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Sánchez-Fernández C, Del Olmo-Aguado S, Artime E, Barros A, Fernández-Vega Cueto L, Merayo-Lloves J, Alcalde I. Immunocytochemical Analysis of Crocin against Oxidative Stress in Trigeminal Sensory Neurons Innervating the Cornea. Molecules 2024; 29:456. [PMID: 38257369 PMCID: PMC10818698 DOI: 10.3390/molecules29020456] [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: 10/27/2023] [Revised: 12/15/2023] [Accepted: 01/15/2024] [Indexed: 01/24/2024] Open
Abstract
Corneal diseases are a major cause of vision loss, often associated with aging, trauma and disease. Damage to corneal sensory innervation leads to discomfort and pain. Environmental stressors, such as short-wavelength light, can induce oxidative stress that alters mitochondrial function and affects cell and tissue homeostasis, including corneal innervation. Cellular antioxidant mechanisms may attenuate oxidative stress. This study investigates crocin, a derivative of saffron, as a potential antioxidant therapy. In vitro rat trigeminal sensory ganglion neurons were exposed to both sodium azide and blue light overexposure as a model of oxidative damage. Crocin was used as a neuroprotective agent. Mitochondrial and cytoskeletal markers were studied by immunofluorescence analysis to determine oxidative damage and neuroprotection. In vivo corneal innervation degeneration was evaluated in cornea whole mount preparations using Sholl analyses. Blue light exposure induces oxidative stress that affects trigeminal neuron mitochondria and alters sensory axon dynamics in vitro, and it also affects corneal sensory innervation in an in vivo model. Our results show that crocin was effective in preserving mitochondrial function and protecting corneal sensory neurons from oxidative stress. Crocin appears to be a promising candidate for the neuroprotection of corneal innervation.
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Affiliation(s)
- Cristina Sánchez-Fernández
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Susana Del Olmo-Aguado
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Enol Artime
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Alberto Barros
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
| | - Luis Fernández-Vega Cueto
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Jesús Merayo-Lloves
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Ignacio Alcalde
- Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, 33012 Oviedo, Spain; (C.S.-F.); (S.D.O.-A.); (E.A.); (A.B.); (L.F.-V.C.); (J.M.-L.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
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2
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Asiedu K. Neurophysiology of corneal neuropathic pain and emerging pharmacotherapeutics. J Neurosci Res 2024; 102:e25285. [PMID: 38284865 DOI: 10.1002/jnr.25285] [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: 08/09/2023] [Revised: 11/12/2023] [Accepted: 12/02/2023] [Indexed: 01/30/2024]
Abstract
The altered activity generated by corneal neuronal injury can result in morphological and physiological changes in the architecture of synaptic connections in the nervous system. These changes can alter the sensitivity of neurons (both second-order and higher-order projection) projecting pain signals. A complex process involving different cell types, molecules, nerves, dendritic cells, neurokines, neuropeptides, and axon guidance molecules causes a high level of sensory rearrangement, which is germane to all the phases in the pathomechanism of corneal neuropathic pain. Immune cells migrating to the region of nerve injury assist in pain generation by secreting neurokines that ensure nerve depolarization. Furthermore, excitability in the central pain pathway is perpetuated by local activation of microglia in the trigeminal ganglion and alterations of the descending inhibitory modulation for corneal pain arriving from central nervous system. Corneal neuropathic pain may be facilitated by dysfunctional structures in the central somatosensory nervous system due to a lesion, altered synaptogenesis, or genetic abnormality. Understanding these important pathways will provide novel therapeutic insight.
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Affiliation(s)
- Kofi Asiedu
- School of Optometry & Vision Science, University of New South Wales, Sydney, New South Wales, Australia
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3
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Ayaki M, Kuze M, Negishi K. Association of eye strain with dry eye and retinal thickness. PLoS One 2023; 18:e0293320. [PMID: 37862343 PMCID: PMC10588844 DOI: 10.1371/journal.pone.0293320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/09/2023] [Indexed: 10/22/2023] Open
Abstract
PURPOSE The purpose of this cohort study was to investigate the association between the prevalence of abnormal ocular examination results and the common visual symptoms of eye strain, blurred vision and photophobia. METHODS Consecutive first-visit outpatients with best-corrected visual acuity better than 20/30 in both eyes were enrolled and those with a history of intra-ocular lens implantation and glaucoma were excluded. Dry eye-related examinations and retinal thickness measurement were conducted. The odds ratio (OR) was calculated with logistic regression analyses of ocular data in relation to the presence of visual symptoms. RESULTS A total of 6078 patients (3920 women, mean age 49.0 ± 20.4 years) were analyzed. The prevalence of each symptom was 31.8% for eye strain, 22.5% for blurred vision and 16.0% for photophobia. A significant risk factor for eye strain was short tear break-up time (TBUT) (OR 1.88), superficial punctate keratitis (SPK) (OR 1.44), and thickness of ganglion cell complex (GCC) (OR 1.30). Risk factors for blurred vision were short TBUT (OR 1.85), SPK (OR 1.24) and GCC (OR 0.59). Risk factors for photophobia were short TBUT (OR 1.77) and SPK (OR 1.32). Schirmer test value, peripapillary nerve fiber layer thickness and full macular thickness were not associated with the tested symptoms. CONCLUSION The current study successfully identified female gender, short TBUT, and SPK as significant risk factors for eye strain, blurred vision, and photophobia with considerable ORs.
