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Lou L, Frishman LJ, Beach KM, Rajagopalan L, Hung LF, She Z, Smith EL, Ostrin LA. Long-term blue light rearing does not affect in vivo retinal function in young rhesus monkeys. Doc Ophthalmol 2023:10.1007/s10633-023-09931-0. [PMID: 36995437 DOI: 10.1007/s10633-023-09931-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 03/09/2023] [Indexed: 03/31/2023]
Abstract
PURPOSE Exposure to blue light is thought to be harmful to the retina. The purpose of this study was to determine the effects of long-term exposure to narrowband blue light on retinal function in rhesus monkeys. METHODS Young rhesus monkeys were reared under short-wavelength "blue" light (n = 7; 465 nm, 183 ± 28 lx) on a 12-h light/dark cycle starting at 26 ± 2 days of age. Age-matched control monkeys were reared under broadband "white" light (n = 8; 504 ± 168 lx). Light- and dark-adapted full-field flash electroretinograms (ERGs) were recorded at 330 ± 9 days of age. Photopic stimuli were brief red flashes (0.044-5.68 cd.s/m2) on a rod-saturating blue background and the International Society for Clinical Electrophysiology of Vision (ISCEV) standard 3.0 white flash on a 30 cd/m2 white background. Monkeys were dark adapted for 20 min and scotopic stimuli were ISCEV standard white flashes of 0.01, 3.0, and 10 cd.s/m2. A-wave, b-wave, and photopic negative response (PhNR) amplitudes were measured. Light-adapted ERGs in young monkeys were compared to ERGs in adult monkeys reared in white light (n = 10; 4.91 ± 0.88 years of age). RESULTS For red flashes on a blue background, there were no significant differences in a-wave (P = 0.46), b-wave (P = 0.75), and PhNR amplitudes (P = 0.94) between white light and blue light reared monkeys for all stimulus energies. ISCEV standard light- and dark-adapted a- and b-wave amplitudes were not significantly different between groups (P > 0.05 for all). There were no significant differences in a- and b-wave implicit times between groups for all ISCEV standard stimuli (P > 0.05 for all). PhNR amplitudes of young monkeys were significantly smaller compared to adult monkeys for all stimulus energies (P < 0.05 for all). There were no significant differences in a-wave (P = 0.19) and b-wave (P = 0.17) amplitudes between young and adult white light reared monkeys. CONCLUSIONS Long-term exposure to narrowband blue light did not affect photopic or scotopic ERG responses in young monkeys. Findings suggest that exposure to 12 h of daily blue light for approximately 10 months does not result in altered retinal function.
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Affiliation(s)
- Linjiang Lou
- College of Optometry, University of Houston, Houston, TX, USA
| | | | - Krista M Beach
- College of Optometry, University of Houston, Houston, TX, USA
| | | | - Li-Fang Hung
- College of Optometry, University of Houston, Houston, TX, USA
- Brien Holden Vision Institute, Sydney, NSW, Australia
| | - Zhihui She
- College of Optometry, University of Houston, Houston, TX, USA
| | - Earl L Smith
- College of Optometry, University of Houston, Houston, TX, USA
- Brien Holden Vision Institute, Sydney, NSW, Australia
| | - Lisa A Ostrin
- College of Optometry, University of Houston, Houston, TX, USA.
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Marmoy OR, Viswanathan S. Clinical electrophysiology of the optic nerve and retinal ganglion cells. Eye (Lond) 2021; 35:2386-2405. [PMID: 34117382 PMCID: PMC8377055 DOI: 10.1038/s41433-021-01614-x] [Citation(s) in RCA: 6] [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: 03/17/2021] [Revised: 05/11/2021] [Accepted: 05/19/2021] [Indexed: 12/28/2022] Open
Abstract
Clinical electrophysiological assessment of optic nerve and retinal ganglion cell function can be performed using the Pattern Electroretinogram (PERG), Visual Evoked Potential (VEP) and the Photopic Negative Response (PhNR) amongst other more specialised techniques. In this review, we describe these electrophysiological techniques and their application in diseases affecting the optic nerve and retinal ganglion cells with the exception of glaucoma. The disease groups discussed include hereditary, compressive, toxic/nutritional, traumatic, vascular, inflammatory and intracranial causes for optic nerve or retinal ganglion cell dysfunction. The benefits of objective, electrophysiological measurement of the retinal ganglion cells and optic nerve are discussed, as are their applications in clinical diagnosis of disease, determining prognosis, monitoring progression and response to novel therapies.
