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Daich Varela M, Laich Y, Hashem SA, Mahroo OA, Webster AR, Michaelides M. Prognostication in Stargardt Disease Using Fundus Autofluorescence: Improving Patient Care. Ophthalmology 2023; 130:1182-1190. [PMID: 37331482 PMCID: PMC11108789 DOI: 10.1016/j.ophtha.2023.06.010] [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: 03/06/2023] [Revised: 05/22/2023] [Accepted: 06/06/2023] [Indexed: 06/20/2023] Open
Abstract
PURPOSE To explore fundus autofluorescence (FAF) imaging as an alternative to electroretinography as a noninvasive, quick, and readily interpretable method to predict disease progression in Stargardt disease (STGD). DESIGN Retrospective case series of patients who attended Moorfields Eye Hospital (London, United Kingdom). PARTICIPANTS Patients with STGD who met the following criteria were included: (1) biallelic disease-causing variants in ABCA4, (2) electroretinography testing performed in house with an unequivocal electroretinography group classification, and (3) ultrawidefield (UWF) FAF imaging performed up to 2 years before or after the electroretinography. METHODS Patients were divided into 3 electroretinography groups based on retinal function and 3 FAF groups according to the extent of hypoautofluorescence and retinal background appearance. Fundus autofluorescence images of 30° and 55° were reviewed subsequently. MAIN OUTCOME MEASURES Electroretinography and FAF concordance and its association with baseline visual acuity (VA) and genetics. RESULTS Two hundred thirty-four patients were included in the cohort. One hundred seventy patients (73%) were in electroretinography and FAF groups of the same severity, 33 (14%) were in a milder FAF than electroretinography group, and 31 (13%) were in a more severe FAF than electroretinography group. Children < 10 years of age (n = 23) showed the lowest electroretinography and FAF concordance at 57% (9 of the 10 with discordant electroretinography and FAF showed milder FAF than electroretinography), and adults with adult onset showed the highest (80%). In 97% and 98% of patients, 30° and 55° FAF imaging, respectively, matched with the group defined by UWF FAF. CONCLUSIONS We demonstrated that FAF imaging is an effective method to determine the extent of retinal involvement and thereby inform prognostication by comparing FAF with the current gold standard of electroretinography. In 80% of patients in our large molecularly proven cohort, we were able to predict if the disease was confined to the macula or also affected the peripheral retina. Children assessed at a young age, with at least 1 null variant, early disease onset, poor initial VA, or a combination thereof may have wider retinal involvement than predicted by FAF alone, may progress to a more severe FAF phenotype over time, or both. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Yannik Laich
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Shaima Awadh Hashem
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Tian AL, Wu Q, Liu P, Zhao L, Martins I, Kepp O, Leduc M, Kroemer G. Lysosomotropic agents including azithromycin, chloroquine and hydroxychloroquine activate the integrated stress response. Cell Death Dis 2021; 12:6. [PMID: 33414432 PMCID: PMC7790317 DOI: 10.1038/s41419-020-03324-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/01/2020] [Accepted: 12/04/2020] [Indexed: 12/15/2022]
Abstract
The integrated stress response manifests with the phosphorylation of eukaryotic initiation factor 2α (eIF2α) on serine residue 51 and plays a major role in the adaptation of cells to endoplasmic reticulum stress in the initiation of autophagy and in the ignition of immune responses. Here, we report that lysosomotropic agents, including azithromycin, chloroquine, and hydroxychloroquine, can trigger eIF2α phosphorylation in vitro (in cultured human cells) and, as validated for hydroxychloroquine, in vivo (in mice). Cells bearing a non-phosphorylatable eIF2α mutant (S51A) failed to accumulate autophagic puncta in response to azithromycin, chloroquine, and hydroxychloroquine. Conversely, two inhibitors of eIF2α dephosphorylation, nelfinavir and salubrinal, enhanced the induction of such autophagic puncta. Altogether, these results point to the unexpected capacity of azithromycin, chloroquine, and hydroxychloroquine to elicit the integrated stress response.
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Affiliation(s)
- Ai-Ling Tian
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
| | - Qi Wu
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
- Department of Breast and Thyroid Surgery, Renmin Hospital of Wuhan University, Wuhan, Hubei, P. R. China
| | - Peng Liu
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
| | - Liwei Zhao
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
| | - Isabelle Martins
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
| | - Oliver Kepp
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France.
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France.
| | - Marion Leduc
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France
| | - Guido Kroemer
- Centre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France.
- Metabolomics and Cell Biology Platforms, Gustave Roussy, Villejuif, France.
- Suzhou Institute for Systems Medicine, Chinese Academy of Medical Sciences, Suzhou, China.
- Pôle de Biologie, Hôpital Européen Georges Pompidou, AP-HP, Paris, France.
- Karolinska Institutet, Department of Women's and Children's Health, Karolinska University Hospital, Stockholm, Sweden.
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Abstract
PURPOSE To evaluate the ability of macular and multifocal (mf) pattern electroretinogram (PERG) to differentiate preperimetric glaucoma (PG) and glaucoma with hemifield loss (GHL) from controls, to compare the discrimination ability of PERG and fourier-domain optical coherence tomography (FD-OCT), and to assess the relationship between measurements. PATIENTS AND METHODS Standard automated perimetry, steady-state and transient PERG and mfPERG measurements were obtained from PG (n=14, 24 eyes), GHL (n=5, 7 eyes), and controls (n=19, 22 eyes). Circumpapillary retinal nerve fiber layer (cpRNFL), full-thickness macula, and segmented macular layer thicknesses on FD-OCT were investigated. Measurements were compared using mixed effects linear models. The relationships between measurements and the diagnostic performance of each technology were assessed. RESULTS Compared with controls, average P50 peak time transient PERG responses were reduced in PG and GHL, whereas average latency and amplitude steady-state and mfPERG responses were abnormal only in GHL. cpRNFL and macular thickness measurements in PG and GHL differed significantly from controls. A significant relationship was found between PERG and most FD-OCT or SAP parameters. Partial least squares discriminant analysis revealed that OCT parameters, along with mfPERG and transient PERG parameters had similar ability to discriminate PG and GHL from healthy controls. CONCLUSIONS PERG and OCT parameters may be abnormal, with significant correlations between measurements, in PG eyes. Both technologies may be useful for detection of early glaucoma.