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Affiliation(s)
- Masahiko Ayaki
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- Otake Eye Clinic, Kanagawa, Japan
| | | | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
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4
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Moulton EA, Galor A, Ciolino JB, Jacobs DS. Is blue light a red herring in a rodent model of "computer vision syndrome"? Pain 2023; 164:1640. [PMID: 37326461 PMCID: PMC10287036 DOI: 10.1097/j.pain.0000000000002941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Affiliation(s)
- Eric A Moulton
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Anat Galor
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Joseph B Ciolino
- Cornea and Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States
| | - Deborah S Jacobs
- Cornea and Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, United States
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5
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Gao N, Lee PSY, Zhang J, Yu FSX. Ocular nociception and neuropathic pain initiated by blue light stress in C57BL/6J mice. Pain 2023; 164:1616-1626. [PMID: 37093736 PMCID: PMC10277230 DOI: 10.1097/j.pain.0000000000002896] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/03/2023] [Indexed: 04/25/2023]
Abstract
To elucidate the physiological, cellular, and molecular mechanisms responsible for initiating and sustaining ocular neuropathic pain, we created a blue-light-exposure model in C57BL/6 mice. Mice were exposed to 12 h of blue or white light followed by 12 h of darkness. Before blue light exposure, baseline tear secretion, stability, and ocular hyperalgesia were assessed by measuring hyper- or hypo-osmotic solution-induced eye wiping, wind-induced eye closing, and cold-induced eye blinking. At 1 day post-blue light exposure, alterations in hypotonic/hypertonic-induced eye-wiping, and tear film abnormalities were observed. Eye-wiping behaviors were abolished by topical anesthesia. The cold-stimulated eye-blinking and wind-stimulated eye-closing behaviors began after day 3 and their frequency further increased after day 9. Blue-light exposure reduced the density of nerve endings, and increased their tortuosity, the number of beadlike structures, and the branching of stromal nerve fibers, as assessed by whole-mount confocal microscopy. Blue-light exposure also increased TRPV1, but not TRPV4 staining intensity of corneal-projecting neurons in the trigeminal ganglia, as detected by Fluorogold retrograde labeling and immunohistochemistry. TRPV1 and substance P expression was increased, whereas CGRP expression deceased at the mRNA level in isolated corneal projecting neurons. Hence, our blue-light exposure B6 mouse model for assessing tearing and ocular hyperalgesia is useful for studying ocular pain and its underlying mechanisms. Blue-light-induced alterations in tearing and ocular hyperalgesia may be related to the elevated expression of TRPV1, SP, and/or the suppressed expression of CGRP at the ocular surface.
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Affiliation(s)
- Nan Gao
- Department of Ophthalmology, Visual and Anatomical
Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Patrick S. Y. Lee
- Department of Ophthalmology, Visual and Anatomical
Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Jitao Zhang
- Biomedical Engineering Department, Wayne State University.
6135 Woodward Ave, Integrative Biosciences Center, Detroit, MI, 48202
| | - Fu-shin X. Yu
- Department of Ophthalmology, Visual and Anatomical
Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
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6
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Gao N, Yu FSX. Reply to Moulton et al. Pain 2023; 164:1641. [PMID: 37326462 PMCID: PMC10443905 DOI: 10.1097/j.pain.0000000000002942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Affiliation(s)
- Nan Gao
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Fu-shin X. Yu
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI 48201, USA
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7
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Hammond B, Gogniat M, Buch J, Miller LS. Strategic filtering of high-energy visible light expands neural correlates of functional vision particularly in older participants. Heliyon 2023; 9:e17271. [PMID: 37539228 PMCID: PMC10394902 DOI: 10.1016/j.heliyon.2023.e17271] [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: 09/21/2022] [Revised: 05/18/2023] [Accepted: 06/13/2023] [Indexed: 08/05/2023] Open
Abstract
In this study we assessed the neural correlates of functional vision while varying patterns of light filtration. Four filter conditions used relatively flat filtering across the visible spectrum while one filter was a step filter that selectively absorbed violet light (wavelengths below about 415 nm). Neural effects were quantified by measuring the BOLD response ((T2*-based fMRI) while subjects performed a challenging visual task (judging gap direction in Landolt Cs that randomly varied in size). In general (based on p < 0.01 directional criterion not corrected for aggregated error), as filtering increased (less interference by bright light), brain activity associated with the task also increased. This effect, even using the most conservative statistics, was most evident when using the violet filter (especially for the older subjects) despite only reducing the very highest energy portion of the visible spectrum. This finding suggests that filtering can increase neural activity associated with functional vision; such effects might be achievable through filtering just the highest visible energy (violet).
