptoral filtering and desensitising penumbral cones in the shadow of retinal blood vessels. We demonstrate that putative melanopsin-mediated image-forming vision corresponds to an opponent S-OFF L + M-ON response property, with an average temporal resolution up to approximately 5 Hz, and >10x higher thresholds than red-green colour vision. With a capacity for signalling colour and integrating slowly changing lights, melanopsin-expressing intrinsically photosensitive retinal ganglion cells maybe the fifth photoreceptor type for peripheral vision.
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Affiliation(s)
- Andrew J Zele
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia.
| | - Beatrix Feigl
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
- Queensland Eye Institute, Brisbane, Australia
| | - Prakash Adhikari
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia
| | - Michelle L Maynard
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
- School of Optometry and Vision Science, Queensland University of Technology (QUT), Brisbane, Australia
- School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
| | - Dingcai Cao
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, USA
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38
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Ba-Ali S, Lund-Andersen H, Ahmadi H, Brøndsted AE. Effect of Intermittent versus Continuous Light Exposure on Pupillary Light Response, As Evaluated by Pupillometry. Front Neurol 2018; 8:746. [PMID: 29387040 PMCID: PMC5775973 DOI: 10.3389/fneur.2017.00746] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 12/26/2017] [Indexed: 12/11/2022] Open
Abstract
Objective Continuous and intermittent stimuli with green light affect the pupillary light response (PLR) differently. Since the majority of pupillometric studies use blue and red lights, we investigated the effect of continuous and intermittent stimulations on the PLR using red and blue lights. Methods Seventeen healthy subjects underwent continuous- and intermittent light stimuli, using red (643 nm) and blue light (463 nm). To avoid the influence of pupil size on the amount of light entering the eye, the procedures were repeated with the stimulus–eye in dilated condition. The maximal pupillary constriction and the early redilation phase of post-illumination pupillary response (PIPREarly) represented the mixed response of melanopsin and rod–cone photoreceptors. The late redilation phase of PIPR (PIPRLate) was the marker of melanopsin-containing retinal ganglion cells. Results Intermittent stimuli with blue light elicited significantly larger maximal contraction during dilated condition (P = 0.001), and larger sustained pupillary contraction under dilated as well as undilated condition (P < 0.001) compared to continuous light exposure. Except the PIPREarly during undilated condition, none of the PIPR metrics were significantly different between intermittent and continuous blue light stimuli. Intermittent red light stimuli elicited also a more sustained pupillary contraction regardless of mydriatic instillation (P ≤ 0.02). In addition, intermittent red light exposure resulted in a slightly larger PIPREarly under undilated condition (P = 0.02) and a slightly larger PIPRLate under dilated condition (P = 0.049). Except the PIPRLate to continuous red light stimulus, all PIPR parameters were larger when the light was presented after induction of unilateral mydriasis. Conclusion PLR parameters during and after light exposures depend on both the light stimulation mode and the entrance pupillary size.
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Affiliation(s)
- Shakoor Ba-Ali
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Lund-Andersen
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hamid Ahmadi
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Adam Elias Brøndsted
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark.,Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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B-mode ultrasound assessment of pupillary function: Feasibility, reliability and normal values. PLoS One 2017; 12:e0189016. [PMID: 29211788 PMCID: PMC5718517 DOI: 10.1371/journal.pone.0189016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 11/18/2017] [Indexed: 11/19/2022] Open
Abstract
Purpose To evaluate B-mode ultrasound as a novel method for the examination of pupillary function and to provide normal values for the pupillary reflex as assessed by B-mode ultrasound. Methods 100 subjects (49 female, 51 male, mean [range] age 51 [18–80 years]) with no history of ophthalmologic disease, no clinically detectable pupillary defects, and corrected visual acuity ≥ 0.8 were included in this prospective observational study. B-mode ultrasound was performed with the subjects eyes closed using an Esaote-Mylab25 system according to current guidelines for orbital insonation. A standardized light stimulus was applied. Results The mean ± standard deviation left and right pupillary diameters (PD) at rest were 4.7 ± 0.8 and 4.5 ± 0.8 mm. Following an ipsilateral light stimulus (Lstim), left and right constricted PD were 2.8 ± 0.6 and 2.7 ± 0.6 mm. Following a contralateral Lstim, left and right constricted PD were 2.7 ± 0.6 and 2.6 ± 0.5 mm. Left and right pupillary constriction time (PCT) following ipsilateral Lstim were 970 ± 261.6 and 967 ± 220 ms. Left and right PCT following a contralateral Lstim were 993.8 ± 192.6 and 963 ± 189.4 ms. Patient age was inversely correlated with PD at rest and with PD after ipsilateral and contralateral Lstim (all p<0.001), but not with PCT. Conclusions B-mode ultrasound is a simple, rapid and objective method for the quantitative assessment of pupillary function, which may prove useful in a variety of settings where eyelid retraction is impeded or an infrared pupillometry device is unavailable.
