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Manjur SM, Diaz LRM, Lee IO, Skuse DH, Thompson DA, Marmolejos-Ramos F, Constable PA, Posada-Quintero HF. Detecting Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder Using Multimodal Time-Frequency Analysis with Machine Learning Using the Electroretinogram from Two Flash Strengths. J Autism Dev Disord 2024:10.1007/s10803-024-06290-w. [PMID: 38393437 DOI: 10.1007/s10803-024-06290-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2024] [Indexed: 02/25/2024]
Abstract
PURPOSE Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) are conditions that similarly alter cognitive functioning ability and challenge the social interaction, attention, and communication skills of affected individuals. Yet these are distinct neurological conditions that can exhibit diverse characteristics which require different management strategies. It is desirable to develop tools to assist with early distinction so that appropriate early interventions and support may be tailored to an individual's specific requirements. The current diagnostic procedures for ASD and ADHD require a multidisciplinary approach and can be lengthy. This study investigated the potential of electroretinogram (ERG), an eye test measuring retinal responses to light, for rapid screening of ASD and ADHD. METHODS Previous studies identified differences in ERG amplitude between ASD and ADHD, but this study explored time-frequency analysis (TFS) to capture dynamic changes in the signal. ERG data from 286 subjects (146 control, 94 ASD, 46 ADHD) was analyzed using two TFS techniques. RESULTS Key features were selected, and machine learning models were trained to classify individuals based on their ERG response. The best model achieved 70% overall accuracy in distinguishing control, ASD, and ADHD groups. CONCLUSION The ERG to the stronger flash strength provided better separation and the high frequency dynamics (80-300 Hz) were more informative features than lower frequency components. To further improve classification a greater number of different flash strengths may be required along with a discrimination comparison to participants who meet both ASD and ADHD classifications and carry both diagnoses.
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Affiliation(s)
| | | | - Irene O Lee
- Behavioral and Brain Sciences Unit, Population Policy and Practice Program, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - David H Skuse
- Behavioral and Brain Sciences Unit, Population Policy and Practice Program, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Dorothy A Thompson
- Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
- UCL Great Ormond Street Institute for Child Health, University College London, London, UK
| | | | - Paul A Constable
- College of Nursing and Health Sciences, Flinders University, Caring Futures Institute, Adelaide, Australia
| | - Hugo F Posada-Quintero
- Department of Biomedical Engineering, University of Connecticut, 06269, Storrs, CT, USA.
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Fernandes A, Pinto N, Tuna AR, Brardo FM, Pato MV. Pattern electroretinography response in amblyopic adults. Int Ophthalmol 2024; 44:86. [PMID: 38363441 PMCID: PMC10873232 DOI: 10.1007/s10792-024-03042-8] [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: 12/15/2022] [Accepted: 01/13/2024] [Indexed: 02/17/2024]
Abstract
INTRODUCTION Amblyopia is generally a unilateral disorder, defined by at least a difference of two lines of visual acuity between both eyes with the best-corrected visual acuity, a decrease in contrast sensitivity, and a decrease in stereopsis. Pattern electroretinogram (PERG) is a noninvasive technique that provides a retinal biopotential and is a highly sensitive indicator of changes in the macular area. Our aim was to evaluate if there are differences in the retinal response of an amblyopic eye compared with a normal eye (NE). METHODS We evaluated twenty-four adult volunteers, twelve amblyopes (mean 43.42 ± 12.72 years old), and twelve subjects with NE (mean 35.58 ± 12.85 years old). None of the subjects in the two groups had comorbidities. A complete optometric examination was performed including parameters such as visual acuity (VA) by far and near with ETDRS chart, eye alignment with cover test, and evaluation of retinal cells response with PERG. RESULTS The refractive error found in the NE group of subjects had a mean of - 0.95 ± 1.65D, while the amblyopic group showed a mean of - 2.03 ± 4.29D. The VA in amblyopic eyes had a mean of 0.38 ± 0.20 logMAR. Analyzing PERG data, we observed significant differences in the P50-N95 amplitudes of the amblyopic group compared with the NE group (p < 0.0001-amblyopic eye vs. NE; p = 0.039-fellow eye vs. NE). DISCUSSION These findings suggest that amblyopic patients may also present other impairments beyond the visual cortex. PERGs seem to be an important complementary examination in the diagnosis of other impairments in amblyopia.
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Affiliation(s)
- Andresa Fernandes
- Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal.
- Faculty of Health Sciences, Rua Marquês de Ávila E Bolama, CICS-Health Sciences Research Centre, University of Beira Interior, 6201-001, Covilhã, Portugal.
| | - Nuno Pinto
- Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
- Faculty of Health Sciences, Rua Marquês de Ávila E Bolama, CICS-Health Sciences Research Centre, University of Beira Interior, 6201-001, Covilhã, Portugal
| | - Ana Rita Tuna
- Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
- Faculty of Health Sciences, Rua Marquês de Ávila E Bolama, CICS-Health Sciences Research Centre, University of Beira Interior, 6201-001, Covilhã, Portugal
| | - Francisco Miguel Brardo
- Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
- Faculty of Health Sciences, Rua Marquês de Ávila E Bolama, CICS-Health Sciences Research Centre, University of Beira Interior, 6201-001, Covilhã, Portugal
- Department of Physics, University of Beira Interior, Covilhã, Portugal
| | - Maria Vaz Pato
- Faculty of Health Sciences, University of Beira Interior, Covilhã, Portugal
- Faculty of Health Sciences, Rua Marquês de Ávila E Bolama, CICS-Health Sciences Research Centre, University of Beira Interior, 6201-001, Covilhã, Portugal
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Brabec M, Constable PA, Thompson DA, Marmolejo-Ramos F. Group comparisons of the individual electroretinogram time trajectories for the ascending limb of the b-wave using a raw and registered time series. BMC Res Notes 2023; 16:238. [PMID: 37773138 PMCID: PMC10542250 DOI: 10.1186/s13104-023-06535-4] [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: 03/12/2023] [Accepted: 09/25/2023] [Indexed: 10/01/2023] Open
Abstract
OBJECTIVES The electroretinogram is a clinical test commonly used in the diagnosis of retinal disorders with the peak time and amplitude of the a- and b-waves used as the main indicators of retinal function. However, subtle changes that affect the shape of the electroretinogram waveform may occur in the early stages of disease or in conditions that have a neurodevelopmental or neurodegenerative origin. In such cases, we introduce a statistical approach to mathematically model the shape of the electroretinogram waveform that may aid clinicians and researchers using the electroretinogram or other biological signal recordings to identify morphological features in the waveforms that may not be captured by the time or time-frequency domains of the waveforms. We present a statistical graphics-based analysis of the ascending limb of the b-wave (AL-b) of the electroretinogram in children with and without a diagnosis of autism spectrum disorder (ASD) with a narrative explanation of the statistical approach to illustrate how different features of the waveform based on location and scale derived from raw and registered time series can reveal subtle differences between the groups. RESULTS Analysis of the raw time trajectories confirmed findings of previous studies with a reduced and delayed b-wave amplitude in ASD. However, when the individual time trajectories were registered then group differences were visible in the mean amplitude at registered time ~ 0.6 suggesting a novel method to differentiate groups using registration of the ERG waveform.
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Affiliation(s)
- Marek Brabec
- Institute of Computer Science of the Czech Academy of Sciences, Prague, Czech Republic
| | - Paul A Constable
- Flinders University, College of Nursing and Health Sciences, Caring Futures Institute, Adelaide, SA, Australia.
| | - Dorothy A Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic, Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, UK
- UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Fernando Marmolejo-Ramos
- Centre for Change and Complexity in Learning, The University of South Australia, Adelaide, Australia
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Constable PA, Lim JKH, Thompson DA. Retinal electrophysiology in central nervous system disorders. A review of human and mouse studies. Front Neurosci 2023; 17:1215097. [PMID: 37600004 PMCID: PMC10433210 DOI: 10.3389/fnins.2023.1215097] [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: 05/01/2023] [Accepted: 07/17/2023] [Indexed: 08/22/2023] Open
Abstract
The retina and brain share similar neurochemistry and neurodevelopmental origins, with the retina, often viewed as a "window to the brain." With retinal measures of structure and function becoming easier to obtain in clinical populations there is a growing interest in using retinal findings as potential biomarkers for disorders affecting the central nervous system. Functional retinal biomarkers, such as the electroretinogram, show promise in neurological disorders, despite having limitations imposed by the existence of overlapping genetic markers, clinical traits or the effects of medications that may reduce their specificity in some conditions. This narrative review summarizes the principal functional retinal findings in central nervous system disorders and related mouse models and provides a background to the main excitatory and inhibitory retinal neurotransmitters that have been implicated to explain the visual electrophysiological findings. These changes in retinal neurochemistry may contribute to our understanding of these conditions based on the findings of retinal electrophysiological tests such as the flash, pattern, multifocal electroretinograms, and electro-oculogram. It is likely that future applications of signal analysis and machine learning algorithms will offer new insights into the pathophysiology, classification, and progression of these clinical disorders including autism, attention deficit/hyperactivity disorder, bipolar disorder, schizophrenia, depression, Parkinson's, and Alzheimer's disease. New clinical applications of visual electrophysiology to this field may lead to earlier, more accurate diagnoses and better targeted therapeutic interventions benefiting individual patients and clinicians managing these individuals and their families.