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Affiliation(s)
- Oliver R Marmoy
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK.
- UCL-GOS Institute for Child Health, University College London, London, UK.
- Manchester Metropolitan University, Manchester, UK.
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3
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Tang J, Hui F, Hadoux X, Soares B, Jamieson M, van Wijngaarden P, Coote M, Crowston JG. Short-Term Changes in the Photopic Negative Response Following Intraocular Pressure Lowering in Glaucoma. Invest Ophthalmol Vis Sci 2021; 61:16. [PMID: 32766747 PMCID: PMC7441296 DOI: 10.1167/iovs.61.10.16] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Purpose To evaluate the short-term changes in inner retinal function using the photopic negative response (PhNR) after intraocular pressure (IOP) reduction in glaucoma. Methods Forty-seven participants with glaucoma who were commencing a new or additional IOP-lowering therapy (treatment group) and 39 participants with stable glaucoma (control group) were recruited. IOP, visual field, retinal nerve fiber layer thickness, and electroretinograms (ERGs) were recorded at baseline and at a follow-up visit (3 ± 2 months). An optimized protocol developed for a portable ERG device was used to record the PhNR. The PhNR saturated amplitude (Vmax), Vmax ratio, semi-saturation constant (K), and slope of the Naka–Rushton function were analyzed. Results A significant percentage reduction in IOP was observed in the treatment group (28 ± 3%) compared to the control group (2 ± 3%; P < 0.0001). For PhNR Vmax, there was no significant interaction (F1,83 = 2.099, P = 0.15), but there was a significant difference between the two time points (F1,83 = 5.689, P = 0.019). Post hoc analysis showed a significant difference between baseline and 3 months in the treatment group (mean difference, 1.23 µV; 95% confidence interval [CI], 0.24–2.22) but not in the control group (0.30 µV; 95% CI, 0.78–1.38). K and slope were not significantly different in either group. Improvement beyond test–retest variability was seen in 17% of participants in the treatment group compared to 3% in the control group (P = 0.007, χ2 test). Conclusions The optimized protocol for measuring the PhNR detected short-term improvements in a proportion of participants following IOP reduction, although the majority showed no change.
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Affiliation(s)
- Jessica Tang
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Flora Hui
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Xavier Hadoux
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | | | | | - Peter van Wijngaarden
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Michael Coote
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Jonathan G Crowston
- Glaucoma Research Unit, Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.,Centre for Vision Research, Duke-NUS Medical School, Singapore, Singapore.,Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore
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4
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Prencipe M, Perossini T, Brancoli G, Perossini M. The photopic negative response (PhNR): measurement approaches and utility in glaucoma. Int Ophthalmol 2020; 40:3565-3576. [PMID: 32737731 PMCID: PMC7669808 DOI: 10.1007/s10792-020-01515-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 07/17/2020] [Indexed: 11/22/2022]
Abstract
Purpose Visual electrophysiological testing continues to generate interest among glaucoma experts because of its potential help in clarifying disease pathophysiology and promoting early detection of glaucomatous damage. The photopic negative response (PhNR) is a slow negative component of the full-field electroretinogram that has been shown to provide specific information about retinal ganglion cells (RGCs) activity. The purpose of this article is to review the literature to explore the currently available measurement methods and the utility of PhNR in glaucoma diagnostic process. Methods We gathered publications related to the origins, types of stimuli used, measurements methods and applications of the PhNR of ERG in animal models and humans through a search of the literature cited in PubMed. Search terms were: “PhNR”, “photopic negative response”, “glaucoma”, “glaucomatous optic neuropathy”, “ERG”, “electroretinogram”. Results The most reliable PhNR measurements are obtained using a red stimulus on a blue background, without requiring refractive correction, fixation