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Sustar Habjan M, Cvenkel B. Slope between positive and negative ERG components in patients with open-angle glaucoma. Doc Ophthalmol 2024; 149:53-59. [PMID: 38605262 DOI: 10.1007/s10633-024-09972-z] [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: 09/28/2023] [Accepted: 03/21/2024] [Indexed: 04/13/2024]
Abstract
PURPOSE To evaluate ERG morphology, in particular the slope between P50 and N95 components of the PERG, as well as between the b-wave and the photopic negative response (PhNR) of the light-adapted (LA) ERG in patients with retinal ganglion cell (RGC) dysfunction due to open-angle glaucoma. METHODS The PERG and LA-ERG traces of 16 glaucoma patients and 21 age-similar controls were retrospectively analysed. The ERG signal between the peak of the positive component (P50 and b-wave) towards the negative component (N95 and PhNR) was described by a linear regression y = a + bx, where the parameter b indicated the steepness of the P50-N95 and b-PhNR slope. RESULTS The P50-N95 slope was less steep in glaucoma patients (-0.079 ± 0.034 vs. -0.166 ± 0.050 in controls, p < 0.001), while the b-PhNR slope was not affected (-4.2 ± 2.1 vs. -4.4 ± 1.2, p = NS). The P50-N95 slope showed strong correlation with PhNR and N95 amplitude (r = -0.68 and -0.92, respectively; p < 0.001), while the b-PhNR slope correlated only with b-wave amplitude (r = -0.66, p < 0.001). CONCLUSIONS The P50-N95 slope is a sensitive indicator of RGC dysfunction in patients with open-angle glaucoma. A similar component of LA-ERG, the b-PhNR slope, is less affected by glaucomatous RGC dysfunction and probably originates from similar retinal mechanisms as the b-wave.
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Affiliation(s)
- Maja Sustar Habjan
- Department of Ophthalmology, University Medical Centre Ljubljana, Grabloviceva 46, 1000, Ljubljana, Slovenia.
| | - Barbara Cvenkel
- Department of Ophthalmology, University Medical Centre Ljubljana, Grabloviceva 46, 1000, Ljubljana, Slovenia
- Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
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2
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Thompson DA, Bach M, McAnany JJ, Šuštar Habjan M, Viswanathan S, Robson AG. ISCEV standard for clinical pattern electroretinography (2024 update). Doc Ophthalmol 2024; 148:75-85. [PMID: 38488946 PMCID: PMC10954931 DOI: 10.1007/s10633-024-09970-1] [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: 02/14/2024] [Accepted: 02/18/2024] [Indexed: 03/17/2024]
Abstract
The pattern electroretinogram (PERG) is a localized retinal response evoked by a contrast-reversing pattern, usually a black and white checkerboard, which provides information about macular and retinal ganglion cell function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV; www.iscev.org ) presents an updated and revised Standard for clinical PERG testing. This replaces the 2013 and all earlier versions. Minimum protocols for basic PERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis and monitoring purposes, while responding to evolving clinical practices and technology. The main changes in the updated ISCEV Standard for clinical PERG include expanded guidance about large stimulus fields, stimulus parameters for simultaneous PERG and pattern visual evoked potential recording, baseline drift correction, and use of consistent ambient room lighting. These changes aim to provide a clinically relevant document about current practice which will facilitate good quality recordings and inter-laboratory comparisons.
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Affiliation(s)
- D A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Sight and Sound Centre, Great Ormond Street Hospital for Children NHS Trust, London, WC1N 3AJ, UK.
- Great Ormond Street Institute for Child Health, University College London, London, UK.