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Affiliation(s)
- Paul A. Constable
- College of Nursing and Health Sciences, Caring Futures Institute, Flinders University, Adelaide, SA, Australia
| | - Jeremiah K. H. Lim
- Discipline of Optometry, School of Allied Health, University of Western Australia, Perth, WA, Australia
| | - Dorothy A. Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
- UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Singaram S, Ramakrishnan K, Periyasamy S. Electrodermal signal analysis using continuous wavelet transform as a tool for quantification of sweat gland activity in diabetic kidney disease. Proc Inst Mech Eng H 2023; 237:919-927. [PMID: 37401150 DOI: 10.1177/09544119231184113] [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] [Indexed: 07/05/2023]
Abstract
Sympathetic innervation of the sweat gland (SG) manifests itself electrically as electrodermal activity (EDA), which can be utilized to measure sudomotor function. Since SG exhibits similarities in structure and function with kidneys, quantification of SG activity is attempted through EDA signals. A methodology is developed with electrical stimulation, sampling frequency and signal processing algorithm. One hundred twenty volunteers participated in this study belonging to controls, diabetes, diabetic nephropathy, and diabetic neuropathy. The magnitude and time duration of stimuli is arrived by trial and error in such a way it does not influence controls but triggers SG activity in other Groups. This methodology leads to a distinct EDA signal pattern with changes in frequency and amplitude. The continuous wavelet transform depicts a scalogram to retrieve this information. Further, to distinguish between Groups, time average spectrums are plotted and mean relative energy (MRE) is computed. Results demonstrate high energy value in controls, and it gradually decreases in other Groups indicating a decline in SG activity on diabetes prognosis. The correlation for the acquired results was determined to be 0.99 when compared to the standard lab procedure. Furthermore, Cohen's d value, which is less than 0.25 for all Groups indicating the minimal effect size. Hence the obtained result is validated and statistically analyzed for individual variations. Thus this has the potential to get transformed into a device and could prevent diabetic kidney disease.
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Affiliation(s)
- Sudha Singaram
- Department of Biomedical Engineering, Rajalakshmi Engineering College, Chennai, India
| | - Kalpana Ramakrishnan
- Department of Biomedical Engineering, Rajalakshmi Engineering College, Chennai, India
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Kulyabin M, Zhdanov A, Dolganov A, Maier A. Optimal Combination of Mother Wavelet and AI Model for Precise Classification of Pediatric Electroretinogram Signals. SENSORS (BASEL, SWITZERLAND) 2023; 23:5813. [PMID: 37447663 DOI: 10.3390/s23135813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/14/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023]
Abstract
The continuous advancements in healthcare technology have empowered the discovery, diagnosis, and prediction of diseases, revolutionizing the field. Artificial intelligence (AI) is expected to play a pivotal role in achieving the goals of precision medicine, particularly in disease prevention, detection, and personalized treatment. This study aims to determine the optimal combination of the mother wavelet and AI model for the analysis of pediatric electroretinogram (ERG) signals. The dataset, consisting of signals and corresponding diagnoses, undergoes Continuous Wavelet Transform (CWT) using commonly used wavelets to obtain a time-frequency representation. Wavelet images were used for the training of five widely used deep learning models: VGG-11, ResNet-50, DensNet-121, ResNext-50, and Vision Transformer, to evaluate their accuracy in classifying healthy and unhealthy patients. The findings demonstrate that the combination of Ricker Wavelet and Vision Transformer consistently yields the highest median accuracy values for ERG analysis, as evidenced by the upper and lower quartile values. The median balanced accuracy of the obtained combination of the three considered types of ERG signals in the article are 0.83, 0.85, and 0.88. However, other wavelet types also achieved high accuracy levels, indicating the importance of carefully selecting the mother wavelet for accurate classification. The study provides valuable insights into the effectiveness of different combinations of wavelets and models in classifying ERG wavelet scalograms.
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Affiliation(s)
- Mikhail Kulyabin
- Pattern Recognition Lab, University of Erlangen-Nuremberg, 91058 Erlangen, Germany
| | - Aleksei Zhdanov
- Engineering School of Information Technologies, Telecommunications and Control Systems, Ural Federal University Named after the First President of Russia B. N. Yeltsin, Yekaterinburg 620002, Russia
| | - Anton Dolganov
- Engineering School of Information Technologies, Telecommunications and Control Systems, Ural Federal University Named after the First President of Russia B. N. Yeltsin, Yekaterinburg 620002, Russia
| | - Andreas Maier
- Pattern Recognition Lab, University of Erlangen-Nuremberg, 91058 Erlangen, Germany
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Zhdanov A, Constable P, Manjur SM, Dolganov A, Posada-Quintero HF, Lizunov A. OculusGraphy: Signal Analysis of the Electroretinogram in a Rabbit Model of Endophthalmitis Using Discrete and Continuous Wavelet Transforms. Bioengineering (Basel) 2023; 10:708. [PMID: 37370639 DOI: 10.3390/bioengineering10060708] [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: 05/12/2023] [Revised: 06/04/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND The electroretinogram is a clinical test used to assess the function of the photoreceptors and retinal circuits of various cells in the eye, with the recorded waveform being the result of the summated response of neural generators across the retina. METHODS The present investigation involved an analysis of the electroretinogram waveform in both the time and time-frequency domains through the utilization of the discrete wavelet transform and continuous wavelet transform techniques. The primary aim of this study was to monitor and evaluate the effects of treatment in a New Zealand rabbit model of endophthalmitis via electroretinogram waveform analysis and to compare these with normal human electroretinograms. RESULTS The wavelet scalograms were analyzed using various mother wavelets, including the Daubechies, Ricker, Wavelet Biorthogonal 3.1 (bior3.1), Morlet, Haar, and Gaussian wavelets. Distinctive variances were identified in the wavelet scalograms between rabbit and human electroretinograms. The wavelet scalograms in the rabbit model of endophthalmitis showed recovery with treatment in parallel with the time-domain features. CONCLUSIONS The study compared adult, child, and rabbit electroretinogram responses using DWT and CWT, finding that adult signals had higher power than child signals, and that rabbit signals showed differences in the a-wave and b-wave depending on the type of response tested, while the Haar wavelet was found to be superior in visualizing frequency components in electrophysiological signals for following the treatment of endophthalmitis and may give additional outcome measures for the management of retinal disease.
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Affiliation(s)
- Aleksei Zhdanov
- Machine Learning and Data Analytics Lab, University of Erlangen-Nuremberg, 91052 Erlangen, Germany
- Engineering School of Information Technologies, Telecommunications and Control Systems, Ural Federal University Named after the First President of Russia B. N. Yeltsin, 620002 Yekaterinburg, Russia
| | - Paul Constable
- College of Nursing and Health Sciences, Caring Futures Institute, Flinders University, Adelaide, SA 5042, Australia
| | | | - Anton Dolganov
- Engineering School of Information Technologies, Telecommunications and Control Systems, Ural Federal University Named after the First President of Russia B. N. Yeltsin, 620002 Yekaterinburg, Russia
| | | | - Aleksander Lizunov
- Department of Functional Diagnostics, IRTC Eye Microsurgery Ekaterinburg Center, 620149 Yekaterinburg, Russia
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Comparing the RETeval® portable ERG device with more traditional tabletop ERG systems in normal subjects and selected retinopathies. Doc Ophthalmol 2022; 146:137-150. [PMID: 36273363 PMCID: PMC10082128 DOI: 10.1007/s10633-022-09903-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/28/2022] [Indexed: 11/03/2022]
Abstract
Abstract
Purpose
Our study aimed to determine if ISCEV standard-like ERGs recorded with the LKC RETeval® portable ERG unit compared to those obtained using the more traditional tabletop unit.
Methods
ERGs recorded from normal subjects and patients affected with retinal ON and OFF pathway anomalies were compared. Analysis included peak time and amplitude measurements as well as time–frequency domain analysis with the discrete wavelet transform of waveforms obtained with the two systems.
Results
Although both systems were similarly able to record reliable and highly reproducible ERG responses, there were major discrepancies in ERG responses between the portable and tabletop units, pointing toward a weaker stimulation of the retinal OFF pathway with the portable RETeval® unit.
Conclusion
The portable RETeval® unit appears to be able to record highly reproducible and diagnostically useful clinical ERGs, albeit with some significant differences in waveform composition compared to those obtained with more standard tabletop systems. Given the unknown origin of these waveform discrepancies, if left uncorrected, these differences could potentially lead to erroneous interpretation when used in the clinical context and/or compared to ERGs recorded using more traditional table top units. Clearly, more research is warranted before handheld devices, such as the RETeval®, can be homologated as a diagnostically sound ERG devices.