monitoring, or ocular media transparency. Given its direct correlation with RGCs response, the PhNR measured as baseline-to-trough (BT) represents the most reliable parameter of evaluation. Glaucoma patients with evident perimetric defects show pathologic PhNR values. Even though the PhNR is promising in detecting early RGCs impairment, distinguishing between healthy subjects and suspect patients at risk of developing glaucomatous damage still remains challenging. Conclusion The PhNR is a useful additional tool to explore disorders that affect the innermost retina, including glaucoma and other forms of optic neuropathy. In particular, comparing reports of the standard examinations (optic disc assessment, OCT RNFL measurement, standard automated perimetry) with the results of electrophysiological tests may be helpful in solving clinical diagnostic and management dilemmas. On the one hand, the PhNR of the ERG can examine the parvocellular pathways; on the other hand, the steady-state pattern ERG optimized for glaucoma screening (PERGLA) can explore the magnocellular pathways. This could give ophthalmologists a useful feedback to identify early RGCs alterations suggestive of glaucoma, stratify the risk and potentially monitor disease progression.
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Affiliation(s)
- Matteo Prencipe
- Department of Surgical, Medical, Molecular Pathology and of Critical Area, University of Pisa, Pisa, Italy.
| | - Tommaso Perossini
- Studio Oculistico Associato Mario and Tommaso Perossini, Livorno, Italy
| | | | - Mario Perossini
- Studio Oculistico Associato Mario and Tommaso Perossini, Livorno, Italy
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Hui F, Tang J, Williams PA, McGuinness MB, Hadoux X, Casson RJ, Coote M, Trounce IA, Martin KR, Wijngaarden P, Crowston JG. Improvement in inner retinal function in glaucoma with nicotinamide (vitamin
B3
) supplementation: A crossover randomized clinical trial. Clin Exp Ophthalmol 2020; 48:903-914. [DOI: 10.1111/ceo.13818] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/08/2020] [Accepted: 06/28/2020] [Indexed: 12/26/2022]
Affiliation(s)
- Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Jessica Tang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Pete A. Williams
- Department of Clinical Neuroscience, Division of Eye and Vision St. Erik Eye Hospital, Karolinska Institutet Stockholm Sweden
| | - Myra B. McGuinness
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
| | - Robert J. Casson
- Ophthalmic Research Laboratories, Discipline of Ophthalmology and Visual Sciences University of Adelaide Adelaide Australia
| | - Michael Coote
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Ian A. Trounce
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Keith R. Martin
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
- Department of Clinical Neurosciences University of Cambridge Cambridge UK
| | - Peter Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
| | - Jonathan G. Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital Melbourne Australia
- Ophthalmology, Department of Surgery University of Melbourne Melbourne Australia
- Centre for Vision Research Duke‐NUS Medical School Singapore Singapore
- Singapore Eye Research Institute, Singapore National Eye Centre Singapore Singapore
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Berezovsky A, Karanjia R, Fernandes AG, Botelho GIS, Bueno TLN, Ferraz NN, Sacai PY, Coupland SG, Sadun AA, Salomão SR. Photopic negative response using a handheld mini-ganzfeld stimulator in healthy adults: normative values, intra- and inter-session variability. Doc Ophthalmol 2020; 142:153-163. [PMID: 32681419 DOI: 10.1007/s10633-020-09784-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: 02/21/2020] [Accepted: 07/08/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine normative values, intra- and inter-session variability for a range of parameters derived from the photopic negative response (PhNR) using a handheld mini-Ganzfeld stimulator in healthy normal adults. METHODS Light-adapted flash full-field electroretinograms (ERGs) were recorded from healthy individuals with no visual complaints, visual acuity equal to or better than 0.0 logMAR (20/20 Snellen), and negative family history for visual diseases. ERGs were recorded from both eyes using a DTL® type fiber electrode after dilation of the pupils with instillation of 1 drop of tropicamide eye drops (1%). The full-field PhNR stimulus conditions were produced by a LED-based ColorBurst™ (Diagnosys LLC, Lowell, MA, USA) handheld