| | - M Bach
- Eye Center, Medical Center - Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - J J McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - M Šuštar Habjan
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva ulica 46, 1000, Ljubljana, Slovenia
| | - S Viswanathan
- Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, NY, USA
| | - A G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK
- Institute of Ophthalmology, University College London, London, UK
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Jolly JK, Grigg JR, McKendrick AM, Fujinami K, Cideciyan AV, Thompson DA, Matsumoto C, Asaoka R, Johnson C, Dul MW, Artes PH, Robson AG. ISCEV and IPS guideline for the full-field stimulus test (FST). Doc Ophthalmol 2024; 148:3-14. [PMID: 38238632 PMCID: PMC10879267 DOI: 10.1007/s10633-023-09962-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 02/21/2024]
Abstract
The full-field stimulus test (FST) is a psychophysical technique designed for the measurement of visual function in low vision. The method involves the use of a ganzfeld stimulator, as used in routine full-field electroretinography, to deliver full-field flashes of light. This guideline was developed jointly by the International Society for Clinical Electrophysiology of Vision (ISCEV) and Imaging and Perimetry Society (IPS) in order to provide technical information, promote consistency of testing and reporting, and encourage convergence of methods for FST. It is intended to aid practitioners and guide the formulation of FST protocols, with a view to future standardisation.
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Affiliation(s)
- J K Jolly
- Vision and Eye Research Institute, Anglia Ruskin University, Young Street, Cambridge, CB1 2LZ, UK.
| | - J R Grigg
- Save Sight Institute, Specialty of Clinical Ophthalmology and Eye Health, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
- Eye Genetics Research Unit, Sydney Children's Hospitals Network, Save Sight Institute, Children's Medical Research Institute, The University of Sydney, Sydney, NSW, Australia
| | - A M McKendrick
- Lions Eye Institute, University of Western Australia, Perth, Australia
- School of Allied Health, University of Western Australia, Crawley, Australia
| | - K Fujinami
- Laboratory of Visual Physiology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
- Institute of Ophthalmology, University College London, London, UK
| | - A V Cideciyan
- Center for Hereditary Retinal Degenerations, Scheie Eye Institute, University of Pennsylvania, Philadelphia, USA
| | - D A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic, Department of Ophthalmology, Sight and Sound Centre, Great Ormond Street Hospital for Children NHS Trust, London, UK
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - C Matsumoto
- Department of Ophthalmology, Kindai University, Osakasayama, Japan
| | - R Asaoka
- Department of Ophthalmology, Seirei Hamamatsu General Hospital, Hamamatsu, Shizuoka, Japan
- Seirei Christopher University, Hamamatsu, Shizuoka, Japan
- Nanovision Research Division, Research Institute of Electronics, Shizuoka University, Shizuoka, Japan
- The Graduate School for the Creation of New Photonics Industries, Shizuoka, Japan
| | - C Johnson
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, USA
- School of Optometry, The Ohio State University, Columbus, IA, USA
| | - M W Dul
- Department of Biological and Vision Science, College of Optometry, State University of New York, New York, USA
| | - P H Artes
- Faculty of Health, University of Plymouth, Plymouth, UK
| | - A G Robson
- Institute of Ophthalmology, University College London, London, UK
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
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Chen AH, Rafiuddin MSM, Ahmad A, Rosli SA. A simplification of intricate multifocal electroretinogram understanding: A mini-review. Oman J Ophthalmol 2024; 17:11-18. [PMID: 38524335 PMCID: PMC10957048 DOI: 10.4103/ojo.ojo_48_23] [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: 03/08/2023] [Revised: 04/07/2023] [Accepted: 11/26/2023] [Indexed: 03/26/2024] Open
Abstract
Variation of multifocal electroretinogram (mfERG) data presentation in existing scientific publications is a challenge for eye care practitioners to apply the scientific information for evidence-based practice in patient management. This review offers an overview of the mfERG data presentation types. Eight types of data presentation in the form of a table, scatter plot, line graph, bar graph/box plot, single waveform/a group of waveforms, trace array topography, three-dimensional topography, and two-dimensional topography are identified. The table format is used to provide the exact values. Line graphs, scatter, and box plots offer information about the relationship of mfERG values. Waveforms are helpful for comparison between groups or conditions. Topographies outline the retinal, especially the specific localized retinal abnormalities. An infographic of fundamental mfERG electrical response with definitions and clinical indications is provided to bridge the gap between researchers and clinicians to facilitate efficient clinical application.