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Gauthier M, Simard AB, Polosa A, Dorfman AL, Qian CX, Lina JM, Lachapelle P. Resting state electroretinography: An innovative approach to intrinsic retinal function monitoring. Front Physiol 2022; 13:931147. [PMID: 36091360 PMCID: PMC9462834 DOI: 10.3389/fphys.2022.931147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/28/2022] [Indexed: 12/05/2022] Open
Abstract
The electroretinogram (ERG) represents the biopotential evoked by the retina in response to a light stimulus. The flash evoked ERG (fERG) is the ERG modality most frequently used clinically to diagnose and monitor retinal disorders. We hereby present a new method to record spontaneous retinal activity, without the use of a flash stimulus, that we named the resting-state ERG (rsERG). The recordings were done in normal subjects under light- and dark-adaptation and with different background light conditions (i.e., variations of wavelength and intensity). Additionally, rsERG recordings were obtained in five patients with retinopathies. The signals were subsequently analyzed in the frequency domain, extracting both periodic (i.e., frequency peaks) and aperiodic (i.e., background trend) components of the signal. The later was further assessed through a multifractal analysis using Wavelet Leaders. Results show that, irrespective of the recording conditions used, the rsERG always includes the same 90 Hz component; a frequency component also present in the fERG response, suggesting a retinally-intrinsic origin. However, in addition, the fERGs also includes a low-frequency component which is absent in the rsERGs, a finding supporting a retinally-induced origin. Comparing rsERGs with fERGs in selected patients with various retinal disorders indicates that the two retinal signals are not always similarly affected (either as a result of underlying retinal pathology or otherwise), suggesting an added value in the assessment of retinal function. Thus, the rsERG could have a similar role in clinical visual electrophysiology as that of the resting-state EEG in neurology namely, to quantify changes in spontaneous activity that result from a given disease processes.
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Affiliation(s)
- Mercedes Gauthier
- >
Département de Génie Électrique, École de Technologie Supérieure, Montreal, QC, Canada
- Department of Ophthalmology and Visual Sciences, Research Institute of the McGill University Health Centre/Montreal Children’s Hospital, Montreal, QC, Canada
- *Correspondence: Mercedes Gauthier,
| | - Antoine Brassard Simard
- >
Département de Génie Électrique, École de Technologie Supérieure, Montreal, QC, Canada
- Department of Ophthalmology and Visual Sciences, Research Institute of the McGill University Health Centre/Montreal Children’s Hospital, Montreal, QC, Canada
| | - Anna Polosa
- Department of Ophthalmology and Visual Sciences, Research Institute of the McGill University Health Centre/Montreal Children’s Hospital, Montreal, QC, Canada
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, University de Montréal, Montréal, QC, Canada
| | - Allison L. Dorfman
- Department of Ophthalmology and Visual Sciences, Research Institute of the McGill University Health Centre/Montreal Children’s Hospital, Montreal, QC, Canada
- Department of Ophthalmology, Centre Hospitalier Universitaire Sainte-Justine Research Center, Montréal, QC, Canada
| | - Cynthia X. Qian
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Centre, University de Montréal, Montréal, QC, Canada
- Department of Ophthalmology, Centre Hospitalier Universitaire Sainte-Justine Research Center, Montréal, QC, Canada
| | - Jean-Marc Lina
- >
Département de Génie Électrique, École de Technologie Supérieure, Montreal, QC, Canada
- Centre de Recherches en Mathématiques, Montréal, QC, Canada
| | - Pierre Lachapelle
- Department of Ophthalmology and Visual Sciences, Research Institute of the McGill University Health Centre/Montreal Children’s Hospital, Montreal, QC, Canada
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Constable PA, Marmolejo-Ramos F, Gauthier M, Lee IO, Skuse DH, Thompson DA. Discrete Wavelet Transform Analysis of the Electroretinogram in Autism Spectrum Disorder and Attention Deficit Hyperactivity Disorder. Front Neurosci 2022; 16:890461. [PMID: 35733935 PMCID: PMC9207322 DOI: 10.3389/fnins.2022.890461] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/09/2022] [Indexed: 12/30/2022] Open
Abstract
Background To evaluate the electroretinogram waveform in autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) using a discrete wavelet transform (DWT) approach. Methods A total of 55 ASD, 15 ADHD and 156 control individuals took part in this study. Full field light-adapted electroretinograms (ERGs) were recorded using a Troland protocol, accounting for pupil size, with five flash strengths ranging from –0.12 to 1.20 log photopic cd.s.m–2. A DWT analysis was performed using the Haar wavelet on the waveforms to examine the energy within the time windows of the a- and b-waves and the oscillatory potentials (OPs) which yielded six DWT coefficients related to these parameters. The central frequency bands were from 20–160 Hz relating to the a-wave, b-wave and OPs represented by the coefficients: a20, a40, b20, b40, op80, and op160, respectively. In addition, the b-wave amplitude and percentage energy contribution of the OPs (%OPs) in the total ERG broadband energy was evaluated. Results There were significant group differences (p < 0.001) in the coefficients corresponding to energies in the b-wave (b20, b40) and OPs (op80 and op160) as well as the b-wave amplitude. Notable differences between the ADHD and control groups were found in the b20 and b40 coefficients. In contrast, the greatest differences between the ASD and control group were found in the op80 and op160 coefficients. The b-wave amplitude showed both ASD and ADHD significant group differences from the control participants, for flash strengths greater than 0.4 log photopic cd.s.m–2 (p < 0.001). Conclusion This methodological approach may provide insights about neuronal activity in studies investigating group differences where retinal signaling may be altered through neurodevelopment or neurodegenerative conditions. However, further work will be required to determine if retinal signal analysis can offer a classification model for neurodevelopmental conditions in which there is a co-occurrence such as ASD and ADHD.
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Affiliation(s)
- Paul A. Constable
- College of Nursing and Health Sciences, Caring Futures Institute, Flinders University, Adelaide, SA, Australia
- *Correspondence: Paul A. Constable,
| | - Fernando Marmolejo-Ramos
- Centre for Change and Complexity in Learning, The University of South Australia, Adelaide, SA, Australia
| | - Mercedes Gauthier
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine and Health Sciences, McGill University, Montréal, QC, Canada
| | - Irene O. Lee
- Behavioural and Brain Sciences Unit, Population, Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - David H. Skuse
- Behavioural and Brain Sciences Unit, Population, Policy and Practice Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Dorothy A. Thompson
- The Tony Kriss Visual Electrophysiology Unit, Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Trust, London, United Kingdom
- UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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Suppression of electromagnetic interference in electroretinography from a patient with an implanted left ventricular assist device (LVAD). Doc Ophthalmol 2022; 144:137-145. [PMID: 35247110 DOI: 10.1007/s10633-022-09865-z] [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: 10/21/2021] [Accepted: 01/28/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE A left ventricular assist device (LVAD) is an implantable cardiac pump that uses a magnetically-levitating rotor to pump blood into circulation for patients with congestive heart failure. The continuous high-frequency motion of the pump can cause significant interference in electroretinography (ERG) recordings. We evaluate filtering methods to improve ERG quality in the presence of LVAD interference. METHODS A patient with an implanted LVAD was referred to our clinic for ERG testing on suspicion of a retinal dystrophy. Full-field ERG (ffERG) and pattern ERG (pERG) were performed according to ISCEV standards. Recordings were acquired once in full-bandwidth mode and again in low-bandwidth mode. Digital low-pass and band-stop filtering were performed to mitigate ERG interference. Post-processing was also evaluated in a control subject with no implanted device. RESULTS High-frequency interference was present in all ERG recordings and corresponded to the speed settings of the pump. When applied in post-processing, both low-pass and band-stop filters suppressed the interference and presented readable ERGs without affecting peak times or amplitudes. By contrast, when recording in low-bandwidth mode, the filter drop-off was not steep enough to completely remove the interference and peak delays were introduced that could not be readily corrected. CONCLUSIONS LVAD interference in ERG waveforms can be successfully removed using simple digital filters. If post hoc data processing capabilities are unavailable, a large amount of interference can be removed by narrowing the acquisition bandwidth and averaging additional repeats of each stimulus response.
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Righetti G, Kempf M, Braun C, Jung R, Kohl S, Wissinger B, Zrenner E, Stingl K, Stingl K. Oscillatory Potentials in Achromatopsia as a Tool for Understanding Cone Retinal Functions. Int J Mol Sci 2021; 22:12717. [PMID: 34884517 PMCID: PMC8657736 DOI: 10.3390/ijms222312717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 11/25/2022] Open
Abstract
Achromatopsia (ACHM) is an inherited autosomal recessive disease lacking cone photoreceptors functions. In this study, we characterize the time-frequency representation of the full-field electroretinogram (ffERG) component oscillatory potentials (OPs), to investigate the connections between photoreceptors and the inner retinal network using ACHM as a model. Time-frequency characterization of OPs was extracted from 52 controls and 41 achromat individuals. The stimulation via ffERG was delivered under dark-adaptation (DA, 3.0 and 10.0 cd·s·m-2) to assess mixed rod-cone responses. The ffERG signal was subsequently analyzed using a continuous complex Morlet transform. Time-frequency maps of both DA conditions show the characterization of OPs, disclosing in both groups two distinct time-frequency windows (~70-100 Hz and >100 Hz) within 50 ms. Our main result indicates a significant cluster (p < 0.05) in both conditions of reduced relative power (dB) in ACHM people compared to controls, mainly at the time-frequency window >100 Hz. These results suggest that the strongly reduced but not absent activity of OPs above 100 Hz is mostly driven by cones and only in small part by rods. Thus, the lack of cone modulation of OPs gives important insights into interactions between photoreceptors and the inner retinal network and can be used as a biomarker for monitoring cone connection to the inner retina.