stimulator. Red flashes of 1, 5 and 7 cd.s/m2 on a blue background of 10 cd/m2 were presented. A-wave, b-wave and PhNR amplitude (determined by both baseline to trough-BT and peak to trough-PT) and peak times were analyzed. Normal limits were determined as 5% percentile for amplitudes and 95% percentile for latencies. Intra- and inter-session variability were assessed with Wilcoxon signed-rank test, intraclass correlation coefficient (ICC) and the coefficient of variability (COV). RESULTS Normative limits for PhNR amplitude (µV) using 1, 5 and 7 cd.s./m2 stimuli were, respectively: 20.81; 18.06 and 19.60 for BT and 69.11; 77.98; 76.51 for PT. Peak times (ms) normative limits for 1, 5 and 7 cd.s/m2 intensities were, respectively, 65.98; 78.20 and 77.96. Overall, intra-session variability assessed by coefficients of variation ranged from 1.35 to 10.28%. Inter-session variability disclosed significant intraclass correlation values for all PhNR parameters only for 1 cd.s/m2 stimuli. CONCLUSIONS The normative values provided by this study are clinically helpful in the diagnosis of inner retinal disorders, especially those affecting retinal ganglion cells such as glaucoma and other optic neuropathies. Further studies, including a larger sample with variable age range would extend the validity of the current results.
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Affiliation(s)
- Adriana Berezovsky
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
| | - Rustum Karanjia
- Doheny Eye Institute, Los Angeles, California, USA.,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Doheny Eye Center, Los Angeles, California, USA.,Ottawa Eye Institute, University of Ottawa, Ottawa, ON, Canada.,Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Arthur Gustavo Fernandes
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Gabriel Izan Santos Botelho
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Tatiane Luana Novele Bueno
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Nívea Nunes Ferraz
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Paula Yuri Sacai
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Stuart Glenn Coupland
- Ottawa Eye Institute, University of Ottawa, Ottawa, ON, Canada.,Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Alfredo Arrigo Sadun
- Doheny Eye Institute, Los Angeles, California, USA.,Department of Ophthalmology, David Geffen School of Medicine at UCLA, Doheny Eye Center, Los Angeles, California, USA
| | - Solange Rios Salomão
- Departamento de Oftalmologia e Ciências Visuais, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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7
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The rapid N-wave as a potentially useful measure of the photopic negative response. Doc Ophthalmol 2020; 141:253-257. [PMID: 32507902 DOI: 10.1007/s10633-020-09769-w] [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: 11/18/2019] [Accepted: 04/30/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE The photopic negative response (PhNR) correlates with ganglion cell function and has previously been examined as an indicator of glaucomatous optic nerve damage. However, it is a prolonged response that is measured against baseline, and its clinical utility has been limited by extensive variability, poor repeatability, and baseline instability. We have observed a distinct brief negative wave ("N-wave") commonly present within the slow PhNR trough, which may provide practical and analytic advantages as a clinical measure. METHODS We reviewed data from an interventional trial of 59 glaucoma patients who had 4 exams over an 8-month period. The PhNR was recorded with standard ISCEV stimuli (1 Hz and in some cases 4 Hz stimulation), and N-waves were measured manually, relative to return to baseline. RESULTS N-waves, when present, could be measured easily despite shifting baselines and a degree of background noise. The PhNR median amplitude centered around 18 μV, while the N-wave median centered around 7 μV, with a distribution of responses skewed toward low or zero amplitudes. CONCLUSIONS The N-wave appears to be a component of the longer PhNR, though its exact origin and significance remain unclear. As a rapid waveform that is independent of baseline, the N-wave is in many ways easier to measure accurately than the slower PhNR, which is highly dependent on baseline stability. The N-wave may prove useful clinically if further studies can optimize its stimulation, show its behavior in normal individuals and find correlation with markers of optic nerve disease.