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Affiliation(s)
- Ai-Hong Chen
- Optometry, iROViS, Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Selangor, Kampus Puncak Alam, Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia
| | | | - Azmir Ahmad
- Optometry, iROViS, Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Selangor, Kampus Puncak Alam, Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia
| | - Saiful Azlan Rosli
- Optometry, iROViS, Faculty of Health Sciences, Universiti Teknologi MARA, Cawangan Selangor, Kampus Puncak Alam, Bandar Puncak Alam, Selangor Darul Ehsan, Malaysia
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5
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Akula JD, Lancos AM, AlWattar BK, De Bruyn H, Hansen RM, Fulton AB. A Simplified Model of Activation and Deactivation of Human Rod Phototransduction-An Electroretinographic Study. Invest Ophthalmol Vis Sci 2023; 64:36. [PMID: 37738060 PMCID: PMC10528468 DOI: 10.1167/iovs.64.12.36] [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: 06/09/2023] [Accepted: 08/28/2023] [Indexed: 09/23/2023] Open
Abstract
Purpose To test the hypothesis that a simple model having properties consistent with activation and deactivation in the rod approximates the whole time course of the photoresponse. Methods Routinely, an exponential of the form f = α·(1 - exp(-(τ·(t - teff)s-1))), with amplitude α, rate constant τ (often scaled by intensity), irreducible delay teff, and time exponent s-1, is fit to the early period of the flash electroretinogram. Notably, s (an integer) represents the three integrating stages in the rod amplification cascade (rhodopsin isomerization, transducin activation, and cGMP hydrolysis). The time course of the photoresponse to a 0.17 cd·s·m-2 conditioning flash (CF) was determined in 21 healthy eyes by presenting the CF plus a bright probe flash (PF) in tandem, separated by interstimulus intervals (ISIs) of 0.01 to 1.4 seconds, and calculating the proportion of the PF a-wave suppressed by the CF at each ISI. To test if similar kinetics describe deactivation, difference of exponential (DoE) functions with common α and teff parameters, respective rate constants for the initiation (I) and quenching (Q) phases of the response, and specified values of s (sI, sQ), were compared to the photoresponse time course. Results As hypothesized, the optimal values of sI and sQ were 3 and 2, respectively. Mean ± SD α was 0.80 ± 0.066, I was 7700 ± 2400 m2·cd-1·s-3, and Q was 1.4 ± 0.47 s-1. Overall, r2 was 0.93. Conclusions A method, including a DoE model with just three free parameters (α, I, Q), that robustly captures the magnitude and time-constants of the complete rod response, was produced. Only two steps integrate to quench the rod photoresponse.
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Affiliation(s)
- James D. Akula
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Annie M. Lancos
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Bilal K. AlWattar
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hanna De Bruyn
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Ronald M. Hansen
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Anne B. Fulton
- Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
- Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
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6
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Mahroo OA. Visual electrophysiology and "the potential of the potentials". Eye (Lond) 2023; 37:2399-2408. [PMID: 36928229 PMCID: PMC10397240 DOI: 10.1038/s41433-023-02491-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 02/09/2023] [Accepted: 03/06/2023] [Indexed: 03/18/2023] Open
Abstract
Visual electrophysiology affords direct, quantitative, objective assessment of visual pathway function at different levels, and thus yields information complementary to, and not necessarily obtainable from, imaging or psychophysical testing. The tests available, and their indications, have evolved, with many advances, both in technology and in our understanding of the neural basis of the waveforms, now facilitating more precise evaluation of physiology and pathophysiology. After summarising the visual pathway and current standard clinical testing methods, this review discusses, non-exhaustively, several developments, focusing particularly on human electroretinogram recordings. These include new devices (portable, non-mydiatric, multimodal), novel testing protocols (including those aiming to separate rod-driven and cone-driven responses, and to monitor retinal adaptation), and developments in methods of analysis, including use of modelling and machine learning. It is likely that several tests will become more accessible and useful in both clinical and research settings. In future, these methods will further aid our understanding of common and rare eye disease, will help in assessing novel therapies, and will potentially yield information relevant to neurological and neuro-psychiatric conditions.
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Affiliation(s)
- Omar A Mahroo
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, UK.
- Retinal and Genetics Services, Moorfields Eye Hospital, 162 City Road, London, UK.
