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Dunn M, Cull G, Reynaud J, Jennings D, Holthausen T, Di Polo A, Fortune B. Utility of Light-Adapted Full-Field Electroretinogram ON and OFF Responses for Detecting Glaucomatous Functional Damage. Transl Vis Sci Technol 2023; 12:16. [PMID: 37594448 PMCID: PMC10445177 DOI: 10.1167/tvst.12.8.16] [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: 12/19/2022] [Accepted: 07/13/2023] [Indexed: 08/19/2023] Open
Abstract
Purpose To compare parameters of electroretinogram (ERG) responses for their ability to detect functional loss in early stages of nonhuman primate (NHP) experimental glaucoma (EG), including photopic negative responses (PhNR) to a standard brief red flash on a blue background (R/B) and 200-ms-long R/B and white-on-white (W/W) flashes, to W/W flicker stimuli (5-50 Hz), and to a dark-adapted intensity series. Methods Light-adapted ERGs were recorded in 12 anesthetized monkeys with unilateral EG. Amplitudes and implicit times of the a-wave, b-wave, and d-wave were measured, as well as amplitudes of PhNRs and oscillatory potentials for flash onset and offset. Flicker ERGs were measured using peak-trough and fundamental frequency analyses. Dark-adapted ERG parameters were modeled by Naka-Rushton relationships. Results Only PhNR amplitudes were significantly reduced in EG eyes compared to fellow control (FC) eyes. The d-wave implicit time was delayed in EG versus FC eyes only for the W/W long flash, but in all eyes it was 10 to 20 ms slower for R/B versus the W/W condition. Flicker ERGs were <0.5 ms delayed in EG versus FC overall, but amplitudes were affected only at 5 Hz. The brief R/B PhNR amplitude had the highest sensitivity to detect EG and strongest correlation to parameters of structural damage. Conclusions The PhNR to the standard brief R/B stimulus was best for detecting and following early-stage functional loss in NHP EG. Translational Relevance These results suggest that there would be no benefit in using longer duration flashes to separate onset and offset responses for clinical management of glaucoma.
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Affiliation(s)
- Michaela Dunn
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
| | - Grant Cull
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
| | - Juan Reynaud
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
| | - Dawn Jennings
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
| | - Trinity Holthausen
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, Montréal, QC, Canada
- Neuroscience Division, Centre de Recherche du Centre Hospitalier, Université de Montréal, Montréal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute, Legacy Health, Portland, OR, USA
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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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Relationship between stimulus size and different components of the electroretinogram (ERG) elicited by flashed stimuli. Doc Ophthalmol 2020; 142:213-231. [PMID: 33063285 DOI: 10.1007/s10633-020-09797-6] [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: 04/21/2020] [Accepted: 10/01/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate how light stimulus conditions of varying spatial sizes affect components of the flash and long-flash electroretinogram (ERG) in normal subjects. METHOD Three stimulus conditions were generated by a Ganzfeld stimulator: a white flash on white background (WoW), a red flash on a blue background (RoB) and an L+M-cone isolating on-off (long flash) stimulus (Cone Iso). ERGs were recorded from six subjects (5 M, 1 F) with DTL electrodes to full-field (FF), 70°, 60°, 50°, 40°, 30° and 20° diameter circular stimuli. Amplitudes and peak times for a-, b-, d- and i-wave, and PhNR were examined. PhNR amplitudes were estimated in two different ways: from baseline (fB) and from preceding b-wave peak (fP). RESULTS With decreasing stimulus size, amplitudes for all ERG waveform components attenuated and peak times increased, although the effect varied across different components. An exponential fit described the relationship between amplitudes and size of stimulated retinal area well for most components and conditions (R2= 0.75-0.99), except for PhNR(fB) (R2= - 0.16-0.88). For peak times, an exponential decay function also fitted the data well (R2= 0.81-0.97), except in a few cases where the exponential constant was too small and a linear regression function was applied instead (a-wave Cone Iso, b- and i-wave WoW). The exponential constants for RoB amplitudes (b-wave, PhNR(fB), PhNR(fP)) were larger compared to their counterparts under WoW (p < 0.05), while there was no difference between the constants for a-wave amplitudes and peak times and for PhNR peak times. The exponential constants of amplitudes vs. area under WoW and Cone Iso were remarkably similar, while under RoB PhNR(fB) showed larger constants compared to either a- or b-wave (p < 0.05). CONCLUSION ERG components change in a predictable way with stimulus size and spectral characteristics of the stimulus under these conditions. This predictability could allow a modified version of these sets of stimuli to be tested for clinical applicability.