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8
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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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9
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The photopic negative response of the Light-adapted 3.0 ERG in clinical settings. Doc Ophthalmol 2019; 140:115-128. [DOI: 10.1007/s10633-019-09723-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 09/16/2019] [Indexed: 11/27/2022]
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10
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Hui F, Tang J, Hadoux X, Coote M, Crowston JG. Optimizing a Portable ERG Device for Glaucoma Clinic: The Effect of Interstimulus Frequency on the Photopic Negative Response. Transl Vis Sci Technol 2018; 7:26. [PMID: 30619646 PMCID: PMC6314062 DOI: 10.1167/tvst.7.6.26] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 10/12/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to investigate the effect of interstimulus frequency on the photopic negative response (PhNR) in the clinical electroretinogram (ERG) in glaucoma and healthy eyes. Methods Participants with open angle glaucoma (n = 15) and age-matched controls (n = 20) were recruited. Photopic ERGs were recorded in one eye using five frequencies (1-5 Hz) delivered in random order. ERGs were analyzed for changes to amplitude and timing between groups and interstimulus frequency. Coefficient of variation (CoV) was used to examine variability within recordings for each frequency. Results While the a-wave and b-wave showed minimal alteration, the PhNR was highly sensitive to changes in interstimulus frequency. The PhNR signal was largest at 1 Hz and steadily diminished with higher frequencies in both control and glaucoma groups. Significant differences in PhNR amplitude were found between controls and glaucoma groups at 2 and 3 Hz. While 1 Hz delivered the largest PhNR, it also showed a significantly greater CoV compared to other frequencies. Conclusions An interstimulus frequency of 2 Hz was optimal for recording the PhNR, creating a good balance between testing time and signal quality. A higher frequency could be used to further shorten clinical testing times; however, this may compromise its clinical utility by dampening the PhNR. Translational Relevance Here we show the importance of considering flash interstimulus frequency when designing ERG protocols for recording the PhNR as while higher frequencies can shorten test times, they also have considerable effects on the PhNR.
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Affiliation(s)
- Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Jessica Tang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Michael Coote
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
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11
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Tang J, Hui F, Hadoux X, Sarossy M, van Wijngaarden P, Coote M, Crowston JG. A Comparison of the RETeval Sensor Strip and DTL Electrode for Recording the Photopic Negative Response. Transl Vis Sci Technol 2018; 7:27. [PMID: 30619647 PMCID: PMC6314057 DOI: 10.1167/tvst.7.6.27] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Accepted: 10/12/2018] [Indexed: 12/02/2022] Open
Abstract
PURPOSE To compare the RETeval sensor strip and Dawson-Trick-Litzkow (DTL) electrodes for recording the photopic negative response (PhNR) using a portable electroretinogram (ERG) device in eyes with and without glaucoma. METHODS Twenty-six control and 31 glaucoma or glaucoma-suspect participants were recruited. Photopic ERGs were recorded with sensor strip and DTL electrodes in random order using the LKC RETeval device. Stimuli consisted of brief, red flashes (1.7 cd.s/m2) on a blue background (photopic 10 cd/m2). The PhNR amplitude was measured from baseline to trough and also expressed as a ratio over the b-wave amplitude. RESULTS The sensor strip-recorded PhNR amplitude was significantly attenuated (mean ± standard deviation [SD], 4.8 ± 2.1 vs. 12.7 ± 4.8 μV, P < 0.0001), with lower signal-to-noise ratio (SNR; 5.5 ± 2.1 vs. 8.1 ± 3.9, P < 0.0001), and a trend toward a larger PhNR/b-wave ratio compared with DTL electrodes. The PhNR amplitude, implicit time and PhNR/b-wave ratio correlated with visual field mean light sensitivity, although this fell short of significance for the sensor strip recorded PhNR amplitude. The electrodes demonstrated similar intersession repeatability with a coefficient of repeatability of ±27% and ±28% for the DTL and sensor strip, respectively. CONCLUSIONS Sensor strip electrodes are a viable alternative for recording reproducible PhNRs, especially when values are normalized to the b-wave. However, DTL electrodes should be considered in cases of attenuated PhNR, or in elevated noise levels, due to its better signal-to-noise quality. TRANSLATIONAL RELEVANCE Sensor strip electrodes can simplify PhNR recordings in the clinic, potentially eliminating the need for an experienced operator.
