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Arévalo-López C, Gleitze S, Madariaga S, Plaza-Rosales I. Pupillary response to chromatic light stimuli as a possible biomarker at the early stage of glaucoma: a review. Int Ophthalmol 2023; 43:343-356. [PMID: 35781599 DOI: 10.1007/s10792-022-02381-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 06/14/2022] [Indexed: 02/07/2023]
Abstract
Glaucoma is a multifactorial neurodegenerative disease of the optic nerve currently considered a severe health problem because of its high prevalence, being the primary cause of irreversible blindness worldwide. The most common type corresponds to Primary Open-Angle Glaucoma. Glaucoma produces, among other alterations, a progressive loss of retinal ganglion cells (RGC) and its axons which are the key contributors to generate action potentials that reach the visual cortex to create the visual image. Glaucoma is characterized by Visual Field loss whose main feature is to be painless and therefore makes early detection difficult, causing a late diagnosis and a delayed treatment indication that slows down its progression. Intrinsically photosensitive retinal ganglion cells, which represent a subgroup of RGCs are characterized by their response to short-wave light stimulation close to 480 nm, their non-visual function, and their role in the generation of the pupillary reflex. Currently, the sensitivity of clinical examinations correlates to RGC damage; however, the need for an early damage biomarker is still relevant. It is an urgent task to create new diagnostic approaches to detect an early stage of glaucoma in a prompt, quick, and economical manner. We summarize the pathology of glaucoma and its current clinical detection methods, and we suggest evaluating the pupillary response to chromatic light as a potential biomarker of disease, due to its diagnostic benefit and its cost-effectiveness in clinical practice in order to reduce irreversible damage caused by glaucoma.
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Affiliation(s)
- Carla Arévalo-López
- Department of Medical Technology, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Silvia Gleitze
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Samuel Madariaga
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Laboratorio de Neurosistemas, Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Ecological Cognitive Neuroscience Group, Santiago, Chile
| | - Iván Plaza-Rosales
- Department of Medical Technology, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Laboratorio de Neurosistemas, Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago, Chile. .,Ecological Cognitive Neuroscience Group, Santiago, Chile.
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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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Rukmini AV, Chew MC, Finkelstein MT, Atalay E, Baskaran M, Nongpiur ME, Gooley JJ, Aung T, Milea D, Najjar RP. Effects of low and moderate refractive errors on chromatic pupillometry. Sci Rep 2019; 9:4945. [PMID: 30894608 PMCID: PMC6426861 DOI: 10.1038/s41598-019-41296-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 03/04/2019] [Indexed: 11/16/2022] Open
Abstract
Chromatic pupillometry is an emerging modality in the assessment of retinal and optic nerve disorders. Herein, we evaluate the effect of low and moderate refractive errors on pupillary responses to blue- and red-light stimuli in a healthy older population. This study included 139 participants (≥50 years) grouped by refractive error: moderate myopes (>−6.0D and ≤−3.0D, n = 24), low myopes (>−3.0D and <−0.5D, n = 30), emmetropes (≥−0.5D and ≤0.5D, n = 31) and hyperopes (>0.5D and <6.0D, n = 54). Participants were exposed to logarithmically ramping-up blue (462 nm) and red (638 nm) light stimuli, designed to sequentially activate rods, cones and intrinsically-photosensitive retinal ganglion cells. Pupil size was assessed monocularly using infra-red pupillography. Baseline pupil diameter correlated inversely with spherical equivalent (R = −0.26, P < 0.01), and positively with axial length (R = 0.37, P < 0.01) and anterior chamber depth (R = 0.43, P < 0.01). Baseline-adjusted pupillary constriction amplitudes to blue light did not differ between groups (P = 0.45), while constriction amplitudes to red light were greater in hyperopes compared to emmetropes (P = 0.04) at moderate to bright light intensities (12.25–14.0 Log photons/cm²/s). Our results demonstrate that low and moderate myopia do not alter pupillary responses to ramping-up blue- and red-light stimuli in healthy older individuals. Conversely, pupillary responses to red light should be interpreted cautiously in hyperopic eyes.