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4
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Developments in non-invasive visual electrophysiology. Vision Res 2020; 174:50-56. [PMID: 32540518 DOI: 10.1016/j.visres.2020.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 01/23/2023]
Abstract
To study the physiology of the primate visual system, non-invasive electrophysiological techniques are of major importance. Two main techniques are available: the electroretinogram (ERG), a mass potential originating in the retina, and the visual evoked potential (VEP), which reflects activity in the primary visual cortex. In this overview, the history and the state of the art of these techniques are briefly presented as an introduction to the special issue "New Developments in non-invasive visual electrophysiology". The overview and the special issue can be used as the starting point for exciting new developments in the electrophysiology of primate and mammalian vision.
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Barboni MTS, Hauzman E, Nagy BV, Martins CMG, Aher AJ, Tsai TI, Bonci DMO, Ventura DF, Kremers J. Electrodiagnosis of dichromacy. Vision Res 2019; 158:135-145. [PMID: 30844384 DOI: 10.1016/j.visres.2019.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 11/26/2022]
Abstract
Retinal and cortical signals initiated by a single cone type can be recorded using the spectral compensation (or silent substitution) paradigm. Moreover, responses to instantaneous excitation increments combined with gradual excitation decreases are dominated by the response to the excitation increment. Similarly, the response to a sudden excitation decrement dominates the overall response when combined with a gradual excitation increase. Here ERGs and VEPs were recorded from 34 volunteers [25.9 ± 10.4 years old (mean ± 1 SD); 25 males, 9 females] to sawtooth flicker (4 Hz) stimuli that elicited L- or M-cone responses using triple silent substitution. The mean luminance (284 cd/m2) and the mean chromaticity (x = 0.5686, y = 0.3716; CIE 1931 color space) remained constant and thus the state of adaptation was the same in all conditions. Color discrimination thresholds along protan, deutan, and tritan axes were obtained from all participants. Dichromatic subjects were genetically characterized by molecular analysis of their opsin genes. ERG responses to L-cone stimuli were absent in protanopes whereas ERG responses to M-cone stimuli were strongly reduced in deuteranopes. Dichromats showed generally reduced VEP amplitudes. Responses to cone-specific stimuli obtained with standard electrophysiological methods may give the same classification as that obtained with the Cambridge Colour Test and in some cases with the genetic analysis of the L- and M-opsin genes. Therefore, cone-specific ERGs and VEPs may be reliable methods to detect cone dysfunction. The present data confirm and emphasize the potential use of cone-specific stimulation, combined with standard visual electrodiagnostic protocols.
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Affiliation(s)
- Mirella Telles Salgueiro Barboni
- Department of Experimental Psychology, University of Sao Paulo, Brazil; Department of Ophthalmology, Semmelweis University, Budapest, Hungary.