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Affiliation(s)
- Jessica Tang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
| | - Marc Sarossy
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Peter van Wijngaarden
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Michael Coote
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia
- Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
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Tang J, Hui F, Coote M, Crowston JG, Hadoux X. Baseline Detrending for the Photopic Negative Response. Transl Vis Sci Technol 2018; 7:9. [PMID: 30258702 PMCID: PMC6152608 DOI: 10.1167/tvst.7.5.9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/05/2018] [Indexed: 11/24/2022] Open
Abstract
Purpose The photopic negative response (PhNR) of the light-adapted electroretinogram (ERG) holds promise as an objective marker of retinal ganglion cell function. We compared baseline detrending methods to improve PhNR repeatability without compromising its diagnostic ability in glaucoma. Methods Photopic ERGs were recorded in 20 glaucoma and 18 age-matched control participants. A total of 50 brief, red-flashes (1.6 cd.s/m2) on a blue background (10 photopic cd/m2) were delivered using the RETeval device. Detrending methods compared were: (1) increasing the high-pass filter from 1 to 10 Hz and (2) estimating and removing the trend with an increasing polynomial (order from 1–10) applied to the prestimulus interval, prestimulus and postsignal interval, or the whole ERG signal. Coefficient of repeatability (COR%), unpaired Student's t-test, and area under the receiver operating characteristic curve (AUC) were used to compare the detrending methods. Results Most detrending methods improved PhNR test–retest repeatability compared to the International Society for Clinical Electrophysiology of Vision (ISCEV) recommended 0.3 to 300 Hz band-pass filter (COR% ± 200%). In particular, detrending with a polynomial (order 3) applied to the whole signal performed the best (COR% ± 44%) while achieving similar diagnostic ability as ISCEV band-pass (AUC 0.74 vs. 0.75, respectively). However, over-correcting with higher orders of processing can cause waveform distortion and reduce diagnostic ability. Conclusions Baseline detrending can improve the PhNR repeatability without compromising its clinical use in glaucoma. Further studies exploring more complex processing methods are encouraged. Translational Relevance Baseline detrending can significantly improve the quality of the PhNR.
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Affiliation(s)
- Jessica Tang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Michael Coote
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Jonathan G Crowston
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Xavier Hadoux
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
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13
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Frishman L, Sustar M, Kremers J, McAnany JJ, Sarossy M, Tzekov R, Viswanathan S. ISCEV extended protocol for the photopic negative response (PhNR) of the full-field electroretinogram. Doc Ophthalmol 2018; 136:207-211. [PMID: 29855761 PMCID: PMC6061118 DOI: 10.1007/s10633-018-9638-x] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/09/2018] [Indexed: 11/24/2022]
Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) Standard for full-field electroretinography (ERG) describes a minimum procedure, but encourages more extensive testing. This ISCEV extended protocol describes an extension to the ERG Standard, namely the photopic negative response (PhNR) of the light-adapted flash ERG, as a well-established technique that is broadly accepted by experts in the field. The PhNR is a slow negative-going wave after the b-wave that provides information about the function of retinal ganglion cells and their axons. The PhNR can be reduced in disorders that affect the innermost retina, including glaucoma and other forms of optic neuropathy. This document, based on existing literature, provides a protocol for recording and analyzing the PhNR in response to a brief flash. The protocol includes full-field stimulation, a frequency bandwidth of the recording in which the lower limit does not exceed 0.3 Hz, and a spectrally narrowband stimulus, specifically, a red flash on a rod saturating blue background. Suggested flash strengths cover a range up to and including the minimum required to elicit a maximum amplitude PhNR. This extended protocol for recording the PhNR provides a simple test of generalized retinal ganglion cell function that could be added to standard ERG testing.