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Repeatability of pattern electroretinogram measurements using a new paradigm optimized for glaucoma detection. J Glaucoma 2009; 18:437-42. [PMID: 19680050 DOI: 10.1097/ijg.0b013e31818c6f44] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the within-trial and between-trial repeatability of pattern electroretinogram (PERG) measurements in healthy and patient eyes, using a new clinical instrument, the PERGLA. STUDY DESIGN In all, 70 eyes of 35 healthy individuals (intraocular pressure <22 mm Hg, healthy optic disc by stereophotograph assessment, standard visual fields within normal limits) and 90 eyes of 45 clinic patients (ocular hypertensive, glaucomatous optic neuropathy by stereophotograph assessment and/or repeatable abnormal visual fields) enrolled in the University of California, San Diego Diagnostic Innovations in Glaucoma Study (DIGS) were evaluated. Average mean deviation of patient eyes on standard automated perimetry was -1.81 dB (SD=2.61). METHODS The PERG was recorded using the PERGLA paradigm from both eyes simultaneously twice (ie, 2 trials) by a single operator with electrodes being removed and reattached between recordings. Repeatability of PERG amplitude (microV) and phase (pi rad) between 2 runs within a single trial (within-trial condition) was compared with repeatability between 2 trials (ie, after electrode replacement, between-trial condition) by calculating the coefficients of variability (CVs) and the intraclass correlation coefficients (ICCs) and displaying Bland-Altman plots. RESULTS For healthy eyes, amplitude CVs (SD) were 11.5% (11.5) and 9.9% (0.79) for within-trial and between-trial conditions, respectively. ICCs were 0.91 and 0.85. Phase CVs were 1.3% (1.5) (within-trials) and 1.5% (1.4) (between-trials) and ICCs were 0.85 and 0.88. For patient eyes, amplitude CVs (SD) were 12.2% (10.1) and 11.2% (7.5) for within-trial and between-trial conditions, respectively. ICCs were 0.92 and 0.89. Phase CVs were 2.2% (2.2) (within-trials) and 2.4% (2.2) (between-trials) and ICCs were 0.82 and 0.83. Bland-Altman plots indicated good agreement between the repeated recordings and were similar within-trials and between-trials for healthy and patient eyes. CONCLUSIONS Repeatability of PERGLA recordings is good and is similar within-trials and between-trials for both healthy and patient eyes suggesting this technique is promising for monitoring change over time.
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Fredette MJ, Anderson DR, Porciatti V, Feuer W. Reproducibility of pattern electroretinogram in glaucoma patients with a range of severity of disease with the new glaucoma paradigm. Ophthalmology 2008; 115:957-63. [PMID: 17976726 PMCID: PMC2710310 DOI: 10.1016/j.ophtha.2007.08.023] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 07/31/2007] [Accepted: 08/10/2007] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To determine the reproducibility of the pattern electroretinogram with the new Pattern Electroretinogram for Glaucoma (PERGLA) recording paradigm in glaucoma patients with a range of severity. DESIGN Experimental study. PARTICIPANTS Fifty-three glaucoma patients were recruited for the study (mean age +/- standard deviation [SD], 69+/-11 years). Their mean deviation (MD) global indices on static automatic perimetry ranged from 2.16 to -31.36 decibels (mean MD, -9.05). INTERVENTION All patients had pattern electroretinogram recordings done 5 times by the same operator, on 5 different days with the standardized PERGLA paradigm. MAIN OUTCOME MEASURES Pattern electroretinogram amplitude (microvolts), phase (pi radians), response variability (coefficient of variation [CV] = SD/mean x 100) of amplitude and phase of 2 partial averages that build up the pattern electroretinogram waveform, interocular asymmetry in amplitude and phase (in terms of the CV generated by the pattern electroretinogram software), signal-to-noise (S/N) ratio, SDs, CV, and intraclass correlation coefficient (ICC). All analyses were done on one eye of each subject, except when interocular asymmetry was studied. RESULTS The CVs of intrasession variabilities in amplitude and phase were 12.08% and 2.20%, respectively, and those of intersession variabilities were 20.82% and 4.17%. The pattern electroretinogram produced intersession ICCs in amplitude and phase of 0.791 and 0.765, respectively. These ICCs were significantly higher than the ICCs for pattern electroretinogram interocular asymmetry in amplitude and phase (0.659 [P<0.05] and 0.571 [P<0.05], respectively). On average, the pattern electroretinogram S/N ratio in glaucomatous patients was about 5:1. CONCLUSIONS The reproducibility of PERGLA in glaucomatous patients is sufficiently good for it to be considered a useful complementary clinical tool. Being more reproducible, direct measures of amplitude and phase should be more useful in monitoring progression than interocular asymmetry comparisons.
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Affiliation(s)
- Marie-Josée Fredette
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, Florida, USA.