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Affiliation(s)
- A V Rukmini
- Singapore Eye Research Institute, Singapore, Singapore
| | | | | | - Eray Atalay
- Singapore Eye Research Institute, Singapore, Singapore.,Eskisehir Osmangazi University, Faculty of Medicine, Eskisehir, Turkey
| | - Mani Baskaran
- Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,The Ophthalmology & Visual Sciences ACP (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore
| | - Monisha E Nongpiur
- Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,The Ophthalmology & Visual Sciences ACP (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore
| | - Joshua J Gooley
- Centre for Cognitive Neuroscience, Programme in Neuroscience and Behavioural Disorders, Duke-NUS Medical School, Singapore, Singapore
| | - Tin Aung
- Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,The Ophthalmology & Visual Sciences ACP (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Dan Milea
- Singapore Eye Research Institute, Singapore, Singapore.,Singapore National Eye Centre, Singapore, Singapore.,The Ophthalmology & Visual Sciences ACP (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore
| | - Raymond P Najjar
- Singapore Eye Research Institute, Singapore, Singapore. .,The Ophthalmology & Visual Sciences ACP (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore.
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Rukmini AV, Milea D, Gooley JJ. Chromatic Pupillometry Methods for Assessing Photoreceptor Health in Retinal and Optic Nerve Diseases. Front Neurol 2019; 10:76. [PMID: 30809186 PMCID: PMC6379484 DOI: 10.3389/fneur.2019.00076] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/21/2019] [Indexed: 12/19/2022] Open
Abstract
The pupillary light reflex is mediated by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs), which also receive input from rods and cones. Melanopsin-dependent pupillary light responses are short-wavelength sensitive, have a higher threshold of activation, and are much slower to activate and de-activate compared with rod/cone-mediated responses. Given that rod/cone photoreceptors and melanopsin differ in their response properties, light stimuli can be designed to stimulate preferentially each of the different photoreceptor types, providing a read-out of their function. This has given rise to chromatic pupillometry methods that aim to assess the health of outer retinal photoreceptors and ipRGCs by measuring pupillary responses to blue or red light stimuli. Here, we review different types of chromatic pupillometry protocols that have been tested in patients with retinal or optic nerve disease, including approaches that use short-duration light exposures or continuous exposure to light. Across different protocols, patients with outer retinal disease (e.g., retinitis pigmentosa or Leber congenital amaurosis) show reduced or absent pupillary responses to dim blue-light stimuli used to assess rod function, and reduced responses to moderately-bright red-light stimuli used to assess cone function. By comparison, patients with optic nerve disease (e.g., glaucoma or ischemic optic neuropathy, but not mitochondrial disease) show impaired pupillary responses during continuous exposure to bright blue-light stimuli, and a reduced post-illumination pupillary response after light offset, used to assess melanopsin function. These proof-of-concept studies demonstrate that chromatic pupillometry methods can be used to assess damage to rod/cone photoreceptors and ipRGCs. In future studies, it will be important to determine whether chromatic pupillometry methods can be used for screening and early detection of retinal and optic nerve diseases. Such methods may also prove useful for objectively evaluating the degree of recovery to ipRGC function in blind patients who undergo gene therapy or other treatments to restore vision.
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Affiliation(s)
- A V Rukmini
- Programme in Neuroscience and Behavioural Disorders, Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, Singapore
| | - Dan Milea
- Singapore National Eye Centre, Singapore Eye Research Institute, Singapore, Singapore.,The Ophthalmology and Visual Sciences Academic Clinical Programme (EYE-ACP), SingHealth and Duke-NUS, Singapore, Singapore
| | - Joshua J Gooley
- Programme in Neuroscience and Behavioural Disorders, Centre for Cognitive Neuroscience, Duke-NUS Medical School, Singapore, Singapore
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