| | - Einat Hauzman
- Department of Experimental Psychology, University of Sao Paulo, Brazil; Instituto Israelita de Ensino e Pesquisa Albert Einstein, Sao Paulo, Brazil
| | - Balázs Vince Nagy
- Department of Experimental Psychology, University of Sao Paulo, Brazil; Department of Mechatronics, Optics and Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
| | | | - Avinash J Aher
- Department of Ophthalmology, University Hospital, Erlangen, Germany
| | - Tina I Tsai
- Department of Ophthalmology, University Hospital, Erlangen, Germany
| | - Daniela Maria Oliveria Bonci
- Department of Experimental Psychology, University of Sao Paulo, Brazil; Instituto Israelita de Ensino e Pesquisa Albert Einstein, Sao Paulo, Brazil
| | - Dora Fix Ventura
- Department of Experimental Psychology, University of Sao Paulo, Brazil; Instituto Israelita de Ensino e Pesquisa Albert Einstein, Sao Paulo, Brazil
| | - Jan Kremers
- Department of Ophthalmology, University Hospital, Erlangen, Germany; Department of Biology, Animal Physiology, FAU Erlangen-Nürnberg, Erlangen, Germany
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Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum procedure, but encourages more extensive testing. This ISCEV extended protocol describes an extension to the ERG standard, namely the photopic On-Off ERG, and outlines common clinical applications. A light stimulus duration of 150-200 ms is used in the presence of a rod-suppressing background to elicit cone-driven On- and Off-system ERG components. The On-response occurs after the stimulus onset and has a negative a-wave and positive b-wave. The Off d-wave is a positive component evoked by stimulus offset. Common diagnoses that may benefit from additional photopic On-Off ERG testing include retinal dystrophies and retinal disorders that cause dysfunction at a level that is post-phototransduction or post-receptoral. On-Off ERGs assess the relative involvement of On- and Off-systems and may be of use in the diagnosis of disorders such as complete and incomplete congenital stationary night blindness (complete and incomplete CSNB), melanoma-associated retinopathy, and some forms of autoimmune retinopathy. The photopic On-Off ERGs may also be useful in X-linked retinoschisis, Batten disease, Duchenne muscular dystrophy, spinocerebellar degeneration, quinine toxicity, and other retinal disorders.
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Abstract
Electroretinography is a crucial assay for studying the function and the functional integrity of the retina. The mouse is an important animal model for studying the retinal neurons and circuitries. In addition, it is often used as animal model for human retinal disorders. Therefore, a good understanding of the procedures in animal handling, of the methods for data analysis and of the requirements for stimulators and for the data acquisition equipment is of importance. Here, the currently most common methods and materials for in vivo electroretinography in the mouse are discussed.
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Affiliation(s)
- Jan Kremers
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany.
| | - Naoyuki Tanimoto
- Department of Ophthalmology, University Hospital Schleswig-Holstein, Kiel, Germany
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Gauvin M, Sustar M, Little JM, Brecelj J, Lina JM, Lachapelle P. Quantifying the ON and OFF Contributions to the Flash ERG with the Discrete Wavelet Transform. Transl Vis Sci Technol 2017; 6:3. [PMID: 28097047 PMCID: PMC5235331 DOI: 10.1167/tvst.6.1.3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 10/28/2016] [Indexed: 11/24/2022] Open
Abstract
Purpose Discrete wavelet transform (DWT) analyses suggest that the 20- and 40-Hz components of the short-flash photopic electroretinogram (ERG) are closely related to the ON and OFF pathways, respectively. With the DWT, we examined how the ERG ON and OFF components are modulated by the stimulus intensity and/or duration. Methods Discrete wavelet transform descriptors (20, 40 Hz and 40:20-Hz ratio) were extracted from ERGs evoked to 25 combinations of flash durations (150–5 ms) and strengths (0.8–2.8 log cd.m−2). Results In ERGs evoked to the 150-ms stimulus (to separate the ON and OFF ERGs), the 40:20-Hz ratio of ON ERGs (mean ± SD: 0.49 ± 0.04) was significantly smaller (P < 0.05) than that of OFF ERGs (1.71 ± 0.18) owing to a significantly (P < 0.05) higher contribution of the 20 and 40 Hz components to the ON and OFF ERGs, respectively. With brighter stimuli, the ON and OFF components increased similarly (P < 0.05). While progressively shorter flashes had no impact (P > 0.05) on the ON component, it exponentially enhanced (P < 0.05) the OFF component. Conclusions Discrete wavelet transform allows for an accurate determination of ON and OFF retinal pathways even in ERGs evoked to a short flash. To our knowledge, the significant OFF facilitatory effect evidenced with shorter stimuli has not previously been reported. Translational Relevance The DWT approach should offer a rapid, easy, and reproducible approach to retrospectively and prospectively evaluate the function of the retinal ON and OFF pathways using the standard (short-flash duration) clinical ERG stimulus.