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Affiliation(s)
- Laura Frishman
- College of Optometry, University of Houston, Houston, TX, USA.
| | - Maja Sustar
- Eye Hospital, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Jan Kremers
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - J Jason McAnany
- Department of Ophthalmology and Visual Sciences, Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Marc Sarossy
- Department of Ophthalmology, Centre for Eye Research Australia, The Royal Victorian Eye and Ear Hospital, University of Melbourne, Melbourne, VIC, Australia
| | - Radouil Tzekov
- Department of Ophthalmology, University of South Florida, Tampa, FL, USA
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14
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Joshi NR, Ly E, Viswanathan S. Intensity response function of the photopic negative response (PhNR): effect of age and test-retest reliability. Doc Ophthalmol 2017; 135:1-16. [PMID: 28508299 DOI: 10.1007/s10633-017-9591-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/03/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To assess the effect of age and test-retest reliability of the intensity response function of the full-field photopic negative response (PhNR) in normal healthy human subjects. METHODS Full-field electroretinograms (ERGs) were recorded from one eye of 45 subjects, and 39 of these subjects were tested on two separate days with a Diagnosys Espion System (Lowell, MA, USA). The visual stimuli consisted of brief (<5 ms) red flashes ranging from 0.00625 to 6.4 phot cd.s/m2, delivered on a constant 7 cd/m2 blue background. PhNR amplitudes were measured at its trough from baseline (BT) and from the preceding b-wave peak (PT), and b-wave amplitude was measured at its peak from the preceding a-wave trough or baseline if the a-wave was not present. The intensity response data of all three ERG measures were fitted with a generalized Naka-Rushton function to derive the saturated amplitude (V max), semisaturation constant (K) and slope (n) parameters. Effect of age on the fit parameters was assessed with linear regression, and test-retest reliability was assessed with the Wilcoxon signed-rank test and Bland-Altman analysis. Holm's correction was applied to account for multiple comparisons. RESULTS V max of BT was significantly smaller than that of PT and b-wave, and the V max of PT and b-wave was not significantly different from each other. The slope parameter n was smallest for BT and the largest for b-wave and the difference between the slopes of all three measures were statistically significant. Small differences observed in the mean values of K for the different measures did not reach statistical significance. The Wilcoxon signed-rank test indicated no significant differences between the two test visits for any of the Naka-Rushton parameters for the three ERG measures, and the Bland-Altman plots indicated that the mean difference between test and retest measurements of the different fit parameters was close to zero and within 6% of the average of the test and retest values of the respective parameters for all three ERG measurements, indicating minimal bias. While the coefficient of reliability (COR, defined as 1.96 times the standard deviation of the test and retest difference) of each fit parameter was more or less comparable across the three ERG measurements, the %COR (COR normalized to the mean test and retest measures) was generally larger for BT compared to both PT and b-wave for each fit parameter. The Naka-Rushton fit parameters did not show statistically significant changes with age for any of the ERG measures when corrections were applied for multiple comparisons. However, the V max of BT demonstrated a weak correlation with age prior to correction for multiple comparisons, and the effect of age on this parameter showed greater significance when the measure was expressed as a ratio of the V max of b-wave from the same subject. CONCLUSION V max of the BT amplitude measure of PhNR at the best was weakly correlated with age. None of the other parameters of the Naka-Rushton fit to the intensity response data of either the PhNR or the b-wave showed any systematic changes with age. The test-retest reliability of the fit parameters for PhNR BT amplitude measurements appears to be lower than those of the PhNR PT and b-wave amplitude measurements.
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Affiliation(s)
- Nabin R Joshi
- College of Optometry, State University of New York, 33 West 42nd Street, New York, NY, 10036, USA
| | - Emma Ly
- Southern California College of Optometry, Marshall B. Ketchum University, Fullerton, CA, USA
| | - Suresh Viswanathan
- College of Optometry, State University of New York, 33 West 42nd Street, New York, NY, 10036, USA.