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da Costa GM, dos Anjos LM, Souza GS, Gomes BD, Saito CA, Pinheiro MDCN, Ventura DF, da Silva Filho M, Silveira LCL. Mercury toxicity in Amazon gold miners: visual dysfunction assessed by retinal and cortical electrophysiology. ENVIRONMENTAL RESEARCH 2008; 107:98-107. [PMID: 17889848 DOI: 10.1016/j.envres.2007.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Revised: 06/28/2007] [Accepted: 08/03/2007] [Indexed: 05/17/2023]
Abstract
Amazonian gold mining activity results in human exposure to mercury vapor. We evaluated the visual system of two Amazonian gold miners (29 and 37 years old) by recording the transient pattern electroretinogram (tPERG) and transient pattern visual evoked potential (tPVEP). We compared these results with those obtained from a regional group of control subjects. For both tPERG and tPVEP, checkerboards with 0.5 or 2 cycles per degree (cpd) of spatial frequency were presented in a 16 degrees squared area, 100% Michelson contrast, 50cd/m2 mean luminance, and 1 Hz square-wave pattern-reversal presentation. Two averaged waveforms (n=240 sweeps, 1s each) were monocularly obtained for each subject in each condition. Both eyes were monocularly tested only in gold miners. Normative data were calculated using a final pooled waveform with 480 sweeps. The first gold miner, LCS, had normal tPERG responses. The second one, RNP, showed low tPERG (P50 component) amplitudes at 0.5 cpd for both eyes, outside the normative data, and absence of response at 2 cpd for his right eye. Delayed tPVEP responses (P100 component) were found at 2 cpd for LCS but the implicit times were inside the normative data. Subject RNP also showed delayed tPVEP responses (all components), but only the implicit time obtained with his right eye was outside the normative data at 2 cpd. We conclude that mercury exposure levels found in the Amazon gold miners is high enough to damage the visual system and can be assessed by non-invasive electrophysiological techniques.
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Affiliation(s)
- Genilma M da Costa
- Departamento de Fisiologia, Universidade Federal do Pará, Belém, Pará, Brazil
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Cunha LP, Oyamada MK, Monteiro MLR. Pattern electroretinograms for the detection of neural loss in patients with permanent temporal visual field defect from chiasmal compression. Doc Ophthalmol 2008; 117:223-32. [PMID: 18401605 DOI: 10.1007/s10633-008-9126-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 03/25/2008] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the ability of full-field and hemifield pattern electroretinogram (PERG) parameters to differentiate between healthy eyes and eyes with band atrophy (BA) of the optic nerve. METHODS Twenty-six eyes from 26 consecutive patients with permanent temporal hemianopic visual field defects and BA of the optic nerve from previous chiasmal compression and 26 healthy subjects were studied prospectively. All patients were submitted to an ophthalmic examination including Humphrey 24-2 SITA Standard automated perimetry. Full-field and hemifield (nasal and temporal) stimulation transient pattern electroretinograms (PERG) were recorded using checkerboard screens. Amplitudes and peak times for the P50 and N95 as well as the overall P50+N95 amplitude were measured. The intraocular N95:P50 amplitude ratio was calculated. Comparisons were made using Student's t-test. Receiver operating characteristic (ROC) curves were used to describe the ability of PERG parameters to discriminate the groups. RESULTS Full-field P50, N95, and P50+N95 amplitude values were significantly smaller in eyes with BA than in control eyes (P < 0.001). Nasal and temporal hemifield PERG studies revealed significant differences in N95 and P50+N95 amplitudes measurements. No significant difference was observed regarding peak times or N95:P50 amplitude ratios. Nasal and temporal hemifield PERG values did not differ significantly in eyes with BA or in controls. Using the 10th percentile of normals as the lower limit of normal, 16 of 26 eyes were considered abnormal according to the best discriminating parameters. CONCLUSIONS Transient PERG amplitude measurements were efficient at differentiating eyes with BA and permanent visual field defects from normal controls. Hemifield stimulation PERG parameters were unable to detect asymmetric hemifield neural loss, but further studies are required to clarify this issue.
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Affiliation(s)
- Leonardo P Cunha
- Division of Ophthalmology, Hospital das Clínicas of the University of São Paulo Medical School, Sao Paulo, Brazil
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Porciatti V, Saleh M, Nagaraju M. The pattern electroretinogram as a tool to monitor progressive retinal ganglion cell dysfunction in the DBA/2J mouse model of glaucoma. Invest Ophthalmol Vis Sci 2007; 48:745-51. [PMID: 17251473 PMCID: PMC1794678 DOI: 10.1167/iovs.06-0733] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the baseline characteristics, reliability, and dynamic range of the pattern electroretinogram (PERG) as a tool to monitor progressive RGC dysfunction in the DBA/2J mouse model of glaucoma with spontaneously elevated intraocular pressure (IOP). METHODS PERGs were recorded from 56 undilated eyes of 28 anesthetized (ketamine-xylazine-acepromazine) DBA/2J mice of different ages (2-4 months, n = 44 eyes; 12-14 months, n = 12 eyes) in response to contrast reversal of gratings that maximize PERG amplitude (95% contrast, 1-Hz reversal, 0.05 cyc/deg spatial frequency, 50 degrees x 56 degrees field size). Robust averaging (1800 sweeps) was used to isolate PERG from background noise. Cone-driven ERGs in response to diffuse light flashes superimposed on a rod-adapting background (FERG) were also recorded. RESULTS PERGs had consistent waveforms and were reproducible across batches of mice and operators. In 2- to 4-month-old mice (prehypertensive stage), the PERG amplitude (mean, 8.15 +/- 0.4 microV [SEM]) was considerably larger than the noise (mean 1.18 +/- 0.1 microV). The test-retest variability (two different sessions 1 week apart) and interocular asymmetry of PERG amplitude was approximately 30%, and that of PERG latency was approximately 17%. In 12- to 14-month-old mice (advanced hypertensive stage) the PERG amplitude (mean, 1.29 +/- 0.12 microV) was close to that of noise. In 12- to 14-month-old mice the FERG was reduced to a lesser extent compared with the PERG. CONCLUSIONS The PERG has an adequate signal-to-noise ratio, reproducibility, and dynamic range to monitor the progression of functional changes in the inner retina in DBA/2J mice.
