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Chan HH, Ng Y, Chu PH. Applications of the multifocal electroretinogram in the detection of glaucoma. Clin Exp Optom 2021; 94:247-58. [DOI: 10.1111/j.1444-0938.2010.00571.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Henry Ho‐lung Chan
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. E‐mail:
| | - Yui‐fai Ng
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. E‐mail:
| | - Patrick Ho‐wai Chu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. E‐mail:
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Applying a New Automated Perimetry Pattern Based on the Stimulus Distribution of the Multifocal ERG to Improve Structure-Function Investigation in Glaucoma. J Ophthalmol 2017; 2017:8780934. [PMID: 29238616 PMCID: PMC5697167 DOI: 10.1155/2017/8780934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 06/07/2017] [Accepted: 09/12/2017] [Indexed: 11/28/2022] Open
Abstract
Purpose To validate a new automated perimetry pattern (mf103 pattern) for the investigation of retinal structure-function relationships in glaucoma in comparison to the standard G2 pattern and to relate either field's performance to optical coherence tomography (OCT). Methods Automated perimetry data from the mfERG103 pattern were compared with the standard G2 pattern in glaucoma patients (18) and controls (15). The results of both (mean defect (MD) and mean sensitivity (MS)) were compared with optical coherence tomography (OCT): retinal nerve fiber layer (RNFL) thickness, macular thickness (mT), and ganglion cell analysis (GCIPL). Nine patients were followed up after one year. Results G2 pattern and mf103 pattern did not differ significantly in MD or MS. The mf103 pattern associated significantly with more RNFL sectors in both MD and MS (p < 0.01 and p < 0.05, resp.). GCIPL thickness was not significantly associated with either SAP protocols. Both protocols remained comparable after one-year follow-up. Conclusions G2 and mf103 pattern can both differentiate patients from controls with no significant difference in performance. RNFL thickness defects correlated better with mf103 than G2 with POAG. The mfERG-103 perimetry pattern can be used to establish structure-function correlations in glaucoma and may enable a more direct comparison with objective electrophysiological data.
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Brandao LM, Ledolter AA, Monhart M, Schötzau A, Palmowski-Wolfe AM. Ganglion cell layer segmentation and the two-flash multifocal electroretinogram improve structure function analysis in early glaucoma. Graefes Arch Clin Exp Ophthalmol 2017; 255:1991-2000. [PMID: 28779363 PMCID: PMC5602085 DOI: 10.1007/s00417-017-3722-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 06/01/2017] [Accepted: 06/13/2017] [Indexed: 12/01/2022] Open
Abstract
Purpose To improve structure-function analysis in primary open-angle glaucoma (POAG) by including the two-global flash multifocal electroretinogram (2F–mfERG) and macular ganglion cell layer segmentation. Methods Twenty-five glaucoma patients (six pre-perimetric (PPG), 19 POAG) and 16 controls underwent 2F–mfERG, optical coherence tomography (OCT), and standard automated perimetry (SAP). For 2F–mfERG, the root mean square was calculated for the focal flash response at 15–45 ms (DC) and the global flash responses at 45–75 ms (IC1) and 75–105 ms (IC2). For OCT, macular total thickness (mT) and ganglion cell-inner plexiform layer (GCIPL) thickness were analysed. Values from the central 10° and 15° of 2F-mfERG were compared to the corresponding areas from OCT and visual field. Results Both PPG and POAG had significantly lower mfERG responses in the central 10° and 15° than the control group. Of the glaucoma patients, 30.7% (three PPG, five POAG) showed central mfERG and GCIPL reduction without a SAP defect in the central 15 degrees. Four patients had a central SAP defect associated with a reduced GCIPL without any detectable dysfunction on mfERG. MfERG DC and IC2 were larger with increased mT (p ≤ 0.02), but GCIPL only related positively to IC2 (p = 0.027). SAP sensitivity also increased with thicker mT but not with GCIPL (p < 0.03 and p = 0.35). DC, IC2, and GCIPL could best differentiate glaucoma from control (AUC values: 0.897, 0.903, and 0.905). Conclusions Structure function analysis in glaucoma can be improved when the GCIPL thickness as well as the 2F–mfERG is included as these measures complement information obtained by SAP.