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Affiliation(s)
- Billy Hammond
- Vision Sciences Laboratory, Behavioral and Brain Sciences Program, Department of Psychology, University of Georgia, Athens, GA, USA
| | - Marissa Gogniat
- Vanderbilt Memory & Alzheimer's Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John Buch
- Research & Development, Johnson & Johnson Vision Care Inc., Jacksonville, FL, USA
| | - L. Stephen Miller
- Neuropsychology and Memory Assessment Laboratory, Department of Psychology, University of Georgia, USA
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8
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Reyes N, Huang JJ, Choudhury A, Pondelis N, Locatelli EV, Felix ER, Pattany PM, Galor A, Moulton EA. Botulinum toxin A decreases neural activity in pain-related brain regions in individuals with chronic ocular pain and photophobia. Front Neurosci 2023; 17:1202341. [PMID: 37404468 PMCID: PMC10315909 DOI: 10.3389/fnins.2023.1202341] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 06/05/2023] [Indexed: 07/06/2023] Open
Abstract
Introduction To examine the effect of botulinum toxin A (BoNT-A) on neural mechanisms underlying pain and photophobia using functional magnetic resonance imaging (fMRI) in individuals with chronic ocular pain. Methods Twelve subjects with chronic ocular pain and light sensitivity were recruited from the Miami Veterans Affairs eye clinic. Inclusion criteria were: (1) chronic ocular pain; (2) presence of ocular pain over 1 week recall; and (3) presence of photophobia. All individuals underwent an ocular surface examination to capture tear parameters before and 4-6 weeks after BoNT-A injections. Using an event-related fMRI design, subjects were presented with light stimuli during two fMRI scans, once before and 4-6 weeks after BoNT-A injection. Light evoked unpleasantness ratings were reported by subjects after each scan. Whole brain blood oxygen level dependent (BOLD) responses to light stimuli were analyzed. Results At baseline, all subjects reported unpleasantness with light stimulation (average: 70.8 ± 32.0). Four to six weeks after BoNT-A injection, unpleasantness scores decreased (48.1 ± 33.6), but the change was not significant. On an individual level, 50% of subjects had decreased unpleasantness ratings in response to light stimulation compared to baseline ("responders," n = 6), while 50% had equivalent (n = 3) or increased (n = 3) unpleasantness ("non-responders"). At baseline, several differences were noted between responders and non-responders; responders had higher baseline unpleasantness ratings to light, higher symptoms of depression, and more frequent use of antidepressants and anxiolytics, compared to non-responders. Group analysis at baseline displayed light-evoked BOLD responses in bilateral primary somatosensory (S1), bilateral secondary somatosensory (S2), bilateral anterior insula, paracingulate gyrus, midcingulate cortex (MCC), bilateral frontal pole, bilateral cerebellar hemispheric lobule VI, vermis, bilateral cerebellar crus I and II, and visual cortices. BoNT-A injections significantly decreased light evoked BOLD responses in bilateral S1, S2 cortices, cerebellar hemispheric lobule VI, cerebellar crus I, and left cerebellar crus II. BoNT-A responders displayed activation of the spinal trigeminal nucleus at baseline where non-responders did not. Discussion BoNT-A injections modulate light-evoked activation of pain-related brain systems and photophobia symptoms in some individuals with chronic ocular pain. These effects are associated with decreased activation in areas responsible for processing the sensory-discriminative, affective, dimensions, and motor responses to pain.
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Affiliation(s)
- Nicholas Reyes
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Jaxon J. Huang
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Anjalee Choudhury
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Nicholas Pondelis
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesia, Critical Care and Pain Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
| | - Elyana V. Locatelli
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Elizabeth R. Felix
- Research Service, Miami Veterans Administration Medical Center, Miami, FL, United States
- Physical Medicine and Rehabilitation, University of Miami, Miami, FL, United States
| | - Pradip M. Pattany
- Department of Radiology, University of Miami, Miami, FL, United States
| | - Anat Galor
- Surgical Services, Miami Veterans Administration Medical Center, Miami, FL, United States
- Bascom Palmer Eye Institute, University of Miami, Miami, FL, United States
| | - Eric A. Moulton
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesia, Critical Care and Pain Medicine, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
- Department of Ophthalmology, Boston Children’s Hospital and Harvard Medical School, Boston, MA, United States
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9
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Galor A, Hamrah P, Haque S, Attal N, Labetoulle M. Understanding chronic ocular surface pain: An unmet need for targeted drug therapy. Ocul Surf 2022; 26:148-156. [PMID: 35970433 DOI: 10.1016/j.jtos.2022.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/29/2022] [Accepted: 08/09/2022] [Indexed: 10/15/2022]
Abstract
Chronic ocular surface pain (COSP) may be defined as a feeling of pain, perceived as originating from the ocular surface, that persists for >3 months. COSP is a complex multifactorial condition associated with several risk factors that may significantly interfere with an individual's daily activities, resulting in poor quality of life (QoL). COSP is also likely to have a high burden on patients with substantial implications on global healthcare costs. While patients may use varied terminology to describe symptoms of COSP, any ocular surface damage in the ocular sensory apparatus (nociceptive, neuropathic, inflammatory, or combination thereof) resulting in low tear production, chronic inflammation, or nerve abnormalities (functional and/or morphological), is typically associated with COSP. Considering the heterogeneity of this condition, it is highly recommended that advanced multimodal diagnostic tools are utilized to help discern the nociceptive and neuropathic pain pathways in order to provide targeted treatment and effective clinical management. The current article provides an overview of COSP, including its multifactorial pathophysiology, etiology, prevalence, clinical presentation, impact on QoL, diagnosis, current management, and unmet medical needs.