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Affiliation(s)
- Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
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Ventura LM, Porciatti V, Ishida K, Feuer WJ, Parrish RK. Pattern electroretinogram abnormality and glaucoma. Ophthalmology 2005; 112:10-9. [PMID: 15629814 PMCID: PMC2756427 DOI: 10.1016/j.ophtha.2004.07.018] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Accepted: 07/19/2004] [Indexed: 10/26/2022] Open
Abstract
PURPOSE To determine the existence of retinal ganglion cell dysfunction and associated risk factors in glaucoma suspects with increased optic disc cupping and normal visual field. DESIGN Cross-sectional, observational study. PARTICIPANTS Two hundred glaucoma suspect (GS) patients were identified based on optic disc abnormalities (vertical cup-to-disc ratios [C/D]>0.5; vertical C/D asymmetry >or= 0.2; disc hemorrhages; notching) in association with known glaucoma risk factors (positive family history, African American descent, increased intraocular pressure [IOP]), but normal visual fields. Forty-two patients had early manifest glaucoma (EMG). Sixteen normal black subjects were added to update previous pattern electroretinogram (PERG) normative data and to establish a normal control (NC) group with a racial breakdown comparable with that of the study groups. METHODS Pattern electroretinograms were recorded simultaneously from both eyes using skin electrodes and automated analysis; visual fields were monitored with standard white-on-white automated perimetry (SAP) central 24-2 program; vertical C/D was evaluated by an independent reader from stereo disc photographs; and univariate and multivariate statistical analysis between PERG and other outcome measures was evaluated. MAIN OUTCOME MEASURES Pattern electroretinogram amplitude (microV), phase (pi rad), and interocular asymmetry in amplitude and phase (%); and SAP mean deviation (MD; decibels), vertical C/D, age (years), IOP (mmHg), and race (black vs. nonblack). RESULTS The PERG results were abnormal in at least 1 of the outcome measures in 52% of GS patients and 69% of EMG patients. The PERG amplitude was correlated weakly with both MD (P<0.01) and vertical C/D (P = 0.05). The correlation between PERG amplitude and MD and C/D was stronger (P<0.001) for interocular differences rather than absolute measures. Interocular PERG amplitude asymmetry increased with severity of disease (EMG>GS>NC; P<0.01). The PERG amplitude decline with age was steeper in patients with a more negative MD (P<0.01) and in patients with a more negative MD and a larger vertical C/D (P = 0.06). Black race (but not family history) was associated with lower PERG amplitude (P = 0.005) in GS and EMG patients, but not in normal controls (P = 0.44). CONCLUSIONS The correlation between PERG abnormality and known risk factors for glaucoma indicates that PERG has a predictive potential for the development or progression of the disease, or both.
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Porciatti V, Ventura LM. Normative data for a user-friendly paradigm for pattern electroretinogram recording. Ophthalmology 2004; 111:161-8. [PMID: 14711729 PMCID: PMC2760457 DOI: 10.1016/j.ophtha.2003.04.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2003] [Accepted: 04/11/2003] [Indexed: 11/22/2022] Open
Abstract
PURPOSE To provide normative data for a user-friendly paradigm for the pattern electroretinogram (PERG) optimized for glaucoma screening (PERGLA). DESIGN Prospective nonrandomized case series. PARTICIPANTS Ninety-three normal subjects ranging in age between 22 and 85 years. METHODS A circular black-white grating of 25 degrees visual angle, reversing 16.28 times per second, was presented on a television monitor placed inside a Ganzfeld bowl. The PERG was recorded simultaneously from both eyes with undilated pupils by means of skin cup electrodes taped over the lower eyelids. Reference electrodes were taped on the ipsilateral temples. Electrophysiologic signals were conventionally amplified, filtered, and digitized. Six hundred artifact-free repetitions were averaged. The response component at the reversal frequency was isolated automatically by digital Fourier transforms and was expressed as a deviation from the age-corrected average. The procedure took approximately 4 minutes. MAIN OUTCOME MEASURES Pattern electroretinogram amplitude ( micro V) and phase (pi rad); response variability (coefficient of variation [CV] = standard deviation [SD] / mean x 100) of amplitude and phase of 2 partial averages that build up the PERG waveform; amplitude ( micro V) of background noise waveform, obtained by multiplying alternate sweeps by +1 and -1; and interocular asymmetry (CV of amplitude and phase of the PERG of the 2 eyes). RESULTS On average, the PERG has a signal-to-noise ratio of more than 13:1. The CVs of intrasession and intersession variabilities in amplitude and phase are lower than 10% and 2%, respectively, and do not depend on the operator. The CV of interocular asymmetries in amplitude and phase are 9.8+/-8.8% and 1.5+/-1.4%, respectively. The PERG amplitude and phase decrease with age. Residuals of linear regression lines have normal distribution, with an SD of 0.1 log units for amplitude and 0.019 log units for phase. Age-corrected confidence limits (P<0.05) are defined as +/-2 SD of residuals. CONCLUSIONS The PERGLA paradigm yields responses as reliable as the best previously reported using standard protocols. The ease of execution and interpretation of results of PERGLA indicate a potential value for objective screening and follow-up of glaucoma.