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Affiliation(s)
- Giulia Righetti
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076 Tübingen, Germany; (M.K.); (R.J.); (K.S.); (K.S.)
| | - Melanie Kempf
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076 Tübingen, Germany; (M.K.); (R.J.); (K.S.); (K.S.)
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tübingen, Germany;
| | - Christoph Braun
- MEG-Center, University of Tübingen, 72076 Tübingen, Germany;
- CIMeC, Center for Mind/Brain Science, University of Trento, 38123 Trento, Italy
| | - Ronja Jung
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076 Tübingen, Germany; (M.K.); (R.J.); (K.S.); (K.S.)
| | - Susanne Kohl
- Molecular Genetics Laboratory, Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (S.K.); (B.W.)
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany; (S.K.); (B.W.)
| | - Eberhart Zrenner
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tübingen, Germany;
- Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, 72076 Tübingen, Germany
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tübingen, Germany
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076 Tübingen, Germany; (M.K.); (R.J.); (K.S.); (K.S.)
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tübingen, Germany;
| | - Krunoslav Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076 Tübingen, Germany; (M.K.); (R.J.); (K.S.); (K.S.)
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tübingen, Germany;
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Gao M, Telles Salgueiro Barboni M, Fix Ventura D, Nagy BV. Effects of fixed cutoff filtering on dark- and light-adapted ERG components and the application of variable cutoff filter. Doc Ophthalmol 2021; 144:191-202. [PMID: 34559355 PMCID: PMC9192464 DOI: 10.1007/s10633-021-09853-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/10/2021] [Indexed: 11/29/2022]
Abstract
Purpose Human oscillatory potentials (OPs) are derived from dark-adapted (DA) electroretinograms (ERGs) with fixed frequency cutoff filters while light-adapted (LA) OPs are generally not isolated from ERGs. Our purpose was to analyze the effect of cutoff frequencies on DA and LA ERG components using a series of fixed and variable filters. Methods DA and LA ERGs were recorded from 10 healthy eyes of 10 subjects (mean age = 20.5 ± 6.7 years) following ISCEV standards. Each signal was filtered in the Fourier domain to acquire slow (a- and b-waves; below cutoff frequency) and fast (OPs; above cutoff frequency) components. Fixed cutoff frequencies ranged from 60 to 105 Hz and a variable cutoff frequency was calculated. Results were analyzed with statistical tests and specific models. Results DA ERG components were slightly influenced by the filter cutoff frequency. In contrast, fixed and variable filters significantly changed LA components: the lower the cutoff frequency the smaller the b-wave and OP3 and the higher the OP2/OP4 amplitudes. Analyzing the filter frequency limits a transition range between 68.9 Hz and 83.9 Hz was observed where amplitudes vary. Conclusions The present report shows that DA OPs may be isolated from ERGs using filtering procedures with high-pass cutoff frequency at about 75 Hz as recommended by ISCEV. On the other hand, the spectral distribution of low-frequency and high-frequency LA ERG components may overlap. Accordingly, filtering the signal using different cutoff frequencies is not necessarily separating b-wave and OPs.
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Affiliation(s)
- Min Gao
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary
| | - Mirella Telles Salgueiro Barboni
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary.,Department of Experimental Psychology, University of Sao Paulo, Sao Paulo, Brazil
| | - Dora Fix Ventura
- Department of Experimental Psychology, University of Sao Paulo, Sao Paulo, Brazil
| | - Balázs Vince Nagy
- Department of Mechatronics, Optics and Mechanical Engineering Informatics, Budapest University of Technology and Economics, Budapest, Hungary.
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Bakhshi S, Behbahani S, Daftarian N. Application of a Mapping Method in the Analysis of Electroretinogram in Patients with Retinitis Pigmentosa. Semin Ophthalmol 2021; 37:351-357. [PMID: 34499573 DOI: 10.1080/08820538.2021.1967411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Retinitis pigmentosa (RP) is a group of degenerative retinal diseases characterized by mutations in genes affecting retinal pigment epithelium (RPE) function, as well as mutations directly involving photoreceptors. This paper aims to evaluate a nonlinear method to distinguish between the RP and normal eye based on the Electroretinogram (ERG) signal. METHOD ERG signal was recorded from 28 eyes of patients with the RP and 32 normal eyes. The ERG signal consists of four different stimuli, including two dark-adapted and two light-adapted stimuli. The time-domain analysis includes the amplitude and implicit time to consider the robustness of the nonlinear method. A parabolic mapping method was performed, and two criteria (Theta angle and density) extracted from the parabola were compared for both groups. RESULTS The results showed that a-wave's amplitude and implicit time significantly changed in the dark- and light-adapted stimuli. The amplitude of the b-wave showed significant changes in all stimuli. However, the implicit time of b-wave had a significant increase only in the dark-adapted 3.0 ERG. Both nonlinear criteria showed significant changes in the RP group for all the stimuli. The p-values of dark-adapted 3.0 (p = .0121), dark-adapted 10.0 (p = .0014), light-adapted 3.0 (p = .0119), and flicker 30 Hz (p = .0323) showed significant differences. Using the density criterion, the statistical test demonstrated a significant difference between the RP and healthy normal group in dark-adapted 3.0 (p = .0076), dark-adapted 10.0 (p = .0024), light-adapted 3.0 (p = .0021), and flicker 30 Hz (p = .0165). CONCLUSION The proposed features have made it possible to distinguish between healthy and RP eyes. This method might be helpful in early diagnosis.
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Affiliation(s)
- Samiyeh Bakhshi
- Department of Biomedical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Soroor Behbahani
- Department of Biomedical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran
| | - Narsis Daftarian
- Ocular Tissue Engineering Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Sabbaghi H, Behbahani S, Daftarian N, Ahmadieh H. New criteria for evaluation of electroretinogram in patients with retinitis pigmentosa. Doc Ophthalmol 2021; 143:271-281. [PMID: 34191198 DOI: 10.1007/s10633-021-09843-x] [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: 12/25/2020] [Accepted: 05/21/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND Electroretinogram (ERG) plays an essential role in the diagnosis of retinal disease. Choosing appropriate methods could extract valuable information from ERG. In this study, a new criterion based on time-frequency domain analysis was proposed to investigate the retina in retinitis pigmentosa (RP) patients. MATERIALS AND METHODS The total number of 16 eyes from eight RP patients and 20 eyes from age-matched healthy subjects were assessed. The signals included photopic and scotopic ERGs. Continuous wavelet transform was applied to ERGs. Dominant frequencies were extracted, and the contours related to these dominant frequencies were selected. As a new criterion, the areas related to dominant frequency contours were considered a feature to differentiate the RP and normal groups. To better evaluate the proposed criterion results, the time-domain analysis characteristics of ERG were also considered. RESULTS The results showed an increase in implicit time and reduced amplitude in RP patients (P < 0.05). A significant decrease of dominant frequencies and increasing their occurrence time were seen in ERG of RP patients. Also, in RP patients, the third dominant frequency was disappeared from the three main frequencies observed in photopic ERGs of normal subjects. The area criterion showed a significant decrease in RP groups (P < 0.05). CONCLUSION RP can cause changes in the time and time-frequency components of the ERG. The area index could represent a new view of the characteristics of the ERG in the time-frequency domain. This criterion can help the ophthalmologist to have a better evaluation of retinal disease.
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Affiliation(s)
- Hamideh Sabbaghi
- Ophthalmic Epidemiology Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soroor Behbahani
- Department of Biomedical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.
| | - Narsis Daftarian
- Ocular Tissue Engineering Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Gauthier M, Brassard-Simard A, Gauvin M, Lachapelle P, Lina JM. Multi-Angular Electroretinography (maERG): Topographic mapping of the retinal function combining real and virtual electrodes. IEEE Trans Biomed Eng 2021; 68:3173-3183. [PMID: 33905319 DOI: 10.1109/tbme.2021.3075617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
GOAL The full-field electroretinogram (ffERG) is an objective tool to assess global retinal function, though as it is currently done, it is unable to localize sources of retinal dysfunction or damage. To overcome this, we have developed a new way to record multiple spatial derivations of the ERG using the rotating capability of the eye, thus creating virtual electrodes. We have termed this the multi-angular ERG (or maERG). With only 3 real electrodes and 11 varying gaze positions, we create 33 virtual electrodes. METHODS We created a realistic electrophysiological and anatomical eye model (i.e. forward model) to reconstruct the retinal activity (i.e. inverse problem) from the 33 virtual electrodes. We simulated 2 pathological scenarios (central and peripheral scotomas), which were compared to their respective theoretical source configurations using an Area under Receiver Operator Characteristic curve metric. RESULTS Our simulations show that the low-resolution brain electromagnetic tomography algorithm (LORETA) is the best method tested to reconstruct retinal sources when compared to the Minimum Norm Estimate algorithm. Furthermore, a signal to noise ratio of 50dB is needed to accurately reconstruct the retinas functional map. CONCLUSION Our proposed maERG recording method, combined with our solution to the electromagnetic inverse problem enables us to reconstruct the functional map of the human retina. SIGNIFICANCE We believe that this new functional retinal imaging technique will permit earlier detection of retinal malfunction and consequently optimize the clinical monitoring of patients affected with retinopathies.