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Affiliation(s)
- Anat Galor
- Surgical Services, Miami Veterans Affairs Medical Centre and Bascom Palmer Eye Institute, University of Miami, Miami, FL, USA
| | - Pedram Hamrah
- Tufts Medical Centre, New England Eye Center, 260 Tremont Street Biewend Building, Boston, MA, USA
| | | | - Nadine Attal
- CHU Paris IdF Ouest - Hôpital Ambroise Paré, 9 avenue Charles de Gaulle, 92100, Boulogne-Billancourt, INSERM U 987 and Université Paris Saclay, France
| | - Marc Labetoulle
- Service d'Ophtalmologie, hôpital Bicêtre, AP-HP, Université Paris Saclay, 94275, Le Kremlin-Bicêtre, France; IMVA-HB/IDMI, CEA, Inserm U1184, 92265, Fontenay-aux-Roses, France.
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10
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Wong NA, Bahmani H. A review of the current state of research on artificial blue light safety as it applies to digital devices. Heliyon 2022; 8:e10282. [PMID: 36042717 PMCID: PMC9420367 DOI: 10.1016/j.heliyon.2022.e10282] [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: 01/06/2022] [Revised: 05/13/2022] [Accepted: 08/09/2022] [Indexed: 12/24/2022] Open
Abstract
Light is necessary for human health and well-being. As we spend more time indoors, we are being increasingly exposed to artificial light. The development of artificial lighting has allowed us to control the brightness, colour, and timing of our light exposure. Yet, the widespread use of artificial light has raised concerns about the impact of altering our light environment on our health. The widespread adoption of personal digital devices over the past decade has exposed us to yet another source of artificial light. We spend a significant amount of time using digital devices with light-emitting screens, including smartphones and tablets, at close range. The light emitted from these devices, while appearing white, has an emission spectrum with a peak in the blue range. Blue light is often characterised as hazardous as its photon energy is higher than that of other wavelengths of visible light. Under certain conditions, visible blue light can cause harm to the retina and other ocular structures. Blue light can also influence the circadian rhythm and processes mediated by melanopsin-expressing intrinsically photosensitive retinal ganglion cells. While the blue component of sunlight is necessary for various physiological processes, whether the low-illuminance artificial blue light emitted from digital devices presents a risk to our health remains an ongoing area of debate. As technological advancements continue, it is relevant to understand how new devices may influence our well-being. This review examines the existing research on artificial blue light safety and the eye, visual performance, and circadian functions.
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Affiliation(s)
| | - Hamed Bahmani
- Dopavision GmbH, Berlin, Germany.,Department of Physiology of Cognitive Processes, Max Planck Institute for Biological Cybernetics, Tuebingen, Germany
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11
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Wang Y, Wang S, Qiu T, Xiao Z. Photophobia in headache disorders: characteristics and potential mechanisms. J Neurol 2022; 269:4055-4067. [PMID: 35322292 DOI: 10.1007/s00415-022-11080-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/10/2022] [Accepted: 03/10/2022] [Indexed: 01/23/2023]
Abstract
Photophobia is present in multiple types of headache disorders. The coexistence of photophobia and headache suggested the potential reciprocal interactions between visual and pain pathways. In this review, we summarized the photophobic characteristics in different types of headache disorders in the context of the three diagnostic categories of headache disorders: (1) primary headaches: migraine, tension-type headache, and trigeminal autonomic cephalalgias; (2) secondary headaches: headaches attributed to traumatic brain injury, meningitis, non-traumatic subarachnoid hemorrhage and disorder of the eyes; (3) painful cranial neuropathies: trigeminal neuralgia and painful optic neuritis. We then discussed potential mechanisms for the coexistence of photophobia and headache. In conclusion, the characteristics of photophobia are different among these headache disorders. The coexistence of photophobia and headache is associated with the interactions between visual and pain pathway at retina, midbrain, thalamus, hypothalamus and visual cortex. The communication between these pathways may depend on calcitonin gene-related peptide and pituitary cyclase-activating polypeptide transmission. Moreover, cortical spreading depression, an upstream trigger of headache, also plays an important role in photophobia by increased nociceptive input to the thalamus.
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Affiliation(s)
- Yajuan Wang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Shaoyang Wang
- Department of Emergency, Rizhao People's Hospital, Rizhao, 276800, Shandong, China
| | - Tao Qiu
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Zheman Xiao
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
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12
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Zaman S, Kane T, Katta M, Georgiou M, Michaelides M. Photoaversion in inherited retinal diseases: clinical phenotypes, biological basis, and qualitative and quantitative assessment. Ophthalmic Genet 2021; 43:143-151. [PMID: 34957896 DOI: 10.1080/13816810.2021.2015789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Severe light sensitivity is a feature common to a range of ophthalmological and neurological diseases. In inherited retinal diseases (IRDs) particularly, this may be accompanied by significant visual disruption. These symptoms are extremely debilitating for affected individuals and have significant implications in terms of day-to-day activities. Underlying mechanisms remain to be fully elucidated. Currently, there are many assessments of photoaversion (PA), however, all have limitations, with quantitative measurement in particular needing further evaluation. To understand the complexities associated with photoaversion from different pathologies, qualitative and quantitative assessments of the light aversion response must be standardized. There is no treatment to date, and strategies to alleviate symptoms focus on light avoidance. With respect to IRDs, however, gene therapy is currently being investigated in clinical trials and promising and further treatments may be on the horizon. The better characterization of these symptoms is an important end point measure in IRD gene therapy trials.