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Bui BV, Fortune B, Cull G, Wang L, Cioffi GA. Baseline characteristics of the transient pattern electroretinogram in non-human primates: inter-ocular and inter-session variability. Exp Eye Res 2003; 77:555-66. [PMID: 14550397 DOI: 10.1016/s0014-4835(03)00195-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This study assessed the inter-ocular and inter-session variability of the transient pattern electroretinogram (PERG) in a group of non-human primates. The transient PERG was measured both eyes of 29 non-human primates, and again after three months in 23 eyes of 23 of these animals. Signals were elicited using a contrast (90%, 75 cdm(-2)) reversing (5 reversals sec(-1)) checkerboard pattern (0.56 cpd). PERGs were also measured for stimuli of varied spatial frequency (n=8, 0.07-2.22 cpd), contrast (n=4, 20-100%), mean luminance (n=4, 4.7-75 cdm(-2)) and defocus (n=5, +1, +2, +3 diopters). The inter-eye and inter-session limits-of-agreement (LOA; 95%) were determined for each PERG parameter. Variability was also compared with previous studies using the coefficient-of-variability (COV). Pharmacological blockade of the inner retinal contributions to the PERG measured under these conditions was conducted in one animal using intravitreal injection of tetrodotoxin (approximately 6 microM) and N-methyl-D-aspartic acid (approximately 6 microM). The N95 component of the primate transient PERG showed spatial tuning, with a peak between 0.14 and 0.28cpd. This spatial tuning was not as apparent for the P50 component. A linear relationship between P50 and N95 amplitude was found with contrast and mean luminance. Both components were attenuated with the introduction of +2 diopters or more of defocus. The inter-session COV for the P50 and N95 components were 23.8 and 19.2%, respectively, while the LOA were 58 and 46%, respectively. The N95:P50 ratio had smaller inter-session variability, was robust to changes in contrast, mean luminance and defocus, and was effective for characterization of inner-retinal dysfunction after pharmacologic block.
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Affiliation(s)
- B V Bui
- Discoveries In Sight, Legacy Clinical Research and Technology Center, Portland, OR 97208-3950, USA
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Bayer AU, Maag KP, Erb C. Detection of optic neuropathy in glaucomatous eyes with normal standard visual fields using a test battery of short-wavelength automated perimetry and pattern electroretinography. Ophthalmology 2002; 109:1350-61. [PMID: 12093662 DOI: 10.1016/s0161-6420(02)01100-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
PURPOSE To evaluate the clinical use of a test battery of short-wavelength automated perimetry (SWAP), frequency-doubling technology (FDT) perimetry, and pattern-electroretinography (PERG) in patients with definite primary open-angle glaucoma (POAG) but normal results on standard automated perimetry (SAP). STUDY DESIGN Prospective, comparative, observational case series. PARTICIPANTS Thirty-six patients with POAG with standard visual field defects in one eye and normal standard visual fields in the contralateral eye and 36 normal controls were enrolled. MAIN OUTCOME MEASURES SWAP, PERG, FDT, and SAP were performed in all eyes, and global indices and amplitudes were used for statistical analysis. RESULTS When contralateral POAG eyes with asymmetric glaucomatous damage was compared, a paired t test showed significant differences in SAP mean deviation (MD) (P < 0.0001), SWAP-MD (P = 0.0003), FDT-MD (P = 0.0008), and PERG amplitudes (P < 0.0001). When comparing between POAG eyes with normal results on SAP and normal controls, Student's t test showed significant differences for SWAP-MD (P < 0.0001), FDT-MD (P = 0.0006), PERG N1P1-amplitude (P = 0.0486) and P1N2-amplitude (P < 0.0001); receiver operating characteristic analysis revealed promising accuracy for SWAP-MD of 73.6% (P < 0.0001). SWAP-MD (P < 0.0001) and FDT-MD (P < 0.0001) correlated significantly with SAP-MD and with each other (range, P < 0.0001 to P = 0.0020). Regression analysis revealed that PERG P1N2-amplitude could improve the power of SWAP-MD from 73.6% to detect early POAG in eyes with normal results on SAP to an accuracy of 81.9%. CONCLUSIONS A test battery of SWAP-MD and PERG P1N2-amplitude could detect glaucomatous optic neuropathy in POAG eyes with normal standard visual fields, whereas FDT-MD and SWAP-MD significantly correlated with each other and with SAP-MD. All tests were able to detect the eye with the more severe glaucomatous optic neuropathy in patients with asymmetric POAG.
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Affiliation(s)
- Andreas U Bayer
- Department of Ophthalmology, Hospital of Weilheim-Schongau, Puetrichstrasse 32, 82362 Weilheim, Germany
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Smelson DA, Roy A, Roy M, Tershakovec D, Engelhart C, Losonczy MF. Electroretinogram and cue-elicited craving in withdrawn cocaine-dependent patients: a replication. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2001; 27:391-7. [PMID: 11417946 DOI: 10.1081/ada-100103716] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND We previously reported that cocaine-dependent patients with a reduced blue cone b wave electroretinogram (ERG) responses had significantly more cue-elicited craving. METHODS A new series of 21 recently withdrawn cocaine-dependent patients completed a craving questionnaire at baseline and following cue exposure; an ERG was also performed. RESULTS Cocaine-dependent patients with a blunted ERG blue cone response (<0.5 microV) showed greater increases in craving following cue exposure. When subjects were included from our preliminary study (N = 14), these differences became highly significant. CONCLUSIONS Patients with a reduced ERG response may represent a subgroup more vulnerable to cocaine craving and future relapse.