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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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Effects of obesity on time-frequency components of electroretinogram signal using continuous wavelet transform. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2020.102398] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Kim K, Kim HJ, Zhang H, Park W, Meyer D, Kim MK, Kim B, Park H, Xu B, Kollbaum P, Boudouris BW, Lee CH. All-printed stretchable corneal sensor on soft contact lenses for noninvasive and painless ocular electrodiagnosis. Nat Commun 2021; 12:1544. [PMID: 33750806 PMCID: PMC7943761 DOI: 10.1038/s41467-021-21916-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 12/17/2020] [Indexed: 02/03/2023] Open
Abstract
Electroretinogram examinations serve as routine clinical procedures in ophthalmology for the diagnosis and management of many ocular diseases. However, the rigid form factor of current corneal sensors produces a mismatch with the soft, curvilinear, and exceptionally sensitive human cornea, which typically requires the use of topical anesthesia and a speculum for pain management and safety. Here we report a design of an all-printed stretchable corneal sensor built on commercially-available disposable soft contact lenses that can intimately and non-invasively interface with the corneal surface of human eyes. The corneal sensor is integrated with soft contact lenses via an electrochemical anchoring mechanism in a seamless manner that ensures its mechanical and chemical reliability. Thus, the resulting device enables the high-fidelity recording of full-field electroretinogram signals in human eyes without the need of topical anesthesia or a speculum. The device, superior to clinical standards in terms of signal quality and comfortability, is expected to address unmet clinical needs in the field of ocular electrodiagnosis.
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Affiliation(s)
- Kyunghun Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Ho Joong Kim
- Charles D. Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA
| | - Haozhe Zhang
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA
| | - Woohyun Park
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Dawn Meyer
- School of Optometry, Indiana University, Bloomington, IN, USA
| | - Min Ku Kim
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Bongjoong Kim
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
| | - Heun Park
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Baoxing Xu
- Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, USA.
| | - Pete Kollbaum
- School of Optometry, Indiana University, Bloomington, IN, USA.
| | - Bryan W Boudouris
- Charles D. Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN, USA.
- Department of Chemistry, Purdue University, West Lafayette, IN, USA.
| | - Chi Hwan Lee
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA.
- School of Materials Engineering, Purdue University, West Lafayette, IN, USA.
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Ahmadieh H, Behbahani S, Safi S. Continuous wavelet transform analysis of ERG in patients with diabetic retinopathy. Doc Ophthalmol 2020; 142:305-314. [PMID: 33226538 DOI: 10.1007/s10633-020-09805-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/10/2020] [Indexed: 01/02/2023]
Abstract
PURPOSE Diabetic retinopathy (DR) is one of the leading causes of blindness worldwide. Non-proliferative diabetic retinopathy (NPDR) is a stage of the disease that contains morphological and functional disruption of the retinal vasculature and dysfunction of retinal neurons. This study aimed to compare time and time-frequency-domain analysis in the evaluation of electroretinograms (ERGs) in subjects with NPDR. METHOD The ERG responses were recorded in 16 eyes from 12 patients with NPDR and 24 eyes from 12 healthy subjects as the control group. The implicit time, amplitude, and time-frequency-domain parameters of photopic and scotopic ERGs were analyzed. RESULTS The implicit times of b-waves in the dark-adapted 10.0 (P = 0.0513) and light-adapted 3.0 (P = 0.0414) were significantly increased in the NPDR group. The amplitudes of a- and b-wave showed a significantly decreased dark-adapted 10.0 (P = 0.0212; P = 0.0133) and light-adapted 3.0 (P = 0.0517; P = 0.0021) ERG of the NPDR group. The Cohen's d effect size had higher values in the amplitude of dark-adapted 10.0 b-wave (|d|= 1.8058) and amplitude of light-adapted 3.0 b-wave (|d|= 1.9662). The CWT results showed that the frequency ranges of the dominant components in dark-adapted 10.0 and light-adapted 3.0 ERG were decreased in the NPDR group compared to the healthy group (P < 0.05). The times associated with the NDPR group's dominant components were increased compared to normal eyes in both dark-adapted 10.0 and light-adapted 3.0 ERG (P < 0.05). All Cohen's d effect sizes of the implicit times and dominant frequency components were on a large scale (|d|> 1). CONCLUSION These findings suggest that the time and time-frequency parameters of both photopic and scotopic ERGs can be good indicators for DR. However, time-frequency-domain analysis could present more information might be helpful in the assessment of the DR severity.
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Affiliation(s)
- Hamid Ahmadieh
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soroor Behbahani
- Department of Biomedical Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran.
| | - Sare Safi
- Ophthalmic Epidemiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Structural imaging of the retina in psychosis spectrum disorders: current status and perspectives. Curr Opin Psychiatry 2020; 33:476-483. [PMID: 32639357 DOI: 10.1097/yco.0000000000000624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Structural changes of the retina in schizophrenia and other psychotic disorders seem plausible as these conditions are accompanied by widespread morphological abnormalities of the brain. Advances in structural retinal imaging have led to the possibility of precise quantification of individual retinal layers, using optical coherence tomography (OCT) scanners. RECENT FINDINGS The aggregation of information related to OCT findings in schizophrenia has resulted in three metaanalyses, which are currently described. Areas where retinal changes were reported include retinal nerve fiber layer (RNFL), ganglion cell layer complex (GCC), macular volume, and macular thickness, but findings on affected retinal segments vary to some extent across studies. Discrepancies in individual studies could be because of small samples, heterogeneity within schizophrenia (phase of the illness, illness duration, predominant symptomatology), inconsistent reporting of antipsychotic therapy, insufficient control of confounding variables (somatic comorbidities, smoking, and so on), and use of the different types of OCT scanners. SUMMARY Exploration of potential disturbances in retinal architecture could provide new insights into neuronal changes associated with psychosis spectrum disorders, with potential to elucidate the nature and timing of developmental, progressive, inflammatory, and degenerative aspects of neuropathology and pathophysiology, and to assist with characterizing heterogeneity and facilitating personalized treatment approaches.
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Takemura H, Yuasa K, Amano K. Predicting Neural Response Latency of the Human Early Visual Cortex from MRI-Based Tissue Measurements of the Optic Radiation. eNeuro 2020; 7:ENEURO.0545-19.2020. [PMID: 32424054 PMCID: PMC7333978 DOI: 10.1523/eneuro.0545-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 12/16/2022] Open
Abstract
Although the non-invasive measurement of visually evoked responses has been extensively studied, the structural basis of variabilities in latency in healthy humans is not well understood. We investigated how tissue properties of optic radiation could predict interindividual variability in the latency of the initial visually evoked component (C1), which may originate from the primary visual cortex (V1). We collected C1 peak latency data using magnetoencephalography (MEG) and checkerboard stimuli, and multiple structural magnetic resonance imaging (MRI) data from 20 healthy subjects. While we varied the contrast and position of the stimuli, the C1 measurement was most reliable when high-contrast stimuli were presented to the lower visual field (LVF). We then attempted to predict interindividual variability in C1 peak latency in this stimulus condition with a multiple regression model using MRI parameters along the optic radiation. We found that this model could predict >20% of variance in C1 latency, when the data were averaged across the hemispheres. The model using the corticospinal tract did not predict variability in C1 latency, suggesting that there is no evidence for generalization to a non-visual tract. In conclusion, our results suggest that the variability in neural latencies in the early visual cortex in healthy subjects can be partly explained by tissue properties along the optic radiation. We discuss the challenges of predicting neural latency using current structural neuroimaging methods and other factors that may explain interindividual variance in neural latency.