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Affiliation(s)
- Mathieu Gauvin
- Department of Ophthalmology & Neurology-Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, Quebec, Canada
| | - Maja Sustar
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - John M Little
- Department of Ophthalmology & Neurology-Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, Quebec, Canada
| | - Jelka Brecelj
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Jean-Marc Lina
- Département de Génie Électrique, École de Technologie Supérieure, Montréal, Québec, Canada ; Centre de Recherches Mathématiques, Montréal, Québec, Canada
| | - Pierre Lachapelle
- Department of Ophthalmology & Neurology-Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, Quebec, Canada
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Tsai TI, Jacob MM, McKeefry D, Murray IJ, Parry NRA, Kremers J. Spatial properties of L- and M-cone driven incremental (On-) and decremental (Off-) electroretinograms: evidence for the involvement of multiple post-receptoral mechanisms. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2016; 33:A1-A11. [PMID: 26974913 DOI: 10.1364/josaa.33.0000a1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
An overview of electroretinogram response components to incremental and decremental steps in L- and M-cone excitation was obtained in human observers, while varying the spatial properties of the stimulus. Responses to L- and M-cone stimuli of opposite polarity resembled each other, particularly within the central 35° of the retina. All amplitudes grew as stimulus size increased; however, earlier and later components of the On- and Off-responses showed differing degrees of dependency on stimulus size. Thus, they may reflect different proportions of responses originating in parvocellular (less stimulus size-dependent) and magnocellular (more stimulus size-dependent) streams.
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Vukmanic E, Godwin K, Shi P, Hughes A, DeMarco P. Full-field electroretinogram response to increment and decrement stimuli. Doc Ophthalmol 2014; 129:85-95. [PMID: 25074040 DOI: 10.1007/s10633-014-9455-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 07/16/2014] [Indexed: 11/24/2022]
Abstract
PURPOSE The d-wave is typically elicited after the termination of an increment flash, but a decrement flash provides an alternative, and perhaps more appropriate, stimulus to elicit the d-wave. Here, we investigated the affects of stimulus polarity on the electroretinogram (ERG) response. METHODS ERG responses elicited to increment and decrement flashes of varying intensity and duration from different background levels were measured from human participants to assess the b-wave and d-wave responses as a function of adaptation level and flash polarity. Response amplitudes were measured using standard metrics for waveform analysis. RESULTS The amplitude of the b-wave is larger than the d-wave regardless of flash polarity when using different background levels which maximized the dynamic range of the two waveforms. However, when response amplitudes are measured from a common background, the d-wave elicited with decrement flash was larger than the b-wave elicited by an increment flash. This trend was evident across a range of background levels. The b-wave and d-wave become separate entities when flash duration reaches approximately 50 ms. Rapid-on and rapid-off sawtooth stimuli were also tested against increment and decrement step stimuli that were matched in mean luminance. These two stimulus types produced different amplitude b-wave and d-wave responses, suggesting asymmetric effects of the two stimulus types on the retinal response. CONCLUSIONS We conclude that the response properties of the b-wave and d-wave are influenced by the duration, polarity and waveform of the stimulus, as well as the background from which the stimuli arise.
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Affiliation(s)
- Eric Vukmanic
- Department of Psychological and Brain Sciences, 317 Life Sciences Bldg., University of Louisville, Louisville, KY, USA
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Abstract
PURPOSE To review three inherited retinal disorders associated with diagnostic or pathognomonic electroretinogram (ERG) abnormalities: cone dystrophy with supernormal rod ERG (KCNV2), enhanced S-cone syndrome (NR2E3), and bradyopsia (RGS9/R9AP). METHODS A review of clinical details, genetic basis, and electrophysiological features in these disorders and a brief summary of the standard and nonstandard ERG techniques required to identify the disorders. RESULTS The electrophysiological features in each of these three disorders are pathognomonic such that the responsible gene can be specified. The results from nonstandard electrophysiological testing in excess of international standards are necessary to describe the pathognomonic changes in cone dystrophy with supernormal rod ERG and bradyopsia. The clinical phenotype in the disorders can be variable. Mutations in NR2E3 may additionally be associated with phenotypes other than enhanced S-cone syndrome. CONCLUSION : Characteristic ERG changes enable the diagnosis of cone dystrophy with supernormal rod ERG, enhanced S-cone syndrome, and bradyopsia and accurate genetic screening. This review highlights the need for additional nonstandard ERGs to make the diagnosis in two of these disorders.