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Affiliation(s)
- Serena Zaman
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, University College London, London, UK
| | - Thomas Kane
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, University College London, London, UK
| | - Mohamed Katta
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, University College London, London, UK
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, University College London, London, UK
| | - Michel Michaelides
- Moorfields Eye Hospital, London, UK.,UCL Institute of Ophthalmology, University College London, London, UK
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13
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Kaiser EA, McAdams H, Igdalova A, Haggerty EB, Cucchiara BL, Brainard DH, Aguirre GK. Reflexive Eye Closure in Response to Cone and Melanopsin Stimulation: A Study of Implicit Measures of Light Sensitivity in Migraine. Neurology 2021; 97:e1672-e1680. [PMID: 34493620 DOI: 10.1212/wnl.0000000000012734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 08/16/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES To quantify interictal photophobia in migraine with and without aura using reflexive eye closure as an implicit measure of light sensitivity and to assess the contribution of melanopsin and cone signals to these responses. METHODS Participants were screened to meet criteria for 1 of 3 groups: headache-free (HF) controls, migraine without aura (MO), and migraine with visual aura (MA). MO and MA participants were included if they endorsed ictal and interictal photophobia. Exclusion criteria included impaired vision, inability to collect usable pupillometry, and history of either head trauma or seizure. Participants viewed light pulses that selectively targeted melanopsin, the cones, or their combination during recording of orbicularis oculi EMG (OO-EMG) and blinking activity. RESULTS We studied 20 participants in each group. MA and MO groups reported increased visual discomfort to light stimuli (discomfort rating, 400% contrast, MA: 4.84 [95% confidence interval 0.33, 9.35]; MO: 5.23 [0.96, 9.50]) as compared to HF controls (2.71 [0, 6.47]). Time course analysis of OO-EMG and blinking activity demonstrated that reflexive eye closure was tightly coupled to the light pulses. The MA group had greater OO-EMG and blinking activity in response to these stimuli (EMG activity, 400% contrast: 42.9%Δ [28.4, 57.4]; blink activity, 400% contrast: 11.2% [8.8, 13.6]) as compared to the MO (EMG activity, 400% contrast: 9.9%Δ [5.8, 14.0]; blink activity, 400% contrast: 4.7% [3.5, 5.9]) and HF control (EMG activity, 400% contrast: 13.2%Δ [7.1, 19.3]; blink activity, 400% contrast: 4.5% [3.1, 5.9]) groups. DISCUSSION Our findings suggest that the intrinsically photosensitive retinal ganglion cells (ipRGCs), which integrate melanopsin and cone signals, provide the afferent input for light-induced reflexive eye closure in a photophobic state. Moreover, we find a dissociation between implicit and explicit measures of interictal photophobia depending on a history of visual aura in migraine. This implies distinct pathophysiology in forms of migraine, interacting with separate neural pathways by which the amplification of ipRGC signals elicits implicit and explicit signs of visual discomfort.
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Affiliation(s)
- Eric A Kaiser
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia.
| | - Harrison McAdams
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
| | - Aleksandra Igdalova
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
| | - Edda B Haggerty
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
| | - Brett L Cucchiara
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
| | - David H Brainard
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
| | - Geoffrey K Aguirre
- From the Departments of Neurology (E.A.K., A.I., E.B.H., B.L.C., G.K.A.) and Neuroscience (H.M.), Perelman School of Medicine, and Department of Psychology (D.H.B.), University of Pennsylvania, Philadelphia
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Abusamak M, Alrawashdeh HM. Post-concussion Syndrome Light Sensitivity: A Case Report and Review of the Literature. Neuroophthalmology 2021; 46:85-90. [DOI: 10.1080/01658107.2021.1983612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Mohammad Abusamak
- Ophthalmology Department, Faculty of Medicine, Al-Balqa Applied University, AlSalt, Jordan
- Department of Ophthalmology, Amman Eye Clinic, Amman, Jordan
| | - Hamzeh Mohammad Alrawashdeh
- Department of Ophthalmology, Amman Eye Clinic, Amman, Jordan
- Department of Ophthalmology, Sharif Eye Centers, Irbid, Jordan
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15
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Wang M, Mason BN, Sowers LP, Kuburas A, Rea BJ, Russo AF. Investigating Migraine-Like Behavior using Light Aversion in Mice. J Vis Exp 2021. [PMID: 34459825 DOI: 10.3791/62839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Migraine is a complex neurological disorder characterized by headache and sensory abnormalities, such as hypersensitivity to light, observed as photophobia. Whilst it is impossible to confirm that a mouse is experiencing migraine, light aversion can be used as a behavioral surrogate for the migraine symptom of photophobia. To test for light aversion, we utilize the light/dark assay to measure the time mice freely choose to spend in either a light or dark environment. The assay has been refined by introducing two critical modifications: pre-exposures to the chamber prior to running the test procedure and adjustable chamber lighting, permitting the use of a range of light intensities from 55 lux to 27,000 lux. Because the choice to spend more time in the dark is also indicative of anxiety, we also utilize a light-independent anxiety test, the open field assay, to distinguish anxiety from light-aversive behavior. Here, we describe a modified test paradigm for the light/dark and open field assays. The application of these assays is described for intraperitoneal injection of calcitonin gene-related peptide (CGRP) in two mouse strains and for optogenetic brain stimulation studies.