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Affiliation(s)
- Hiromasa Takemura
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita-shi, Osaka 565-0871, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita-shi, Osaka 565-0871, Japan
| | - Kenichi Yuasa
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita-shi, Osaka 565-0871, Japan
- Department of Psychology, New York University, New York, NY 10003
| | - Kaoru Amano
- Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology, and Osaka University, Suita-shi, Osaka 565-0871, Japan
- Graduate School of Frontier Biosciences, Osaka University, Suita-shi, Osaka 565-0871, Japan
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Oscillatory potentials in patients with birdshot chorioretinopathy. Doc Ophthalmol 2020; 141:293-305. [PMID: 32542469 DOI: 10.1007/s10633-020-09776-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 06/03/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE The electroretinogram (ERG) has proven to be useful in the evaluation and monitoring of patients with posterior uveitis. ERG oscillatory potentials (OPs) are sometimes reduced in many uveitic eyes with otherwise grossly normal ERG responses. This study compares ERG parameters, including OPs, between patients with birdshot chorioretinopathy, other posterior uveitis, and controls. METHODS This was a retrospective case-control study. Sixty-four patients seen at a clinical practice had a total of 93 visits during which ERG was performed on both eyes. ERG data from 93 age-matched controls were also collected. Root-mean-squared (RMS) energy of the OPs was calculated using Fourier analysis for 88 patients and 88 age-matched controls for whom complete data were available. Photopic flicker amplitudes, photopic flicker latencies, scotopic b-wave amplitudes, and OP RMS values were compared between patients and controls. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves. RESULTS The mean ages of patients and controls were 55.9 ± 10.8 (SD) years and 55.1 ± 11.5, respectively. 83% of the patients had a diagnosis of BCR. The mean OP RMS value was significantly different in patients (15.6 µV ± 9.7 µV) versus control eyes (33.0 µV ± 12.7 µV), p < 0.001. Area under the ROC curves (AUROC) was 0.75 for photopic flicker amplitudes, 0.77 for photopic flicker latencies, 0.72 for scotopic b-wave amplitudes, and 0.88 for OP RMS. AUROC was significantly different between OP RMS and photopic flicker amplitudes (p < 0.001), between OP RMS and flicker latencies (p = 0.0032), and between OP RMS and scotopic b-wave amplitudes (p < 0.0001). CONCLUSION Analysis of OPs shows greater sensitivity and specificity in the diagnosis and evaluation of patients with birdshot chorioretinopathy than photopic and scotopic ERG amplitudes and photopic flicker latencies.
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Silverstein SM, Demmin DL, Schallek JB, Fradkin SI. Measures of Retinal Structure and Function as Biomarkers in Neurology and Psychiatry. Biomark Neuropsychiatry 2020. [DOI: 10.1016/j.bionps.2020.100018] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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Moghimi P, Jimenez NT, McLoon LK, Netoff TI, Lee MS, MacDonald A, Miller RF. Electoretinographic evidence of retinal ganglion cell-dependent function in schizophrenia. Schizophr Res 2020; 219:34-46. [PMID: 31615740 PMCID: PMC7442157 DOI: 10.1016/j.schres.2019.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 02/02/2023]
Abstract
Schizophrenia is a complex disorder that is diagnosed mainly with clinical observation and evaluation. Recent studies suggest that many people with schizophrenia have abnormalities in the function of the N-methyl-d-aspartate receptor (NMDAR). The retina is part of the central nervous system and expresses the NMDAR, raising the possibility of the early detection of NMDAR-related schizophrenia by detecting differences in retinal function. As a first-step, we used two non-invasive outpatient tests of retinal function, the photopic negative response (PhNR) of the light-adapted flash-electroretinogram (PhNR-fERG) and the pattern ERG (PERG), to test individuals with schizophrenia and controls to determine if there were measurable differences between the two populations. The PhNR-fERG showed that males with schizophrenia had a significant increase in the variability of the overall response, which was not seen in the females with schizophrenia. Additionally at the brightest flash strength, there were significant increases in the PhNR amplitude in people with schizophrenia that were maximal in controls. Our results show measurable dysfunction of retinal ganglion cells (RGCs) in schizophrenia using the PhNR-fERG, with a good deal of variability in the retinal responses of people with schizophrenia. The PhNR-fERG holds promise as a method to identify individuals more at risk for developing schizophrenia, and may help understand heterogeneity in etiology and response to treatment.
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Affiliation(s)
- Pantea Moghimi
- Department of Neurobiology, University of Chicago, Chicago, IL, United States of America
| | - Nathalia Torres Jimenez
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States of America
| | - Linda K. McLoon
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States of America
| | - Theoden I. Netoff
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States of America
| | - Michael S. Lee
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States of America
| | - Angus MacDonald
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States of America; Departments of Psychology and Psychiatry, University of Minnesota, Minneapolis, MN, United States of America.
| | - Robert F. Miller
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Neuroscience, University of Minnesota, Minneapolis, MN, United States of America,Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States of America
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Silverstein SM, Fradkin SI, Demmin DL. Schizophrenia and the retina: Towards a 2020 perspective. Schizophr Res 2020; 219:84-94. [PMID: 31708400 PMCID: PMC7202990 DOI: 10.1016/j.schres.2019.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 09/28/2019] [Accepted: 09/30/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Differences between people with schizophrenia and psychiatrically healthy controls have been consistently demonstrated on measures of retinal function such as electroretinography (ERG), and measures of retinal structure such as optical coherence tomography (OCT). Since our 2015 review of this literature, multiple new studies have been published using these techniques. At the same time, the accumulation of data has highlighted the "fault lines" in these fields, suggesting methodological considerations that need greater attention in future studies. METHODS We reviewed studies of ERG and OCT in schizophrenia, as well as data from studies whose findings are relevant to interpreting these papers, such as those on effects of the following on ERG and OCT data: comorbid medical conditions that are over-represented in schizophrenia, smoking, antipsychotic medication, substance abuse, sex and gender, obesity, attention, motivation, and influences of brain activity on retinal function. RESULTS Recent ERG and OCT studies continue to support the hypothesis of retinal structural and functional abnormalities in schizophrenia, and suggest that these are relevant to understanding broader aspects of pathophysiology, neurodevelopment, and neurodegeneration in this disorder. However, there are differences in findings which suggest that the effects of multiple variables on ERG and OCT data need further clarification. CONCLUSIONS The retina, as the only component of the CNS that can be imaged directly in live humans, has potential to clarify important aspects of schizophrenia. With greater attention to specific methodological issues, the true potential of ERG and OCT as biomarkers for important clinical phenomena in schizophrenia should become apparent.
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Affiliation(s)
- Steven M Silverstein
- Rutgers University Behavioral Health Care, United States; Rutgers University, Robert Wood Johnson Medical School, Departments of Psychiatry and Ophthalmology, United States.
| | | | - Docia L Demmin
- Rutgers University, Department of Psychology, United States.
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Abstract
BACKGROUND Differences between people with schizophrenia and psychiatrically healthy controls have been consistently demonstrated on measures of retinal function such as electroretinography (ERG), and measures of retinal structure such as optical coherence tomography (OCT). Since our 2015 review of this literature, multiple new studies have been published using these techniques. At the same time, the accumulation of data has highlighted the "fault lines" in these fields, suggesting methodological considerations that need greater attention in future studies. METHODS We reviewed studies of ERG and OCT in schizophrenia, as well as data from studies whose findings are relevant to interpreting these papers, such as those on effects of the following on ERG and OCT data: comorbid medical conditions that are over-represented in schizophrenia, smoking, antipsychotic medication, substance abuse, sex and gender, obesity, attention, motivation, and influences of brain activity on retinal function. RESULTS Recent ERG and OCT studies continue to support the hypothesis of retinal structural and functional abnormalities in schizophrenia, and suggest that these are relevant to understanding broader aspects of pathophysiology, neurodevelopment, and neurodegeneration in this disorder. However, there are differences in findings which suggest that the effects of multiple variables on ERG and OCT data need further clarification. CONCLUSIONS The retina, as the only component of the CNS that can be imaged directly in live humans, has potential to clarify important aspects of schizophrenia. With greater attention to specific methodological issues, the true potential of ERG and OCT as biomarkers for important clinical phenomena in schizophrenia should become apparent.
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Pasmanter N, Petersen-Jones SM. A review of electroretinography waveforms and models and their application in the dog. Vet Ophthalmol 2020; 23:418-435. [PMID: 32196872 DOI: 10.1111/vop.12759] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 02/04/2023]
Abstract
Electroretinography (ERG) is a commonly used technique to study retinal function in both clinical and research ophthalmology. ERG responses can be divided into component waveforms, analysis of which can provide insight into the health and function of different types and populations of retinal cells. In dogs, ERG has been used in the characterization of normal retinal function, as well as the diagnosis of retinal diseases and measuring effects of treatment. While many components of the recorded waveform are similar across species, dogs have several notable features that should be differentiated from the responses in humans and other animals. Additionally, modifications of standard protocols, such as changing flash frequency and stimulus color, and mathematical models of ERG waveforms have been used in studies of human retinal function but have been infrequently applied to visual electrophysiology in dogs. This review provides an overview of the origins and applications of ERG in addition to potential avenues for further characterization of responses in the dog.