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Affiliation(s)
- D A Smelson
- Department of Veterans Affairs, New Jersey Health Care System, Lyons 07939-5000, USA
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Holder GE. The pattern electroretinogram in anterior visual pathway dysfunction and its relationship to the pattern visual evoked potential: a personal clinical review of 743 eyes. Eye (Lond) 1998; 11 ( Pt 6):924-34. [PMID: 9537157 DOI: 10.1038/eye.1997.231] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The pattern electroretinogram (PERG) has now been in routine clinical use for sufficiently long to allow a personal clinical review of its relationship to the cortically generated pattern visual evoked potential (PVEP). The PERG and PVEP findings are presented from 520 eyes with optic nerve demyelination (382 eyes), optic nerve compression (90 eyes) or heredofamilial optic atrophy (48 eyes), and these are compared with the findings obtained in 223 eyes with dysfunction anterior to the retinal ganglion cells. Dysfunction anterior to the retinal ganglion cells gives a reduction in the P50 component of the PERG, but this component is usually spared in optic nerve disease where selective loss of the N95 component is by far the most frequently occurring abnormality. A diagnostic strategy is presented.
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Affiliation(s)
- G E Holder
- Department of Clinical Neurophysiology, King's College Hospital, London, UK
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Otto T, Bach M. Retest variability and diurnal effects in the pattern electroretinogram. Doc Ophthalmol 1998; 92:311-23. [PMID: 9476598 DOI: 10.1007/bf02584085] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pattern electroretinograms were recorded to phase-reversing checkerboard stimuli with DTL electrodes under conditions close to those of the ISCEV pattern electroretinogram guidelines. Both transient (2 reversals/s) and steady-state (16 reversals/s) stimulation was used. The check sizes were 0.4 degree, 0.8 degree and 16 degrees; the mean luminance 45 cd/m2, the contrast 98%, and the field size 32 degrees x 27 degrees. In 42 eyes of 21 subjects, measurements were repeated at the same time of day after 1 week. For each eye, the intersession coefficient of variation was calculated as a measure of reproducibility. We found a coefficient of variation (+/- standard deviation) of 7% +/- 5% for the amplitude of the steady-state pattern electroretinogram, 9.5% +/- 7% for the transient pattern electroretinogram and 1.5% +/- 2% for the latency of the transient pattern electroretinogram. To assess the diurnal variability, during a 15-h period, three pattern electroretinograms were recorded in 10 subjects. No relationship was found between the P50 latency and the time of day. However, the mean amplitude showed a maximum in the morning (9:30 am) and a minimum in the afternoon (2:30 pm). This small effect (about 7%, p < 0.001) was more pronounced for N95 and steady-state amplitudes than for P50 amplitudes (p < 0.01). Diurnal contributions to the pattern electroretinogram ranged between 3% and 10%. We conclude that pattern electroretinogram amplitude reproduces within +/- 10% with a probability of 70%. The effect size of the diurnal variation is similar and might be relevant for longitudinal studies.
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Affiliation(s)
- T Otto
- Universitäts-Augenklinik, Freiburg, Germany
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16
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Graham SL, Klistorner A. Electrophysiology: A review of signal origins and applications to investigating glaucoma. ACTA ACUST UNITED AC 1998. [DOI: 10.1111/j.1442-9071.1998.tb01446.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Tilanus MA, Cuypers MH, Bemelmans NA, Pinckers AJ. Prognostic value of pattern reversal visual-evoked potentials in idiopathic epiretinal membrane. Graefes Arch Clin Exp Ophthalmol 1997; 235:474-9. [PMID: 9285214 DOI: 10.1007/bf00947002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Prognostically favorable factors for epiretinal membrane removal have been described in the literature by several authors. Little information, however, is available about the objective assessment of the preoperative macular function. This study reports the results of idiopathic epiretinal membrane removal and the prognostic value of preoperative, pattern reversal visual-evoked potentials (PRVEPS) in recovery of visual acuity (VA). METHODS In 60 patients (60 eyes) with idiopathic epiretinal membrane we performed PRVEP examination preoperatively. All eyes were operated on by standard three-port vitrectomy with membrane removal. Two eyes were excluded because of postoperative complications. Follow-up VA was compared with preoperative VA for the 58 study eyes and correlated with preoperative PRVEP parameters. RESULTS The mean preoperative VA was 0.2, the mean postoperative VA, 0.4. The PRVEP was recordable in 74%, 67% and 36% of cases for check sizes of 17, 10 and 7 arcmin respectively. Twenty patients (50%) had an increase in VA of two lines or more, in 25 patients (43%) VA remained within one line of the preoperative value, and in 4 patients (7%) VA decreased by two lines or more. The mean preoperative VA was not significantly different between the group with an improved VA and the group that did not benefit from membrane removal. Of the PRVEP parameters, only the N80 latency for the 17' check size was significantly associated with postoperative visual outcome. CONCLUSION The PRVEP is applicable as a predictor for visual outcome in cases of epiretinal membrane removal. For the 17' pattern size we found a significant association of the combination of recordability and delayed N80 latency with visual outcome.
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Affiliation(s)
- M A Tilanus
- Institute of Ophthalmology, University Hospital Nijmegen, The Netherlands
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18
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Abstract
Conventional visual field testing, with a uniform white-on-white stimulus, is used routinely to diagnose and follow patients with chronic open-angle glaucoma. Many investigators, however, believe that conventional perimetry may not detect the earliest visual dysfunction in patients with chronic open-angle glaucoma. Consequently, much research has been performed over the past decade to develop a visual function test which might diagnose chronic open-angle glaucoma earlier than conventional perimetry. This review discusses the mechanisms, clinical studies and the current usefulness of the most common new visual function techniques. These tests attempt to detect early glaucomatous visual loss, generally by placing the visual system under stress and by minimizing the influence of extensive functional redundancy in the retinal ganglion cell network due to widely overlapping receptive fields. Success of new visual function tests depends on the specificity and the sensitivity of the instrument, excellent patient acceptance, short test duration, standardization of techniques, and limited expense. In addition to searching for newer visual function tests to evaluate glaucoma, we should continue efforts to improve the diagnostic capability and shorten the test duration of conventional perimetry.