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Pangeni G, Lämmer R, Tornow RP, Horn FK, Kremers J. On- and off-response ERGs elicited by sawtooth stimuli in normal subjects and glaucoma patients. Doc Ophthalmol 2012; 124:237-48. [PMID: 22457046 DOI: 10.1007/s10633-012-9323-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 03/11/2012] [Indexed: 11/24/2022]
Abstract
The aim of this study is to measure the on- and off-responses and their response asymmetries elicited by sawtooth stimuli in normal subjects and glaucoma patients. Furthermore, the correlation between the ERGs and other functional and structural parameters are investigated. Full-field stimuli were produced using a Ganzfeld bowl with Light Emitting Diodes (LEDs) as light sources. On- and off-response ERGs were recorded from 17 healthy subjects, 12 pre-perimetric and 15 perimetric glaucoma patients using 4-Hz luminance rapid-on and rapid-off sawtooth stimuli (white light; mean luminance 55 cd/m(2)) at 100% contrast. The on- and off-responses were added to study response asymmetries. In addition, flash ERGs were elicited by red stimuli (200 cd/m(2)) on a blue background (10 cd/m(2)). The mean deviations (MD) of the visual field defects were obtained by standard automated perimetry. The retinal nerve fibre layer thickness (RNFLT) was measured with Spectral Domain Optical Coherence Tomography (SOCT). We studied the correlation between ERG response amplitudes, visual field mean deviation (MDs) and RNFLT values. The on-responses showed an initial negative (N-on) followed by a positive (P-on), a late positive (LP-on) and a late negative responses (LN-on). The off-responses showed an initial positive (P-off) a late positive (LP-off) and a late negative response (LN-off). The addition of on- and off-responses revealed an initial positive (P-add) and a late negative response (LN-add). The on-response components (N-on, P-on and LN-on) in the glaucoma patients were relatively similar to those of the control subjects. However, the LP-on was significantly elevated (p = 0.03) in perimetric patients. The LP-off was significantly elevated (p < 0.001), and the amplitude of LN-off was significantly reduced in perimetric patients (p = 0.02). The LN-add amplitude was significantly reduced (p < 0.001) and delayed (p = 0.03) in perimetric patients. The amplitudes of the LN-off and LN-add ERG components were significantly correlated with the PhNR in the flash ERG (LN-off: p = 0.01; LN-add: p < 0.001) and with RNFLT (LN-off: p = 0.006; LN-add: p = 0.001). On- and off-response ERGs and their response asymmetries, elicited by sawtooth stimuli, are altered in the glaucoma patients. The late components are affected. Changes in the late negative components are correlated with structural and other functional changes.
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Affiliation(s)
- Gobinda Pangeni
- Department of Ophthalmology, University Hospital Erlangen, University of Erlangen-Nürnberg, Erlangen, Germany
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Park KH, Chang JH, Park TK, Ohn YH. ON and OFF Responses of the Electroretinogram in Patients with Glaucoma. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2012. [DOI: 10.3341/jkos.2012.53.8.1104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ka Hee Park
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea
| | - Ji Ho Chang
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea
| | - Tae Kwan Park
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea
| | - Young Hoon Ohn
- Department of Ophthalmology, Soonchunhyang University College of Medicine, Bucheon, Korea
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Horn FK, Gottschalk K, Mardin CY, Pangeni G, Jünemann AG, Kremers J. On and off responses of the photopic fullfield ERG in normal subjects and glaucoma patients. Doc Ophthalmol 2011; 122:53-62. [PMID: 21267627 DOI: 10.1007/s10633-011-9258-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 01/07/2011] [Indexed: 12/01/2022]
Abstract
Recent studies suggest a diagnostic value of the photopic negative response (PhNR) with a long-duration stimulus. The aim of this study was to record the on and off responses of the photopic fullfield electroretinogram (ERG) in normal subjects and glaucoma patients. We focused on different waves of the responses after onset and offset of the long-duration stimulus ERG. Photopic fullfield ERGs were recorded in response to a white bright LED flash on a white 20 cd/m(2) background. Stimulus luminances were 40, 60 and 80 cd/m(2). Responses were averaged using a flash duration of 240 ms and an offset period of 500 ms. We examined 19 healthy subjects, 27 patients with glaucomatous optic disc atrophy and 7 ocular hypertensive patients. The amplitudes and implicit times of the on and off responses of the human ERG depended on flash luminance. Comparing patients with glaucoma and healthy subjects for the 60 cd/m² flash, there was a significant change in the PhNRs (at onset: P < 0.01, at offset: P < 0.001) of the d-wave and of the i-wave at offset (P < 0.01). No significant difference was found for peak times of the fullfield ERG and for a- and b-wave amplitudes. PhNR amplitudes were significantly correlated with mean thickness of retinal nerve fibre layer as measured with OCT. In comparison with the normal photopic long-flash ERG, glaucoma patients showed changes in the PhNR amplitude following stimulus onset and in waves following stimulus offset.