- Section of Ophthalmology and Department of Twin Research and Genetic Epidemiology, King's College London, St Thomas' Hospital Campus, Westminster Bridge Road, London, UK.
- Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, UK.
- Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
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7
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McCulloch DL, Bach M, Brigell M, Chan H, Hamilton R, Hogg C, Odom JV, Robson AG. ISCEV guidelines for calibration and verification of stimuli and recording instruments (2023 update). Doc Ophthalmol 2023:10.1007/s10633-023-09932-z. [PMID: 37269394 DOI: 10.1007/s10633-023-09932-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 03/14/2023] [Indexed: 06/05/2023]
Abstract
This document developed by the International Society for Clinical Electrophysiology of Vision (ISCEV) provides guidance for calibration and verification of stimulus and recording systems specific to clinical electrophysiology of vision. This guideline provides additional information for those using ISCEV Standards and Extended protocols and supersedes earlier Guidelines. The ISCEV guidelines for calibration and verification of stimuli and recording instruments (2023 update) were approved by the ISCEV Board of Directors 01, March 2023.
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Affiliation(s)
- Daphne L McCulloch
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
| | - Michael Bach
- Eye Center, Medical Center - Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Hoover Chan
- Department of Ophthalmology, University of California, San Francisco, USA
- The Smith-Kettlewell Eye Research Institute, San Francisco, USA
| | - Ruth Hamilton
- Department of Clinical Physics and Bioengineering, Royal Hospital for Children, NHS Greater Glasgow and Clyde, Glasgow, UK
- College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Chris Hogg
- Institute of Ophthalmology, University College London, London, UK
| | - J Vernon Odom
- Department of Ophthalmology and Visual Science, West Virginia University, Morgantown, WV, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Anthony G Robson
- Institute of Ophthalmology, University College London, London, UK
- Department of Electrophysiology, Moorfields Eye Hospital, 162 City Road, London, EC1V2PD, UK
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8
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McAnany JJ, Park JC. Rod photoreceptor activation and deactivation in early-stage diabetic eye disease. Doc Ophthalmol 2023:10.1007/s10633-023-09925-y. [PMID: 36763216 DOI: 10.1007/s10633-023-09925-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023]
Abstract
PURPOSE To infer rod phototransduction activation and deactivation characteristics in diabetics who have mild or no clinically-apparent retinopathy. METHODS Fifteen non-diabetic controls, 15 diabetics with no clinically-apparent diabetic retinopathy (NDR), and 15 diabetics with mild non-proliferative diabetic retinopathy (MDR) participated. Dark-adapted flash electroretinograms (3.2 to 4.4 log scot td-s) were recorded to assess rod activation. The a-waves were fit with a Gaussian model to derive Rmp3 (maximum photoreceptor response amplitude) and S (phototransduction sensitivity). Rod deactivation was assessed with a paired flash paradigm, in which a-waves were measured for two flashes separated by inter-stimulus intervals (ISIs) of 0.125 to 16 s. The ISI needed for the a-wave amplitude of the second flash to recover to 50% of the first flash (t50) was determined. The effect of stimulus retinal illuminance on activation and deactivation was evaluated in a subset of control subjects. RESULTS Analysis of variance indicated that both diabetic groups had significant log S reductions compared to controls (p < 0.001). Mean S was reduced by approximately 49% and 78% for the NDR and MDR groups, respectively. In contrast, log Rmp3 and log t50 did not differ significantly among the groups (both p > 0.08). Reducing stimulus retinal illuminance significantly reduced S, but did not significantly affect Rmax or t50. CONCLUSIONS Only phototransduction sensitivity was abnormal in this sample of diabetic subjects. The normal deactivation kinetics suggests that circulating rod current is normal. These findings begin to constrain possible explanations for abnormal rod function in early diabetic retinal disease.
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Affiliation(s)
- J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., MC/648, Chicago, IL, 60612, USA.