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Charng J, Jacobson SG, Heon E, Roman AJ, McGuigan DB, Sheplock R, Kosyk MS, Swider M, Cideciyan AV. Pupillary Light Reflexes in Severe Photoreceptor Blindness Isolate the Melanopic Component of Intrinsically Photosensitive Retinal Ganglion Cells. Invest Ophthalmol Vis Sci 2017; 58:3215-3224. [PMID: 28660274 PMCID: PMC5490362 DOI: 10.1167/iovs.17-21909] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose Pupillary light reflex (PLR) is driven by outer retinal photoreceptors and by melanopsin-expressing intrinsically photosensitive retinal ganglion cells of the inner retina. To isolate the melanopic component, we studied patients with severe vision loss due to Leber congenital amaurosis (LCA) caused by gene mutations acting on the outer retina. Methods Direct PLR was recorded in LCA patients (n = 21) with known molecular causation and severe vision loss. Standard stimuli (2.5 log scot-cd.m−2; ∼13 log quanta.cm−2.s−1; achromatic full-field) with 0.1- or 5-second duration were used in all patients. Additional recordings were performed with higher luminance (3.9 log scot-cd.m−2) in a subset of patients. Results The LCA patients showed no detectable PLR to the standard stimulus with short duration. With longer-duration stimuli, a PLR was detectable in the majority (18/21) of patients. The latency of the PLR was 2.8 ± 1.3 seconds, whereas normal latency was 0.19 ± 0.02 seconds. Peak contraction amplitude in patients was 1.1 ± 0.9 mm at 6.2 ± 2.3 seconds, considerably different from normal amplitude of 4.2 ± 0.4 mm at 3.0 ± 0.4 seconds. Recordings with higher luminance demonstrated that PLRs in severe LCA could also be evoked with short-duration stimuli. Conclusions The PLR in severe LCA patients likely represents the activation of the melanopic circuit in isolation from rod and cone input. Knowledge of the properties of the human melanopic PLR allows not only comparison to those in animal models but also serves to define the fidelity of postretinal transmission in clinical trials targeting patients with no outer retinal function.
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Affiliation(s)
- Jason Charng
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Alejandro J Roman
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - David B McGuigan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Mychajlo S Kosyk
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Malgorzata Swider
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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41
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Park JC, Chen YF, Blair NP, Chau FY, Lim JI, Leiderman YI, Shahidi M, McAnany JJ. Pupillary responses in non-proliferative diabetic retinopathy. Sci Rep 2017; 7:44987. [PMID: 28332564 PMCID: PMC5362954 DOI: 10.1038/srep44987] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 02/17/2017] [Indexed: 01/24/2023] Open
Abstract
The goal of this study was to determine the extent of rod-, cone-, and melanopsin-mediated pupillary light reflex (PLR) abnormalities in diabetic patients who have non-proliferative diabetic retinopathy (NPDR). Fifty diabetic subjects who have different stages of NPDR and 25 age-equivalent, non-diabetic controls participated. PLRs were measured in response to full-field, brief-flash stimuli under conditions that target the rod, cone, and intrinsically-photosensitive (melanopsin) retinal ganglion cell pathways. Pupil responses were compared among the subjects groups using age-corrected linear mixed models. Compared to control, the mean baseline pupil diameters were significantly smaller for all patient groups in the dark (all p < 0.001) and for the moderate-severe NPDR group in the light (p = 0.003). Pairwise comparisons indicated: (1) the mean melanopsin-mediated PLR was significantly reduced in the mild and moderate-severe groups (both p < 0.001); (2) the mean cone-mediated PLR was reduced significantly in the moderate-severe group (p = 0.008); (3) no significant differences in the mean rod-mediated responses. The data indicate abnormalities in NPDR patients under conditions that separately assess pupil function driven by different photoreceptor classes. The results provide evidence for compromised neural function in these patients and provide a promising approach for quantifying their neural abnormalities.