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Abstract
PURPOSE OF REVIEW Electrophysiological measures of vision function have for decades generated interest among glaucoma researchers and clinicians alike because of their potential to help elucidate pathophysiological processes and sequence of glaucomatous damage, as well as to offer a potential complementary metric of function that might be more sensitive than standard automated perimetry. The purpose of this article is to review the recent literature to provide an update on the role of the electroretinogram (ERG) in glaucoma diagnosis. RECENT FINDINGS The pattern reversal ERG (PERG) and the photopic negative response (PhNR) of the cone-driven full-field, focal or multifocal ERG provide objective measures of retinal ganglion cell function and are all sensitive to glaucomatous damage. Recent studies demonstrate that a reduced PERG amplitude is predictive of subsequent visual field conversion (from normal to glaucomatous) and an increased rate of progressive retinal nerve fiber layer thinning in suspect eyes, indicating a potential role for PERG in risk stratification. Converging evidence indicates that some portion of PERG and PhNR abnormality represents a reversible aspect of dysfunction in glaucoma. SUMMARY PERG and PhNR responses obtained from the central macula are capable of detecting early-stage, reversible glaucomatous dysfunction.
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Wang J, Cheng H, Hu YS, Tang RA, Frishman LJ. The photopic negative response of the flash electroretinogram in multiple sclerosis. Invest Ophthalmol Vis Sci 2012; 53:1315-23. [PMID: 22273726 DOI: 10.1167/iovs.11-8461] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To use the photopic electroretinogram (ERG) to evaluate retinal function in eyes of multiple sclerosis (MS) patients with and without a history of optic neuritis (ON) and to compare the functional and structural status of the inner retina. METHODS Full-field ERG responses to brief red flashes (0.04-2.8 cd · s/m²) on a rod-saturating blue background were recorded from 51 MS patients and 33 age-matched control subjects. In patients, perimetry was performed and peripapillary retinal nerve fiber layer thickness (RNFLT) was assessed by optical coherence tomography (OCT) and scanning laser polarimetry (SLP). MS eyes were separated into groups: "ON >6" months (n = 25), "ON <6" months (n = 29), and "no ON" (n = 33) based on positive or negative history of ON and time since the last episode. Thirteen ON<6 eyes were re-evaluated 1 year later. RESULTS PhNR amplitudes were lower in ON>6, ON<6, and no-ON eyes (mean ± SD, 17.3 ± 7.6, 16.0 ± 6.5, and 23.8 ± 9.3 μV, respectively), than in control eyes (29.8 ± 6.5 μV; P < 0.001) for a standard stimulus of 1.42 cd · s/m²; a- and b-wave amplitudes were unaffected. PhNR amplitudes correlated with visual fields mean deviation (MD) in ON>6 (r² = 0.43; P < 0.001) and no-ON eyes (r² = 0.10; P < 0.05), with similar results for weaker stimuli. PhNR amplitudes correlated with RNFLT in ON>6 eyes: OCT (r² = 0.52; P < 0.0001) and SLP (r² = 0.51; P < 0.01); and in no-ON eyes, OCT (r² = 0.21; P < 0.01) and SLP (r² = 0.17; P < 0.05). ON<6 amplitudes did not correlate significantly with other measures, but increased after 1 year by 5.1 ± 3.1 μV (P < 0.001), visual fields MD increased by 1.8 ± 2.3 dB (P < 0.05), and RNFL loss persisted. CONCLUSIONS Photopic ERG PhNR amplitudes in MS patients are significantly reduced in eyes with and without a history of ON.
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Affiliation(s)
- Jing Wang
- College of Optometry, University of Houston, Houston, Texas, USA
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Kremers J, Jertila M, Link B, Pangeni G, Horn FK. Spectral characteristics of the PhNR in the full-field flash electroretinogram of normals and glaucoma patients. Doc Ophthalmol 2012; 124:79-90. [DOI: 10.1007/s10633-011-9304-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 12/12/2011] [Indexed: 11/29/2022]
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