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan St., Chicago, IL, 60607, USA.
| | - Jason C Park
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., MC/648, Chicago, IL, 60612, USA
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Pasmanter N, Petersen-Jones SM. Characterization of scotopic and mesopic rod signaling pathways in dogs using the On-Off electroretinogram. BMC Vet Res 2022; 18:422. [PMID: 36463174 PMCID: PMC9719241 DOI: 10.1186/s12917-022-03505-z] [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: 09/18/2021] [Accepted: 11/07/2022] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND The On-Off, or long flash, full field electroretinogram (ERG) separates retinal responses to flash onset and offset. Depending on degree of dark-adaptation and stimulus strength the On and Off ERG can be shaped by rod and cone photoreceptors and postreceptoral cells, including ON and OFF bipolar cells. Interspecies differences have been shown, with predominantly positive Off-response in humans and other primates and a negative Off-response in rodents and dogs. However, the rod signaling pathways that contribute to these differential responses have not been characterized. In this study, we designed a long flash protocol in the dog that varied in background luminance and stimulus strength allowing for some rod components to be present to better characterize how rod pathways vary from scotopic to mesopic conditions. RESULTS With low background light the rod a-wave remains while the b-wave is significantly reduced resulting in a predominantly negative waveform in mesopic conditions. Through modeling and subtraction of the rod-driven response, we show that rod bipolar cells saturate with dimmer backgrounds than rod photoreceptors, resulting in rod hyperpolarization contributing to a large underlying negativity with mesopic backgrounds. CONCLUSIONS Reduction in rod bipolar cell responses in mesopic conditions prior to suppression of rod photoreceptor responses may reflect the changes in signaling pathway of rod-driven responses needed to extend the range of lighting conditions over which the retina functions.
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Affiliation(s)
- Nate Pasmanter
- grid.17088.360000 0001 2150 1785Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D208 East Lansing, MI USA
| | - Simon M. Petersen-Jones
- grid.17088.360000 0001 2150 1785Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D208 East Lansing, MI USA
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10
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Formation of the pediatric electroretinogram database parameters for the development of doctor’s decisionmaking algorithm. ACTA BIOMEDICA SCIENTIFICA 2022. [DOI: 10.29413/abs.2022-7.2.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electroretinography is a non-invasive electrophysiological method standardized by the International Society for Clinical Electrophysiology of Vision (ISCEV). Electroretinography has been used for the clinical application and standardization of electrophysiological protocols for diagnosing the retina since 1989. Electroretinography become fundamental ophthalmological research method that may assesses the state of the retina. To transfer clinical practice to patients the establishment of standardized protocols is an important step. It is important for monitoring successful molecular therapy in retinal degeneration. Retinitis pigmentosa or achromatopsia and, consequently, affected cones or rods photoreceptors is corresponded to complete absent of electrical response. Thus, detection of even modest improvements after therapeutic treatment is required. Standardized protocols allow the implementation of electroretinography under conditions of optimization of sensitivity and specificity during clinical trials. It should be noted that the literature on retinal diseases demonstrates clinical cases in which patients may have several retinal diseases at the same time. In such cases, it is necessary to detect a group of characteristics of electrophysiological signals with high accuracy to improve the application of various diagnostic solutions. The classification of electroretinogram signals depends on the quality of labeled biomedical information or databases, in addition to this, the accuracy of the classification results obtained depends not only on computer technology, but also on the quality of the input data. To date, the analysis of electroretinogram signals is realized manually and largely depends on the experience of clinicians. The development of automated algorithms for analyzing electroretinogram signals may simplify routine processes and improve the quality of diagnosing eye diseases. This article describes the formation of the parameters of pediatric electroretinogram database parameters for the development of doctor’s decision-making algorithm. The signal parameters were obtained by extracting the parameters from the wavelet scalogram of the electroretinogram signal using digital image processing and machine learning methods.