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Affiliation(s)
- Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
| | - Yi-Fan Chen
- Center for Clinical and Translational Sciences, University of Illinois at Chicago, 914 S Wood Street, Chicago, IL 60612, USA
| | - Norman P Blair
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
| | - Felix Y Chau
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
| | - Jennifer I Lim
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
| | - Yannek I Leiderman
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
| | - Mahnaz Shahidi
- Department of Ophthalmology, University of Southern California, 1450 San Pablo St, Los Angeles, CA 90033, USA
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL 60612, USA
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Ishibashi F, Kojima R, Taniguchi M, Kosaka A, Uetake H, Tavakoli M. The Preferential Impairment of Pupil Constriction Stimulated by Blue Light in Patients with Type 2 Diabetes without Autonomic Neuropathy. J Diabetes Res 2017; 2017:6069730. [PMID: 28421205 PMCID: PMC5380853 DOI: 10.1155/2017/6069730] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/12/2016] [Accepted: 02/23/2017] [Indexed: 12/14/2022] Open
Abstract
The main aim of the present paper is to examine whether the pupillary light reflex (PLR) mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) is impaired in type 2 diabetic patients. One hundred and three diabetic patients without diabetic autonomic neuropathy (DAN) and 42 age-matched controls underwent a series of detailed neurological examinations. The patients were stratified into three groups: stage I, no neuropathy; stage II, asymptomatic neuropathy; stage III, symptomatic but without DAN. The PLR to 470 and 635 nm light at 20 cd/m2 was recorded. Small fiber neuropathy was assessed by corneal confocal microscopy and quantifying corneal nerve fiber (CNF) morphology. The 470 nm light induced a stronger and faster PLR than did 635 nm light in all subjects. The PLR to both lights was impaired equally across all of the diabetic subgroups. The postillumination pupil response (PIPR) after 470 nm light offset at ≥1.7 sec was attenuated in diabetic patients without differences between subgroups. Receiver operating characteristic analysis revealed that the PIPR mediated by ipRGCs in patients with stage II and stage III neuropathy was different from that of the control subjects. Clinical factors, nerve conduction velocity, and CNF measures were significantly correlated with PLR parameters with 470 nm light. PLR kinetics were more impaired by stimulation with blue light than with red light in diabetic patients without DAN.
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Affiliation(s)
| | | | | | | | | | - Mitra Tavakoli
- University of Exeter Medical School, Exeter, UK
- *Mitra Tavakoli:
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43
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Adhikari P, Zele AJ, Thomas R, Feigl B. Quadrant Field Pupillometry Detects Melanopsin Dysfunction in Glaucoma Suspects and Early Glaucoma. Sci Rep 2016; 6:33373. [PMID: 27622679 PMCID: PMC5020729 DOI: 10.1038/srep33373] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 08/23/2016] [Indexed: 12/20/2022] Open
Abstract
It is difficult to detect visual function deficits in patients at risk for glaucoma (glaucoma suspects) and at early disease stages with conventional ophthalmic tests such as perimetry. To this end, we introduce a novel quadrant field measure of the melanopsin retinal ganglion cell mediated pupil light response corresponding with typical glaucomatous arcuate visual field defects. The melanopsin-mediated post-illumination pupil response (PIPR) was measured in 46 patients with different stages of glaucoma including glaucoma suspects and compared to a healthy group of 21 participants with no disease. We demonstrate that the superonasal quadrant PIPR differentiated glaucoma suspects and early glaucoma patients from controls with fair (AUC = 0.74) and excellent (AUC = 0.94) diagnostic accuracy, respectively. The superonasal PIPR provides a linear functional correlate of structural retinal nerve fibre thinning in glaucoma suspects and early glaucoma patients. This first report that quadrant PIPR stimulation detects melanopsin dysfunction in patients with early glaucoma and at pre-perimetric stages may have future implications in treatment decisions of glaucoma suspects.
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Affiliation(s)
- Prakash Adhikari
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Brisbane, QLD, 4059, Australia
- School of Optometry and Vision Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Andrew J. Zele
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Brisbane, QLD, 4059, Australia
- School of Optometry and Vision Science, Queensland University of Technology, Brisbane, QLD, Australia
| | - Ravi Thomas
- Queensland Eye Institute, South Brisbane, QLD, Australia
- University of Queensland, Brisbane, QLD, Australia
| | - Beatrix Feigl
- Medical Retina and Visual Science Laboratories, Institute of Health and Biomedical Innovation, Queensland University of Technology, 60 Musk Avenue, Brisbane, QLD, 4059, Australia
- Queensland Eye Institute, South Brisbane, QLD, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
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