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Affiliation(s)
- W C Stewart
- Department of Ophthalmology, Medical University of South Carolina, Charleston, USA
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Abstract
Electrodiagnostic examination of the visual system includes visual evoked potentials and electroretinography. These tests can be applied to all ages. Pitfalls in the clinical ophthalmologic examination of children, such as optic nerve pallor and pigmentary retinopathy, can be clarified by these tests. Investigation of neurodegenerative disease may be directed to the most likely defect by results of visual evoked potential testing and electroretinography. The child who is unable to meaningfully communicate sensory experience can be objectively evaluated by these studies. Familiarity with the applications and limitations of these tests will allow the examiner to choose the appropriate setting and time to apply each of them.
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Affiliation(s)
- R S Baker
- Department of Ophthalmology, University of Kentucky Medical Center, Lexington 40536-0284, USA
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Stanzione P, Traversa R, Pierantozzi M, Semprini R, Marciani MG, Bernardi G. An electrophysiological study of D2 dopaminergic actions in normal human retina: a tool in Parkinson's disease. Neurosci Lett 1992; 140:125-8. [PMID: 1407691 DOI: 10.1016/0304-3940(92)90697-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A peculiar deficit of electrophysiological retinal responses to pattern reversal grating stimuli has been reported in Parkinson's disease (PD) patients. A similar abnormality has been reproduced by means of non-selective dopaminergic antagonists in normal humans. Aim of this study was to verify, by means of a selective D2 antagonist (sulpiride) administered to normal subjects, whether a D2 blockade affects the visual electrophysiological performances with the same trend as observed in PD patients. Patterns electroretinogram (PERG) responses to 1 cycle per degree (c/d) of spatial frequency at 1 (transient) and 7.5 (steady state) Hz of temporal modulation of a square-wave grating pattern reversal have been recorded in 19 healthy volunteers before and after the administration of 100 mg i.m. of sulpiride. The data are consistent for the following conclusion: a selective D2 antagonist reduces steady state and delays transient retinal responses as expected for a PD mimicking agent.
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Affiliation(s)
- P Stanzione
- Clinica Neurologica II Università di Roma Tor Vergata, Italy
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Peppe A, Stanzione P, Pierelli F, Stefano E, Rizzo PA, Tagliati M, Morocutti C. Low contrast stimuli enhance PERG sensitivity to the visual dysfunction in Parkinson's disease. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1992; 82:453-7. [PMID: 1375553 DOI: 10.1016/0013-4694(92)90051-i] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The pattern electroretinogram (PERG) was recorded at different contrast levels (96%, 71%, 47%) in 10 Parkinson's disease patients before and during dopaminergic monotherapy. The data were compared to a control group of 8 normal subjects recorded with the same procedure. PERG P50 latency progressively increased as contrast was decreased both in normal subjects and patients; however, this trend was much more pronounced in PD patients without therapy; consequently in this group the difference between P50 latency obtained with 96% and 47% contrast was statistically significant (P = 0.01, analysis of variance corrected by post-hoc Tukey test). By contrast this was not seen in the control group. Statistical analysis (Bonferroni's t test) showed at the 47% contrast level a significant P50 latency increase (P less than 0.01) in PD patients without therapy if compared with the control group. Dopaminergic monotherapy induced a P50 latency recovery in PD patients. We conclude that low contrast stimuli enhance PERG sensitivity to the visual dysfunction of PD patients. Moreover, the effects observed after therapy confirm that abnormal contrast response functions in PD patients are linked to dopaminergic deficiency.
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Affiliation(s)
- A Peppe
- Istituto di Clinica delle Malattie Nervose e Mentali, Università La Sapienza, Rome, Italy
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Abstract
A new noncorneal electrode for clinical electroretinography was developed. It consists of a thin wire forming a loop modeled to fit into the lower conjunctival sac. Electrical contact is made with the scleral conjunctiva through an exposed portion of otherwise insulated wire. The recorded pattern electroretinograms are in the same amplitude range as if recorded by the gold foil electrode, while the flash electroretinograms with the new electrode are of about two-thirds the amplitude of corneal electrodes. The new electrode is more durable and hence less expensive than gold foil electrodes and can likewise be used without topical anesthetic. Cleaning is easy and effective. The electrode rarely causes discomfort and produces stable responses for at least 2 hours. The electrode aims to match stability of skin electrodes with sensitivity of fragile foil and fiber electrodes.
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Affiliation(s)
- M Hawlina
- University Eye Clinic, Medical Centre Ljubljana, Slovenia
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23
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Falsini B, Bardocci A, Cermola S, Porciatti V, Porrello G. Pattern electroretinogram as a function of spatial frequency after retrobulbar optic neuritis. Doc Ophthalmol 1992; 79:325-36. [PMID: 1633744 DOI: 10.1007/bf00160947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Steady-state (8-Hz) pattern electroretinograms in response to counterphased sinusoidal gratings of variable spatial frequency (0.6-4.8 c/deg) were recorded in 17 patients who had had retrobulbar optic neuritis in one or both eyes (23 eyes with a clinical history of optic neuritis) and in 21 age-matched normal subjects. Amplitude and phase of the Fourier-analyzed pattern electroretinogram second harmonic were measured. The mean pattern electroretinogram amplitude of patients was significantly reduced compared with that of controls. Amplitude reductions were more marked at intermediate (1-1.4 c/deg) than at lower or higher spatial frequencies. Therefore, the average amplitude versus spatial frequency response function differed significantly in patients compared with controls, displaying a lowpass instead of a band-pass shape. No significant differences in the mean pattern electroretinogram phase were observed between groups at any spatial frequency. These results indicate spatial frequency-dependent abnormalities in the pattern electroretinogram amplitude after optic neuritis, suggesting a specific loss of retinal neurons sensitive to stimuli of intermediate spatial frequencies.