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Robson AG, Frishman LJ, Grigg J, Hamilton R, Jeffrey BG, Kondo M, Li S, McCulloch DL. ISCEV Standard for full-field clinical electroretinography (2022 update). Doc Ophthalmol 2022; 144:165-177. [PMID: 35511377 PMCID: PMC9192408 DOI: 10.1007/s10633-022-09872-0] [Citation(s) in RCA: 200] [Impact Index Per Article: 100.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 03/14/2022] [Indexed: 11/26/2022]
Abstract
The full-field electroretinogram (ERG) is a mass electrophysiological response to diffuse flashes of light and is used widely to assess generalized retinal function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV Standard for clinical ERG testing. Minimum protocols for basic ERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis, monitoring and inter-laboratory comparisons, while also responding to evolving clinical practices and technology. The main changes in this updated ISCEV Standard for clinical ERGs include specifying that ERGs may meet the Standard without mydriasis, providing stimuli adequately compensate for non-dilated pupils. There is more detail about analysis of dark-adapted oscillatory potentials (OPs) and the document format has been updated and supplementary content reduced. There is a more detailed review of the origins of the major ERG components. Several tests previously tabulated as additional ERG protocols are now cited as published ISCEV extended protocols. A non-standard abbreviated ERG protocol is described, for use when patient age, compliance or other circumstances preclude ISCEV Standard ERG testing.
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Affiliation(s)
- Anthony G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, 162 City Road, London, EC1V2PD, UK.
- Institute of Ophthalmology, University College London, London, UK.
| | | | - John Grigg
- Save Sight Institute Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Ruth Hamilton
- Department of Clinical Physics and Bioengineering, Royal Hospital for Children, NHS Greater Glasgow and Clyde, Glasgow, UK
- College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Brett G Jeffrey
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-1860, USA
| | - Mineo Kondo
- Mie University Graduate School of Medicine, Tsu, Japan
| | - Shiying Li
- Department of Ophthalmology, Xiang'an Hospital of Xiamen University, Fujian, China
- Eye Institute of Xiamen University (EIXU), Fujian, China
| | - Daphne L McCulloch
- School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
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12
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Pasmanter N, Occelli LM, Komáromy AM, Petersen-Jones SM. Use of extended protocols with nonstandard stimuli to characterize rod and cone contributions to the canine electroretinogram. Doc Ophthalmol 2022; 144:81-97. [PMID: 35247111 PMCID: PMC10426558 DOI: 10.1007/s10633-022-09866-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 02/08/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE In this study, we assessed several extended electroretinographic protocols using nonstandard stimuli. Our aim was to separate and quantify the contributions of different populations of retinal cells to the overall response, both to assess normal function and characterize dogs with inherited retinal disease. METHODS We investigated three different protocols for measuring the full-field flash electroretinogram-(1) chromatic dark-adapted red and blue flashes, (2) increasing luminance blue-background, (3) flicker with fixed frequency and increasing luminance, and flicker with increasing frequency at a fixed luminance-to assess rod and cone contributions to electroretinograms recorded in phenotypically normal control dogs and dogs lacking rod function. RESULTS Temporal separation of the rod- and cone-driven responses is possible in the fully dark-adapted eye using dim red flashes. A- and b-wave amplitudes decrease at different rates with increasing background luminance in control dogs. Flicker responses elicited with extended flicker protocols are well fit with mathematical models in control dogs. Dogs lacking rod function demonstrated larger amplitude dark-adapted compared to light-adapted flicker responses. CONCLUSIONS Using extended protocols of the full-field electroretinogram provides additional characterization of the health and function of different populations of cells in the normal retina and enables quantifiable comparison between phenotypically normal dogs and those with retinal disease.
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Affiliation(s)
- Nate Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI, 48824, USA.