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Affiliation(s)
- Mengya Wang
- Department of Neuroscience and Pharmacology, University of Iowa
| | - Bianca N Mason
- School of Behavioral and Brain Sciences, University of Texas at Dallas
| | - Levi P Sowers
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa
| | - Adisa Kuburas
- Department of Molecular Physiology and Biophysics, University of Iowa
| | - Brandon J Rea
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa
| | - Andrew F Russo
- Center for the Prevention and Treatment of Visual Loss, Veterans Administration Health Center, Iowa City, IA; Department of Molecular Physiology and Biophysics, University of Iowa; Department of Neurology, University of Iowa;
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16
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Diel RJ, Mehra D, Kardon R, Buse DC, Moulton E, Galor A. Photophobia: shared pathophysiology underlying dry eye disease, migraine and traumatic brain injury leading to central neuroplasticity of the trigeminothalamic pathway. Br J Ophthalmol 2021; 105:751-760. [PMID: 32703784 PMCID: PMC8022288 DOI: 10.1136/bjophthalmol-2020-316417] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/26/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Photophobia is a potentially debilitating symptom often found in dry eye disease (DE), migraine and traumatic brain injury (TBI). METHODS We conducted a review of the literature via a PubMed search of English language articles with a focus on how photophobia may relate to a shared pathophysiology across DE, migraine and TBI. RESULTS DE, migraine and TBI are common conditions in the general population, are often comorbid, and share photophobia as a symptom. Across the three conditions, neural dysregulation of peripheral and central nervous system components is implicated in photophobia in various animal models and in humans. Enhanced activity of the neuropeptide calcitonin gene-related peptide (CGRP) is closely linked to photophobia. Current therapies for photophobia include glasses which shield the eyes from specific wavelengths, botulinum toxin, and inhibition of CGRP and its receptor. Many individuals have persistent photophobia despite the use of these therapies, and thus, development of new therapies is needed. CONCLUSIONS The presence of photophobia in DE, migraine and TBI suggests shared trigeminothalamic pathophysiologic mechanisms, as explained by central neuroplasticity and hypersensitivity mediated by neuropeptide CGRP. Treatment strategies which target neural pathways (ie, oral neuromodulators, transcutaneous nerve stimulation) should be considered in patients with persistent photophobia, specifically in individuals with DE whose symptoms are not controlled with traditional therapies.
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Affiliation(s)
- Ryan J Diel
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals & Clinics, Iowa City, Iowa, USA
| | - Divy Mehra
- Ophthalmology, VA Medical Center Miami, Miami, Florida, USA
- Ophthalmology, University of Miami Bascom Palmer Eye Institute, Miami, Florida, USA
| | - Randy Kardon
- Department of Ophthalmology and Visual Sciences, University of Iowa Hospitals & Clinics, Iowa City, Iowa, USA
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Health Care System, Iowa City, IA, USA
| | - Dawn C Buse
- Albert Einstein College of Medicine Department of Neurology, Bronx, New York, USA
| | - Eric Moulton
- Department of Anesthesiology, Center for Pain and the Brain; Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, USA
| | - Anat Galor
- Ophthalmology, VA Medical Center Miami, Miami, Florida, USA
- Ophthalmology, University of Miami Bascom Palmer Eye Institute, Miami, Florida, USA
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17
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Baksh BS, Garcia JC, Galor A. Exploring the Link Between Dry Eye and Migraine: From Eye to Brain. Eye Brain 2021; 13:41-57. [PMID: 33692643 PMCID: PMC7939506 DOI: 10.2147/eb.s234073] [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: 12/02/2020] [Accepted: 02/17/2021] [Indexed: 11/23/2022] Open
Abstract
Dry eye and migraine are common diseases with large societal and economic burdens that have recently been associated in the literature. This review outlines the link between dry eye and migraine, which may have implications for reducing their respective burdens. We highlight possible shared pathophysiology, including peripheral and central sensitization, as the potential link between dry eye and migraine. Finally, therapies targeting similar pathophysiological mechanisms between dry eye and migraine are discussed.
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Affiliation(s)
- Brandon S Baksh
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- University of Miami Miller School of Medicine, Miami, FL, USA
| | - Julia Costa Garcia
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Faculdade de Medicina (FMB) da Universidade do Estado de São Paulo (UNESP), Botucatu, Brazil
| | - Anat Galor
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Ophthalmology, Miami Veterans Affairs Medical Center, Miami, FL, USA
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18
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Vit JP, Fuchs DT, Angel A, Levy A, Lamensdorf I, Black KL, Koronyo Y, Koronyo-Hamaoui M. Color and contrast vision in mouse models of aging and Alzheimer's disease using a novel visual-stimuli four-arm maze. Sci Rep 2021; 11:1255. [PMID: 33441984 PMCID: PMC7806734 DOI: 10.1038/s41598-021-80988-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 12/31/2020] [Indexed: 12/14/2022] Open
Abstract
We introduce a novel visual-stimuli four-arm maze (ViS4M) equipped with spectrally- and intensity-controlled LED emitters and dynamic grayscale objects that relies on innate exploratory behavior to assess color and contrast vision in mice. Its application to detect visual impairments during normal aging and over the course of Alzheimer’s disease (AD) is evaluated in wild-type (WT) and transgenic APPSWE/PS1∆E9 murine models of AD (AD+) across an array of irradiance, chromaticity, and contrast conditions. Substantial color and contrast-mode alternation deficits appear in AD+ mice at an age when hippocampal-based memory and learning is still intact. Profiling of timespan, entries and transition patterns between the different arms uncovers variable AD-associated impairments in contrast sensitivity and color discrimination, reminiscent of tritanomalous defects documented in AD patients. Transition deficits are found in aged WT mice in the absence of alternation decline. Overall, ViS4M is a versatile, controlled device to measure color and contrast-related vision in aged and diseased mice.