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Affiliation(s)
- Folkert K Horn
- Department of Ophthalmology and University Eye Hospital, Friedrich-Alexander University of Erlangen-Nürnberg, Schwabachanlage 6, 91054 Erlangen, Germany.
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Spatial distributions of on- and off-responses determined with the multifocal ERG. Doc Ophthalmol 2009; 120:145-58. [PMID: 19921295 DOI: 10.1007/s10633-009-9205-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 11/03/2009] [Indexed: 10/20/2022]
Abstract
We studied the contribution of retinal on and off-mechanisms in the multifocal electroretinogram (mfERG) by measuring responses to saw tooth stimuli. Six healthy subjects participated in this study. Rapid-on and rapid-off sawtooth stimuli with a period of 427 ms were presented in a multifocal pattern composed of 19 hexagons. The stimuli were interleaved with a blank field of the mean luminance and chromaticity. On- and off-responses were added to extract response asymmetries. The amplitudes of on-, off-, and added-responses were determined for different eccentricities relative to a signal baseline that was defined as the average of the electrical level recorded in two different time windows in which no responses were present. Measurements were repeated with eight different stimulus stretch factors to account for changes in retinal cell density as a function of eccentricity. The amplitudes of all ERG components decreased with increasing eccentricity for all stretch factors. For stretch factors between 0 and 20, responses to the central and immediately adjacent hexagons were large in amplitude. For more peripheral hexagons, the responses were very small or absent. Three components were identified in the on-responses (N20(on), P46(on) and N100(on)). In the offresponses, we found one positive (P20(off)) and one negative (N90(off)) component, whereas in the addition, three components (N20(add), P46(add) and N100(add)) could be observed. The N20(on) and P46(on) amplitudes decreased less steeply with eccentricity than the N100(on) amplitude, whilst the P20(off) and N90(off) amplitudes exhibited a similar decrease with eccentricity. In the addition, the two negative components exhibited a similar decrease in amplitude as a function of eccentricity and decreased more steeply than the positive component. The number of stimulated cones and retinal ganglion cells was estimated from anatomical data and compared with the responses. The spatial properties of the amplitudes of N20(on), P46(on), P20(off), and N90(off) and P46(add) were similar to those of the stimulated cone numbers. The remaining components had spatial characteristics that resembled those of the retinal ganglion cells. It is proposed that the ERG asymmetries revealed in the summed responses have post-receptoral origins, some of them reflecting the activity of the ganglion cell population. The use of sawtooth stimuli provide, similar to the pattern ERG, a way to record the ERG asymmetries.