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Affiliation(s)
- Nathaniel Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
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Comparison Of Xenon And LED Light Sources In Electroretinography And Visual Evoked Potential Measurements. ANADOLU KLINIĞI TIP BILIMLERI DERGISI 2019. [DOI: 10.21673/anadoluklin.472427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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The effects of bandpass filtering on the oscillatory potentials of the electroretinogram. Doc Ophthalmol 2019; 138:247-254. [DOI: 10.1007/s10633-019-09683-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
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Hassankarimi H, Noori SMR, Jafarzadehpour E, Yazdani S, Radinmehr F. Analysis of pattern electroretinogram signals of early primary open-angle glaucoma in discrete wavelet transform coefficients domain. Int Ophthalmol 2019; 39:2373-2383. [PMID: 30725244 DOI: 10.1007/s10792-019-01077-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 01/25/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE To evaluate discrete wavelet transform coefficients and identify descriptors of pattern electroretinogram (PERG) waveforms in order to determine PERG characteristics for optimizing the diagnosis of early primary open-angle glaucoma (POAG). METHODS Pattern electroretinogram was performed in 30 normal eyes and 30 eyes with primary open-angle glaucoma according to the ISCEV protocol. The check size was 0.8° and 16°, and the color was black/white in both groups. The results were analyzed in time domain (TD) and discrete wavelet transform (DWT) using the MATLAB software. The mean value, standard deviation, and relative energy of level 6 and 7 detail coefficients (d6, d7) and level 7 approximation coefficients (a7) of Daubechies 4 (db4), Daubechies 8 (db8), Symlet 5 (sym5), Symlet 7 (sym7), and Coiflet 5 (coif5) wavelets were calculated. In all the mentioned wavelets, DWT descriptors were extracted. Signals were reconstructed by inverse DWT. All data obtained by TD and DWT analyses were compared between the two groups. RESULTS In both check sizes, a significant attenuation of N95 amplitude was seen in the patient group. The relative energy of a7 of db8 increased significantly in the POAG group in the 0.8° check size. In larger check stimuli, the relative energy of d7 of coif5 decreased significantly and the standard deviation of d7 of sym7 increased markedly in glaucomatous patients (P < 0.05). In small stimuli, N95 descriptor (7N) of db8 had the highest value and showed a significant increase as compared to the POAG group. In the 16° check size, there was no significant difference. A strong correlation was seen between reconstructed signals and originals (r = 0.99). CONCLUSION The DWT can quantify PERG responses more accurately. In agreement with TD and wavelet coefficients domain results, 7N of db8 decomposition can be used as a good indicator for early detection of POAG.
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Affiliation(s)
- Homa Hassankarimi
- Department of Medical Physics, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Seyed Mohammad Reza Noori
- Departments of Medical Physics and Biomedical Engineering, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ebrahim Jafarzadehpour
- Department of Optometry, School of Rehabilitation Science, Iran University of Medical Sciences, Tehran, Iran. .,Department of Optometry, Faculty of Rehabilitation, Iran University of Medical Sciences, Shahnazary St., Mohseni Sq., Mirdamad Blvd., Tehran, Iran.
| | - Shahin Yazdani
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Radinmehr
- Department of Optometry, School of Rehabilitation Science, Iran University of Medical Sciences, Tehran, Iran
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Gauvin M, Dorfman AL, Lachapelle P. Recording and Analysis of the Human Clinical Electroretinogram. Methods Mol Biol 2018; 1715:313-325. [PMID: 29188524 DOI: 10.1007/978-1-4939-7522-8_23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The electroretinogram (ERG) represents the biopotential that is produced by the retina in response to a light stimulus. To date, it remains the best diagnostic tool to objectively evaluate the functional integrity of the normal or diseased retina. In the following pages we briefly review the necessary requirements in order to record and analyze the conventional clinical ERG.
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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, 1001 Boul. Décarie, Glen Site, Block E, Montreal, QC, Canada, H4A 3J1
| | - Allison L Dorfman
- Department of Ophthalmology & Neurology-Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, 1001 Boul. Décarie, Glen Site, Block E, Montreal, QC, Canada, H4A 3J1
| | - Pierre Lachapelle
- Department of Ophthalmology & Neurology-Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, 1001 Boul. Décarie, Glen Site, Block E, Montreal, QC, Canada, H4A 3J1.
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Ebdali S, Hashemi B, Hashemi H, Jafarzadehpur E, Asgari S. Time and frequency components of ERG responses in retinitis pigmentosa. Int Ophthalmol 2017; 38:2435-2444. [PMID: 29189947 DOI: 10.1007/s10792-017-0748-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 10/10/2017] [Indexed: 12/01/2022]
Abstract
PURPOSE To evaluate the effects of retinitis pigmentosa (RP) on time, frequency, and time-frequency components of Xenon flash ERG signals using Fourier and wavelet transforms. METHODS Xenon flash ERG was done in 18 eyes of nine RP patients and 20 normal eyes. After examining latency and amplitude, Fourier and wavelet transforms were performed using MATLAB software. Then, we extracted the mode frequency from the Fourier transform and main frequencies and their occurrence time from the wavelet transform. Finally, mean differences were analyzed using statistical tests. RESULTS The results indicated increased latency and reduced ERG wave amplitude, no significant inter-group difference in the average mode frequency, and significant reduction in main signal frequencies and their increased occurrence times. Also one or two of the three main frequencies had disappeared in more advanced cases. CONCLUSION Retinitis pigmentosa can induce changes in ERG time and time-frequency components. Impacted areas can be identified more accurately by wavelet transform and converting scales to frequencies.
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Affiliation(s)
- Samira Ebdali
- Medical Physics Department, Faculty of Medical Sciences, Tarbiat Modares University, Jalal Ale Ahmad Highway, P.O. Box: 14115-111, Tehran, Iran
| | - Bijan Hashemi
- Medical Physics Department, Faculty of Medical Sciences, Tarbiat Modares University, Jalal Ale Ahmad Highway, P.O. Box: 14115-111, Tehran, Iran.
| | - Hassan Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | | | - Soheila Asgari
- Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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Dai J, He J, Wang G, Wang M, Li S, Yin ZQ. Contribution of GABAa, GABAc and glycine receptors to rat dark-adapted oscillatory potentials in the time and frequency domain. Oncotarget 2017; 8:77696-77709. [PMID: 29100418 PMCID: PMC5652335 DOI: 10.18632/oncotarget.20770] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/29/2017] [Indexed: 02/02/2023] Open
Abstract
Retinal oscillatory potentials (OPs) consist of a series of relatively high-frequency rhythmic wavelets, superimposed onto the ascending phase of the b-wave of the electroretinogram (ERG). However, the origin of OPs is uncertain and methods of measurement of OPs are diverse. In this study, we first isolated OPs from the rat ERG and fitted them with Gabor functions and found that the envelope of the OP contained information about maximum amplitude and time-to-peak to enable satisfactory quantification of the later OPs. And the OP/b-wave ratio should be evaluated to exclude an effect of the b-wave on the OPs. Next, we recorded OPs after intravitreal injection of 2-amino-4-phosphonobutyric acid (APB), tetrodotoxin (TTX), γ-aminobutyric acid (GABA), strychnine (STR), SR95531 (SR), isoguvacine (ISO), (1,2,5,6-tetrahydropyridin-4-yl) methylphosphinic acid (TPMPA) and GABA+TPMPA. We showed that GABA and APB only removed the later OPs, when compared to control eyes. TTX delayed the peak time, and STR, SR and ISO reduced the amplitude of OPs. TPMPA delayed the peak time but increased the ratio of OPs to b-wave. Furthermore, administration of combined GABA and TPMPA caused the later OPs to increase in amplitude with time, compared with those after delivery of GABA alone. Finally, we observed that GABAc and glycine receptors contributed to a low-frequency component of the OPs, while GABAa contributed to both components. These results suggest that the early components of the OPs are mainly generated by the photoreceptors, whilst the later components are mainly regulated by GABAa, GABAc and glycine receptors.
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Affiliation(s)
- Jiaman Dai
- College of Bioengineering, Chongqing University, Chongqing 400030, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China
| | - Juncai He
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Gang Wang
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Min Wang
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Shiying Li
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Zheng Qin Yin
- College of Bioengineering, Chongqing University, Chongqing 400030, China.,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400038, China.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
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Woo J, Jung S, Gauvin M, Lachapelle P. The DTL ERG electrode comes in different shapes and sizes: Are they all good? Doc Ophthalmol 2017; 135:155-164. [PMID: 28741115 DOI: 10.1007/s10633-017-9600-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/03/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE Although the DTL fiber electrode has been in use in the ERG field for more than four decades, its composition was never clearly defined. We compared five different types of conductive (DTL type) yarn (differing in terms of mass, number of filaments, and crimping degree) in order to determine whether we could identify one that would be better suited for the recording of ERGs. METHODS Photopic flash ERGs were recorded from five subjects using the following DTL electrodes: 27/7, 22/1, 11/1, 11/1*2, and 22/1*2. Data analysis included amplitude and peak time measurements of the a- and b-waves in the time domain (TD) as well as measurements of specific frequency descriptors of the ERG waveform in the time-frequency domain using the discrete wavelet transform (DWT) approach. The degree of comfortableness was also assessed in 12 subjects with two surveys (Likert 5-point and the ranking scale). RESULTS Comparisons of TD and DWT parameters did not permit to identify the best DTL electrode, all yielding comparable measures. There was a slight trend for the largest electrode (22/1*2) to yield the largest response, but this was at the expense of comfort, the 22/1*2 electrode being rated as the least comfortable. CONCLUSIONS Given the minimal impact the different electrodes had on the amplitude of the signal, we believe that comfort should dictate our choice. It would appear from our results that use of a multifilament electrode is the best choice since one can get an electrode whose size is optimized for the recording of large responses while minimizing the foreign-body sensation due to the small size of each of the filaments that compose this multifilament electrode.