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Simunovic MP, Grigg J, Mahroo O. Vision at the limits: absolute threshold, visual function, and outcomes in clinical trials. Surv Ophthalmol 2022; 67:1270-1286. [DOI: 10.1016/j.survophthal.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/20/2022] [Accepted: 01/24/2022] [Indexed: 11/30/2022]
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Clinical electrophysiology of vision-commentary on current status and future prospects. Eye (Lond) 2021; 35:2341-2343. [PMID: 34045684 PMCID: PMC8376889 DOI: 10.1038/s41433-021-01592-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/17/2021] [Accepted: 04/30/2021] [Indexed: 11/25/2022] Open
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ERG assessment of altered retinal function in canine models of retinitis pigmentosa and monitoring of response to translatable gene augmentation therapy. Doc Ophthalmol 2021; 143:171-184. [PMID: 33818677 DOI: 10.1007/s10633-021-09832-0] [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: 06/13/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To analyze ERG responses from two dog models of retinitis pigmentosa, one due to a PDE6A mutation and the other a CNGB1 mutation, both to assess the effect of these mutations on retinal function and the ability of gene augmentation therapy to restore normal function. METHODS Scotopic and photopic ERGs from young affected and normal control dogs and affected dogs following AAV-mediated gene augmentation therapy were analyzed. Parameters reflecting rod and cone function were collected by modeling the descending slope of the a-wave to measure receptor response and sensitivity. Rod-driven responses were further assessed by Naka-Rushton fitting of the first limb of the scotopic b-wave luminance-response plot. RESULTS PDE6A-/- dogs showed a dramatic decrease in rod-driven responses with very reduced rod maximal responses and sensitivity. There was a minor reduction in the amplitude of maximal cone responses. In contrast, CNGB1-/- dogs had some residual rod responses with reduced amplitude and sensitivity and normal cone responses. Following gene augmentation therapy, rod parameters were substantially improved in both models with restoration of sensitivity parameters log S and log K and a large increase in log Rmax in keeping with rescue of normal rod phototransduction in the treated retinal regions. CONCLUSIONS Modeling of rod and cone a-waves and the luminance-response function of the scotopic b-wave characterized the loss of rod photoreceptor function in two dog models of retinitis pigmentosa and showed the effectiveness of gene augmentation therapy in restoring normal functional parameters.
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ISCEV standard for clinical multifocal electroretinography (mfERG) (2021 update). Doc Ophthalmol 2021; 142:5-16. [PMID: 33492495 PMCID: PMC7906932 DOI: 10.1007/s10633-020-09812-w] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 11/15/2022]
Abstract
The multifocal electroretinogram (mfERG) is an electrophysiological test that allows the function of multiple discrete areas of the retina to be tested simultaneously. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV standard for clinical mfERG and defines minimum protocols for basic clinical mfERG recording and reporting so that responses can be recognized and compared from different laboratories worldwide. The major changes compared with the previous mfERG standard relate to the minimum length of m-sequences used for recording, reporting of results and a change in document format, to be more consistent with other ISCEV standards.
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Hu S, Anastassov IA, Kreitzer MA, Slaughter MM, Chappell RL. A dark decrement for enhanced dynamic sensitivity of retinal photoreceptors. Vision Res 2020; 180:80-86. [PMID: 33387934 DOI: 10.1016/j.visres.2020.12.005] [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: 07/20/2020] [Revised: 11/06/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
The skate retina provides a native all-rod retina suited for investigating a single type of photoreceptor regarding its properties and signaling to second order cells. Using the aspartate-induced isolated A-wave of the skate eyecup electroretinogram (ERG), it has been shown that adaptation in rods remains Weber-Fechner-like over a 6-log unit increase in background light intensity. Zinc, which can block calcium channels, has been found in the rod synaptic terminal and the synaptic cleft. Histidine is a zinc chelator. Voltage signals from neurons post-synaptic to rods indicate that histidine increases the dark release of glutamate and increases the horizontal cell light response. In histidine, the A-wave response to various light intensities in the dark-adapted retina increased more than fifty percent, corresponding to the effect on horizontal cells. In the presence of background light, although histidine-treated rod light responses remained Weber-Fechner-like, their increment threshold was raised significantly. This indicates that endogenous zinc feedback serves to increase rod sensitivity in a light-adapted retina, despite a corresponding reduction of threshold sensitivity in the dark. We propose that the increase in A-wave amplitude is a result of the increased conductance at the synaptic terminal and that the A-wave can be used to monitor changes in rod transmitter release. Furthermore, endogenous zinc may also provide the benefit of reducing metabolic stress and the risk of glutamate toxicity in the dark.
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Affiliation(s)
- Shen Hu
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Ivan A Anastassov
- Department of Biology, San Francisco State University, San Francisco, CA, United States; Marine Biological Laboratory, Woods Hole, MA, United States
| | - Matthew A Kreitzer
- Marine Biological Laboratory, Woods Hole, MA, United States; Department of Biology, Indiana Wesleyan University, Marion, IN, United States
| | - Malcolm M Slaughter
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Richard L Chappell
- Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, United States; Marine Biological Laboratory, Woods Hole, MA, United States.
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