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Affiliation(s)
- Jean-Philippe Vit
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA.,Biobehavioral Research Core, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Dieu-Trang Fuchs
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Ariel Angel
- Pharmaseed Ltd., 9 Hamazmera St., 74047, Ness Ziona, Israel
| | - Aharon Levy
- Pharmaseed Ltd., 9 Hamazmera St., 74047, Ness Ziona, Israel
| | | | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Yosef Koronyo
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Maya Koronyo-Hamaoui
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, 127 S. San Vicente Blvd., Los Angeles, CA, 90048, USA. .,Department of Neurosurgery, Maxine Dunitz Neurosurgical Research Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
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19
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Díaz NM, Lang RA, Van Gelder RN, Buhr ED. Wounding Induces Facultative Opn5-Dependent Circadian Photoreception in the Murine Cornea. Invest Ophthalmol Vis Sci 2021; 61:37. [PMID: 32543667 PMCID: PMC7415322 DOI: 10.1167/iovs.61.6.37] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Autonomous molecular circadian clocks are present in the majority of mammalian tissues. These clocks are synchronized to phases appropriate for their physiologic role by internal systemic cues, external environmental cues, or both. The circadian clocks of the in vivo mouse cornea synchronize to the phase of the brain's master clock primarily through systemic cues, but ex vivo corneal clocks entrain to environmental light cycles. We evaluated the underlying mechanisms of this difference. Methods Molecular circadian clocks of mouse corneas were evaluated in vivo and ex vivo for response to environmental light. The presence of opsins and effect of genetic deletion of opsins were evaluated for influence on circadian photoresponses. Opn5-expressing cells were identified using Opn5Cre;Ai14 mice and RT-PCR, and they were characterized using immunocytochemistry. Results Molecular circadian clocks of the cornea remain in phase with behavioral circadian locomotor rhythms in vivo but are photoentrainable in tissue culture. After full-thickness incision or epithelial debridement, expression of the opsin photopigment Opn5 is induced in the cornea in a subset of preexisting epithelial cells adjacent to the wound site. This induction coincides with conferral of direct, short-wavelength light sensitivity to the circadian clocks throughout the cornea. Conclusions Corneal circadian rhythms become photosensitive after wounding. Opn5 gene function (but not Opn3 or Opn4 function) is necessary for induced photosensitivity. These results demonstrate that opsin-dependent direct light sensitivity can be facultatively induced in the murine cornea.
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20
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Non-visual Opsins and Novel Photo-Detectors in the Vertebrate Inner Retina Mediate Light Responses Within the Blue Spectrum Region. Cell Mol Neurobiol 2020; 42:59-83. [PMID: 33231827 DOI: 10.1007/s10571-020-00997-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Abstract
In recent decades, a number of novel non-visual opsin photopigments belonging to the family of G protein- coupled receptors, likely involved in a number of non-image-forming processes, have been identified and characterized in cells of the inner retina of vertebrates. It is now known that the vertebrate retina is composed of visual photoreceptor cones and rods responsible for diurnal/color and nocturnal/black and white vision, and cells like the intrinsically photosensitive retinal ganglion cells (ipRGCs) and photosensitive horizontal cells in the inner retina, both detecting blue light and expressing the photopigment melanopsin (Opn4). Remarkably, these non-visual photopigments can continue to operate even in the absence of vision under retinal degeneration. Moreover, inner retinal neurons and Müller glial cells have been shown to express other photopigments such as the photoisomerase retinal G protein-coupled receptor (RGR), encephalopsin (Opn3), and neuropsin (Opn5), all able to detect blue/violet light and implicated in chromophore recycling, retinal clock synchronization, neuron-to-glia communication, and other activities. The discovery of these new photopigments in the inner retina of vertebrates is strong evidence of novel light-regulated activities. This review focuses on the features, localization, photocascade, and putative functions of these novel non-visual opsins in an attempt to shed light on their role in the inner retina of vertebrates and in the physiology of the whole organism.