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Affiliation(s)
- Jungeun Woo
- Departments of Ophthalmology and Neurology and Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, QC, Canada
| | - Suna Jung
- Departments of Ophthalmology and Neurology and Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, QC, Canada
| | - Mathieu Gauvin
- Departments of Ophthalmology and Neurology and Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, QC, Canada
| | - Pierre Lachapelle
- Departments of Ophthalmology and Neurology and Neurosurgery, Research Institute of the McGill University Health Centre/Montreal Children's Hospital, Montreal, QC, Canada. .,Department of Ophthalmology, Research Institute of the McGill University Health Centre, 1001 Decarie Boulevard, Glen Site, Block E, Room EM03238 (Program Mail Drop Point EM03211), Montreal, QC, H4A 3J1, Canada.
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Brandao LM, Monhart M, Schötzau A, Ledolter AA, Palmowski-Wolfe AM. Wavelet decomposition analysis in the two-flash multifocal ERG in early glaucoma: a comparison to ganglion cell analysis and visual field. Doc Ophthalmol 2017; 135:29-42. [PMID: 28593391 PMCID: PMC5532413 DOI: 10.1007/s10633-017-9593-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/23/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To further improve analysis of the two-flash multifocal electroretinogram (2F-mfERG) in glaucoma in regard to structure-function analysis, using discrete wavelet transform (DWT) analysis. METHODS Sixty subjects [35 controls and 25 primary open-angle glaucoma (POAG)] underwent 2F-mfERG. Responses were analyzed with the DWT. The DWT level that could best separate POAG from controls was compared to the root-mean-square (RMS) calculations previously used in the analysis of the 2F-mfERG. In a subgroup analysis, structure-function correlation was assessed between DWT, optical coherence tomography and automated perimetry (mf103 customized pattern) for the central 15°. RESULTS Frequency level 4 of the wavelet variance analysis (144 Hz, WVA-144) was most sensitive (p < 0.003). It correlated positively with RMS but had a better AUC. Positive relations were found between visual field, WVA-144 and GCIPL thickness. The highest predictive factor for glaucoma diagnostic was seen in the GCIPL, but this improved further by adding the mean sensitivity and WVA-144. CONCLUSIONS mfERG using WVA analysis improves glaucoma diagnosis, especially when combined with GCIPL and MS.
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Affiliation(s)
- Livia M Brandao
- Department of Ophthalmology, Basel University Hospital, Basel, BS, Switzerland.
- Universitätsspital Basel Augenklinik, Mittlere Strasse 91, 4031, Basel, Switzerland.
| | | | - Andreas Schötzau
- Department of Ophthalmology, Basel University Hospital, Basel, BS, Switzerland
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
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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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Assessing the Contribution of the Oscillatory Potentials to the Genesis of the Photopic ERG with the Discrete Wavelet Transform. BIOMED RESEARCH INTERNATIONAL 2016; 2016:2790194. [PMID: 28101507 PMCID: PMC5217158 DOI: 10.1155/2016/2790194] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/24/2016] [Accepted: 11/02/2016] [Indexed: 11/17/2022]
Abstract
The electroretinogram (ERG) is composed of slow (i.e., a-, b-waves) and fast (i.e., oscillatory potentials: OPs) components. OPs have been shown to be preferably affected in some diseases (such as diabetic retinopathy), while the a- and b-waves remain relatively intact. The purpose of this study was to determine the contribution of OPs to the building of the ERG and to examine whether a signal mostly composed of OPs could also exist. DWT analyses were performed on photopic ERGs (flash intensities: −2.23 to 2.64 log cd·s·m−2 in 21 steps) obtained from normal subjects (n = 40) and patients (n = 21) affected with a retinopathy. In controls, the %OP value (i.e., OPs energy/ERG energy) is stimulus- and amplitude-independent (range: 56.6–61.6%; CV = 6.3%). In contrast, the %OPs measured from the ERGs of our patients varied significantly more (range: 35.4%–89.2%; p < 0.05) depending on the pathology, some presenting with ERGs that are almost solely composed of OPs. In conclusion, patients may present with a wide range of %OP values. Findings herein also support the hypothesis that, in certain conditions, the photopic ERG can be mostly composed of high-frequency components.
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Kundra H, Park JC, McAnany JJ. Comparison of photopic negative response measurements in the time and time-frequency domains. Doc Ophthalmol 2016; 133:91-98. [PMID: 27562839 DOI: 10.1007/s10633-016-9558-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/15/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE To compare measurements of the full-field photopic negative response (PhNR), as well as intra-subject variation in the PhNR, using time and time-frequency domain analyses. METHODS Full-field ERGs were recorded from 20 normally sighted subjects (aged 24-65 years) elicited by a long-wavelength pulse (3 cd s m-2) presented against a short-wavelength adapting field (12.5 cd m-2). Three to 10 waveforms were obtained from each subject, and each waveform was analyzed using standard time domain analyses of the PhNR, as well as a discrete wavelet transform (DWT) to extract time-frequency components that correspond to the PhNR. Three different measures of the PhNR were derived and compared: (1) amplitude at the PhNR trough; (2) amplitude at 72 ms following stimulus onset; (3) energy in the 11 Hz, 60-120 ms DWT frequency bin that corresponds to the PhNR. In addition, the effect of normalizing the PhNR by the b-wave was evaluated for each of the measures. Coefficients of variation (CVs) were computed for each definition to evaluate intra-subject variation. RESULTS PhNR amplitudes measured at the trough and at 72 ms were significantly correlated (r = 0.88, p < 0.001). Additionally, PhNR energy derived by DWT was significantly correlated with the amplitude measured at the trough (r = 0.64, p = 0.002) and at 72 ms (r = 0.60, p = 0.005). Mean (±SD) intra-subject CVs were 26 % (15 %), 49 % (26 %), and 30 % (15 %), for measures at the trough, 72 ms, and DWT, respectively. Normalization by the b-wave amplitude (i.e., PhNR/b) had minimal effect on the intra-subject CVs, whereas normalization by the sum of the b-wave and PhNR amplitudes (i.e., PhNR/[b + PhNR]) substantially reduced the CVs for all three measures (mean CVs were less than 17 % for all conditions). CONCLUSIONS Although each PhNR definition has advantages and disadvantages, all three metrics provide similar estimates of the PhNR. Intra-subject CVs, however, were relatively high for measurements made at 72 ms, indicating that definitions based on a fixed time point may introduce variability. The substantial decrease in intra-subject variation after normalization by the sum of the PhNR and b-wave amplitudes may be advantageous under some conditions.
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Affiliation(s)
- Hansa Kundra
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., 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., Chicago, IL, 60612, USA
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1855 W. Taylor St., Chicago, IL, 60612, USA. .,Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan St., Chicago, IL, 60607, USA. .,Department of Psychology, University of Illinois at Chicago, 1007 W. Harrison St., Chicago, IL, 60612, USA.
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Witnessing the first sign of retinitis pigmentosa onset in the allegedly normal eye of a case of unilateral RP: a 30-year follow-up. Doc Ophthalmol 2016; 132:213-29. [PMID: 27041556 DOI: 10.1007/s10633-016-9537-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/28/2016] [Indexed: 10/22/2022]
Abstract
PURPOSE A patient initially presented with constricted visual field, attenuated retinal vasculature, pigmentary clumping and reduced ERG in OS only, suggestive of unilateral retinitis pigmentosa (RP). This patient was subsequently seen on eight occasions (over three decades), and, with time, the initially normal eye (OD) gradually showed signs of RP-like degeneration. The purpose of this study was to evaluate which clinical modality (visual field, funduscopy or electroretinography) could have first predicted this fate. METHODS At each time points, data obtained from our patient were compared to normative data using Z tests. RESULTS At initial visit, all tests were significantly (p < 0.05) altered in OS and normal in OD. Visual field and retinal vessel diameter in OD reduced gradually to reach statistical significance at the 5th visit and 6th visit (21 and 22 years after the first examination, respectively). In OD, the amplitude of the scotopic and photopic ERGs reduced gradually and was significantly smaller than normal at the 2nd visit (after 11 years) and 3rd visit (after 18 years), respectively. When the photopic ERG was analyzed using the discrete wavelet transform (DWT), we were able to detect a significant change at the 2nd visit (after 11 years) instead of the 3rd visit (18 years). CONCLUSIONS Our study allowed us to witness the earliest manifestation of an RP disease process. The ERG was the first test to detect significant RP changes. A significantly earlier detection of ERG anomalies was obtained when the DWT was used, demonstrating its advantage for early detection of ERG changes.
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