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Affiliation(s)
- B Falsini
- Eye Clinic, Catholic University, Rome, Italy
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24
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Tomoda H, Celesia GG, Toleikis SC. Effect of spatial frequency on simultaneous recorded steady-state pattern electroretinograms and visual evoked potentials. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1991; 80:81-8. [PMID: 1707808 DOI: 10.1016/0168-5597(91)90144-m] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pattern electroretinograms (P-ERGs) and visual evoked potentials (VEPs) to 4 Hz alternating square-wave gratings were simultaneously recorded in 23 subjects. Responses were Fourier analyzed and amplitude and phase of the 2nd and 4th temporal harmonics were measured. The spatial frequency-amplitude function of the P-ERG 2nd harmonic component displayed either a bandpass tuning behavior, or a low-pass behavior. The peak amplitude for subjects with bandpass tuning was at 1.5 c/deg. The phase of the P-ERG 2nd harmonic decreased monotonically as spatial frequency increased. The VEP 2nd harmonic had a bimodal spatial frequency function with a peak at 3 c/deg and a second increase at spatial frequencies below 1 c/deg, regardless of the P-ERG characteristics. The phase of VEP 2nd and 4th harmonic had an inverted U-shaped function with peak at 3 c/deg and 1.5 c/deg respectively. Comparison of simultaneously recorded P-ERG and VEP spatial frequency functions demonstrated different tuning behavior for cortical and retinal responses. It is concluded that the proposed technique permits the separate analysis of retinal and cortical processing of visual information. The 2nd and 4th harmonic components of bEP behave independently of each other suggesting they may be generated by different subsystems.
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Affiliation(s)
- H Tomoda
- Department of Neurology, Loyola University Chicago, Stritch School of Medicine, Maywood, IL 60153
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Tomoda H, Celesia GG, Brigell MG, Toleikis S. The effects of age on steady-state pattern electroretinograms and visual evoked potentials. Doc Ophthalmol 1991; 77:201-11. [PMID: 1760969 DOI: 10.1007/bf00161368] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Steady-state pattern-reversal electroretinograms and visual evoked potentials were simultaneously recorded in two groups of young and elderly normal volunteers. The young group consisted of 23 subjects (13 women and 10 men) aged 18 to 28 years, and the elderly group consisted of 24 subjects (11 women and 13 men) aged 58 to 77 years. Stimuli were square-wave gratings ranging in spatial frequency from 0.5 to 6 c/deg and phase reversed at a frequency of 4 Hz. Pattern-reversal electroretinograms and visual evoked potentials consisted of a prominent second and a smaller fourth harmonic response. Spatial frequency-amplitude functions of the pattern-reversal electroretinogram second and fourth harmonics were similar for the young and elderly groups. The mean fourth harmonic phase was significantly shifted in elderly subjects compared with young subjects for all spatial frequencies tested. Spatial frequency tuning was observed for amplitude and phase functions of the visual evoked potential second and fourth harmonic responses for both age groups. Age had a significant effect on phase for spatial frequencies above 1.5 c/deg. Amplitude of the fourth harmonic was significantly lower for the elderly group at 1.5-4 c/deg. Phase was significantly different between groups for spatial frequencies below 3 c/deg. Our results suggest that aging influences both retinal and central visual pathways. Aging differentially affected the visual evoked potential second and fourth harmonic responses, suggesting different neuronal origins for these components.
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Affiliation(s)
- H Tomoda
- Department of Neurology, Loyola University of Chicago, Stritch School of Medicine, Maywood, IL 60153
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Bartel P, Becker P, Robinson E. The intrasession repeatability of pattern electroretinograms and the effects of digital filtering. Doc Ophthalmol 1991; 76:351-8. [PMID: 1935543 DOI: 10.1007/bf00142673] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Transient pattern electroretinograms were recorded in 12 normal young volunteers with the use of 12' and 30' checkerboard stimuli and 1 c/deg and 2.5 c/deg vertical gratings. The intrasession repeatability of pattern electroretinograms was determined by employing alternative statistics to the frequently used correlation coefficients. Comparisons were made with the repeatability of cone electroretinograms elicited by ganzfeld stimulation. The coefficient of repeatability was substantially lower (better) for pattern electroretinogram b-wave implicit times than for a-wave implicit times and b-wave amplitudes, the latter having high coefficients of repeatability. Cone electroretinograms had better repeatability with respect to all three parameters. Digital filtering using a bandpass of 1-40 Hz was applied to the original pattern electroretinograms recorded with a bandpass of 1-250 Hz. Although peak definition was generally enhanced, repeatability did not show marked improvement. Differences between broadband analogue-filtered pattern electroretinograms and the same responses with high-frequency noise removed by digital filtering need to be taken into account. The coefficient of repeatability statistic appears to facilitate the assessment of pattern electroretinograms and permits the comparison of the repeatability of both implicit time and amplitude parameters irrespective of absolute values. The implications of the relatively poor repeatability of pattern electroretinogram b-wave amplitudes for clinical applications need to be considered.
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Affiliation(s)
- P Bartel
- Department of Neurology, University of Pretoria, South Africa
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Affiliation(s)
- J Mishra
- Department of Ophthalmology, University of Texas Medical School, Houston
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