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The effect of broadband and monochromatic stimuli on the photopic negative response of the electroretinogram in normal subjects and in open-angle glaucoma patients. Doc Ophthalmol 2008; 118:167-77. [PMID: 18932006 DOI: 10.1007/s10633-008-9150-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
The aim was to investigate the effects of monochromatic and broadband stimuli on the amplitude of the photopic negative response (PhNR) and to compare the sensitivities of these stimuli for the detection of ganglion cell damage in glaucoma patients. Forty-one healthy subjects were studied, along with 16 patients with open-angle glaucoma. Photopic electroretinograms (ERGs) were elicited with monochromatic red, amber, green, and broadband white stimuli of progressively brighter intensities in a blue background. Pattern ERGs were also recorded using a 0.8 degrees checkerboard pattern on a 21.6 degrees x 27.8 degrees screen. In the photopic ERGs of the control subjects, the PhNR amplitude was significantly higher (P < 0.01) to red than to monochromatic amber, green, and broadband white stimuli of the same intensity. In glaucoma patients, the percentage of amplitude reduction was greater for the PhNR to red (68%, P < 0.001) than to the broadband stimulus (38%, P = 0.001). The PhNR to red monochromatic stimulus appeared to be a more sensitive parameter, with a larger area enclosed by the receiver-operating characteristic curve (0.97) than for the PhNR to broadband stimulus (0.76). Also, the PhNR to red stimulus showed a more significant correlation with the pattern ERG and the visual field defects (P < 0.05) than the PhNR elicited with broadband stimulus. These findings suggest that ganglion cell activity can be more efficiently evaluated with the PhNR elicited with a red than with a broadband stimulus. The PhNR thus appears to be a promising test for the diagnostics of the ganglion cell dysfunction.
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Stensløkken KO, Milton SL, Lutz PL, Sundin L, Renshaw GMC, Stecyk JAW, Nilsson GE. Effect of anoxia on the electroretinogram of three anoxia-tolerant vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2008; 150:395-403. [PMID: 18579424 DOI: 10.1016/j.cbpa.2008.03.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 03/14/2008] [Accepted: 03/25/2008] [Indexed: 11/28/2022]
Abstract
To survive anoxia, neural ATP levels have to be defended. Reducing electrical activity, which accounts for 50% or more of neural energy consumption, should be beneficial for anoxic survival. The retina is a hypoxia sensitive part of the central nervous system. Here, we quantify the in vivo retinal light response (electroretinogram; ERG) in three vertebrates that exhibit varying degrees of anoxia tolerance: freshwater turtle (Trachemys scripta), epaulette shark (Hemiscyllium ocellatum) and leopard frog (Rana pipiens). A virtually total suppression of ERG in anoxia, probably resulting in functional blindness, has previously been seen in the extremely anoxia-tolerant crucian carp (Carassius carassius). Surprisingly, the equally anoxia-tolerant turtle, which strongly depresses brain and whole-body metabolism during anoxia, exhibited a relatively modest anoxic reduction in ERG: the combined amplitude of turtle ERG waves was reduced by approximately 50% after 2 h. In contrast, the shark b-wave amplitude practically disappeared after 30 min of severe hypoxia, and the frog b-wave was decreased by approximately 75% after 40 min in anoxia. The specific A(1) adenosine receptor antagonist CPT significantly delayed the suppression of turtle ERG, while the hypoxic shark ERG was unaffected by the non-specific adenosine receptor antagonist aminophylline, suggesting adenosinergic involvement in turtle but not in shark.
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Affiliation(s)
- Kåre-Olav Stensløkken
- Surgical Division, Ullevål University Hospital, University of Oslo, NO-0407 Oslo, Norway
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Park SE, Chang JH, Choi KS, Lee JH, Ohn YH. Photopic ON- and OFF- Responses in Korean Normal Subjects. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2008. [DOI: 10.3341/jkos.2008.49.3.471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Su-Eun Park
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Bucheon, Korea
| | - Jee Ho Chang
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Bucheon, Korea
| | - Kyung-Seek Choi
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Bucheon, Korea
| | - Jung-Hee Lee
- Department of Ophthalmology, College of Medicine, Ewha Womans University, Seoul, Korea
| | - Young-Hoon Ohn
- Department of Ophthalmology, College of Medicine, Soonchunhyang University, Bucheon, Korea
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Photopic ON- and OFF-responses in complete type of congenital stationary night blindness in relation to stimulus intensity. Doc Ophthalmol 2007; 117:37-46. [DOI: 10.1007/s10633-007-9101-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 11/03/2007] [Indexed: 10/22/2022]
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