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21
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Investigation of light-induced lacrimation and pupillary responses in episodic migraine. PLoS One 2020; 15:e0241490. [PMID: 33125423 PMCID: PMC7598498 DOI: 10.1371/journal.pone.0241490] [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: 06/30/2020] [Accepted: 10/15/2020] [Indexed: 12/17/2022] Open
Abstract
The purpose of this pilot study was to investigate the light-induced pupillary and lacrimation responses mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) in migraine. Ten participants with episodic migraine and normal tear production, as well as eleven visually normal controls participated in this study. Following an initial baseline trial (no light flash), participants received seven incremental and alternating red and blue light flashes. Pupillometry recording of the left eye and a 1-min anesthetized Schirmer’s test of the right eye (using 0.5% proparacaine) were performed simultaneously. Intrinsic and extrinsic ipRGC photoactivities did not differ between migraine participants and controls across all intensities and wavelengths. Migraine participants, however, had significantly lower lacrimation than controls following the highest blue intensity. A positive correlation was found between melanopsin-driven post-illumination pupillary responses and lacrimation following blue stimulation in both groups. Our results show that participants with self-reported photophobia have normal ipRGC-driven responses, suggesting that photophobia and pupillary function may be mediated by distinct ipRGC circuits. The positive correlation between melanopsin-driven pupillary responses and light-induced lacrimation suggests the afferent arm of the light-induced lacrimation reflex is melanopsin-mediated and functions normally in migraine. Lastly, the reduced melanopsin-mediated lacrimation at the highest stimulus suggests the efferent arm of the lacrimation reflex is attenuated under certain conditions, which may be a harbinger of dry eye in migraine.
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22
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McAdams H, Kaiser EA, Igdalova A, Haggerty EB, Cucchiara B, Brainard DH, Aguirre GK. Selective amplification of ipRGC signals accounts for interictal photophobia in migraine. Proc Natl Acad Sci U S A 2020; 117:17320-17329. [PMID: 32632006 PMCID: PMC7382295 DOI: 10.1073/pnas.2007402117] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Second only to headache, photophobia is the most debilitating symptom reported by people with migraine. While the melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to play a role, how cone and melanopsin signals are integrated in this pathway to produce visual discomfort is poorly understood. We studied 60 people: 20 without headache and 20 each with interictal photophobia from migraine with or without visual aura. Participants viewed pulses of spectral change that selectively targeted melanopsin, the cones, or both and rated the degree of visual discomfort produced by these stimuli while we recorded pupil responses. We examined the data within a model that describes how cone and melanopsin signals are weighted and combined at the level of the retina and how this combined signal is transformed into a rating of discomfort or pupil response. Our results indicate that people with migraine do not differ from headache-free controls in the manner in which melanopsin and cone signals are combined. Instead, people with migraine demonstrate an enhanced response to integrated ipRGC signals for discomfort. This effect of migraine is selective for ratings of visual discomfort, in that an enhancement of pupil responses was not seen in the migraine group, nor were group differences found in surveys of other behaviors putatively linked to ipRGC function (chronotype, seasonal sensitivity, presence of a photic sneeze reflex). By revealing a dissociation in the amplification of discomfort vs. pupil response, our findings suggest a postretinal alteration in processing of ipRGC signals for photophobia in migraine.
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Affiliation(s)
- Harrison McAdams
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Eric A Kaiser
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Aleksandra Igdalova
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Edda B Haggerty
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Brett Cucchiara
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - David H Brainard
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| | - Geoffrey K Aguirre
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104;
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Hanyuda A, Negishi K, Tsubota K, Ayaki M. Persistently Worsened Tear Break-up Time and Keratitis in Unilateral Pseudophakic Eyes after a Long Postoperative Period. Biomedicines 2020; 8:biomedicines8040077. [PMID: 32260530 PMCID: PMC7235885 DOI: 10.3390/biomedicines8040077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/16/2020] [Accepted: 04/03/2020] [Indexed: 11/16/2022] Open
Abstract
Dry eye disease may develop and persist after cataract surgery; however, unilateral cases have not been fully documented. This cross-sectional, observational study was conducted in five eye clinics in Japan. A total of 1023 outpatients were initially enrolled, and 89 unilateral pseudophakic subjects with 1+ year of follow-up after uncomplicated cataract surgery were included. The tear break-up times (TBUTs) and keratoconjunctival staining results were compared between phakic and pseudophakic eyes. The mean age of the patients was 69.3 ± 10.4 years (32 men, 36.0%), and the mean postoperative period was 4.6 ± 4.4 (1–20) years. For the ophthalmic parameters, the TBUTs were 4.4 ± 1.9 and 3.8 ± 1.9 s (p < 0.001), the keratoconjunctival staining scores were 0.11 ± 0.38 and 0.22 ± 0.56 (p = 0.02), the spherical equivalents were −1.27 ± 2.51 and −0.99 ± 1.45 D (p = 0.21), the astigmatic errors were 0.79 ± 0.66 and 0.78 ± 0.58 D (p = 0.80), and the intraocular pressures were 13.6 ± 2.9 and 13.5 ± 2.6 mmHg (p = 0.62) for the phakic and pseudophakic eyes, respectively. The corneal status was significantly worse in the pseudophakic eyes than in the contralateral phakic eyes, even after more than one year after implant surgery. The present results suggested that long-term ocular surface problems should be examined further since they may not originate only from surgery or postoperative ocular surface diseases.
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Affiliation(s)
- Akiko Hanyuda
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.H.); (K.N.); (K.T.)
- Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo 104-0045, Japan
- Department of Nutrition, Harvard T. H. Chan School of Public Health, Boston, MA 02215, USA
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.H.); (K.N.); (K.T.)
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.H.); (K.N.); (K.T.)
| | - Masahiko Ayaki
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.H.); (K.N.); (K.T.)
- Otake Clinic Moon View Eye Center, Kanagawa 242-0001, Japan
- Correspondence:
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