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Affiliation(s)
- Livia M Brandao
- Department of Ophthalmology, University of Basel, Basel, Switzerland. .,Universitätsspital Basel Augenklinik, Mittlere Strasse 91, 4031, Basel, Switzerland.
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | | | - Andreas Schötzau
- Department of Ophthalmology, University of Basel, Basel, Switzerland
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Brandao LM, Monhart M, Schötzau A, Ledolter AA, Palmowski-Wolfe AM. Wavelet decomposition analysis in the two-flash multifocal ERG in early glaucoma: a comparison to ganglion cell analysis and visual field. Doc Ophthalmol 2017; 135:29-42. [PMID: 28593391 PMCID: PMC5532413 DOI: 10.1007/s10633-017-9593-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/23/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To further improve analysis of the two-flash multifocal electroretinogram (2F-mfERG) in glaucoma in regard to structure-function analysis, using discrete wavelet transform (DWT) analysis. METHODS Sixty subjects [35 controls and 25 primary open-angle glaucoma (POAG)] underwent 2F-mfERG. Responses were analyzed with the DWT. The DWT level that could best separate POAG from controls was compared to the root-mean-square (RMS) calculations previously used in the analysis of the 2F-mfERG. In a subgroup analysis, structure-function correlation was assessed between DWT, optical coherence tomography and automated perimetry (mf103 customized pattern) for the central 15°. RESULTS Frequency level 4 of the wavelet variance analysis (144 Hz, WVA-144) was most sensitive (p < 0.003). It correlated positively with RMS but had a better AUC. Positive relations were found between visual field, WVA-144 and GCIPL thickness. The highest predictive factor for glaucoma diagnostic was seen in the GCIPL, but this improved further by adding the mean sensitivity and WVA-144. CONCLUSIONS mfERG using WVA analysis improves glaucoma diagnosis, especially when combined with GCIPL and MS.
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Affiliation(s)
- Livia M Brandao
- Department of Ophthalmology, Basel University Hospital, Basel, BS, Switzerland.
- Universitätsspital Basel Augenklinik, Mittlere Strasse 91, 4031, Basel, Switzerland.
| | | | - Andreas Schötzau
- Department of Ophthalmology, Basel University Hospital, Basel, BS, Switzerland
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
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Sørensen NB, Christiansen AT, Kjær TW, Klemp K, la Cour M, Kiilgaard JF. Time-Dependent Decline in Multifocal Electroretinogram Requires Faster Recording Procedures in Anesthetized Pigs. Transl Vis Sci Technol 2017; 6:6. [PMID: 28377845 PMCID: PMC5374880 DOI: 10.1167/tvst.6.2.6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 01/11/2017] [Indexed: 11/24/2022] Open
Abstract
Purpose The time-dependent effect of anesthetics on the retinal function is debated. We hypothesize that in anesthetized animals there is a time-dependent decline that requires optimized multifocal electroretinogram (mfERG) recording procedures. Methods Conventional and four-frame global-flash mfERG recordings were obtained approximately 15, 60, and 150 minutes after the induction of propofol anesthesia (20 pigs) and isoflurane anesthesia (nine pigs). In six of the propofol-anesthetized pigs, the mfERG recordings were split in 3-minute segments. Two to 4 weeks after initial recordings, an intraocular injection of tetrodotoxin (TTX) was given and the mfERG was rerecorded as described above. Data were analyzed using mixed models in SAS statistical software. Results Propofol significantly decreases the conventional and global-flash amplitudes over time. The only significant effect of isoflurane is a decrease in the global-flash amplitudes. At 15 minutes after TTX injection several of the mfERG amplitudes are significantly decreased. There is a linear correlation between the conventional P1 and the global-flash DR mfERG-amplitude (R2 = 0.82, slope = 0.72, P < 0.0001). There is no significant difference between the 3-minute and the prolonged mfERG recordings for conventional amplitudes and the global-flash direct response. The global flash–induced component significantly decreases with prolonged mfERG recordings. Conclusions A 3-minute mfERG recording and a single stimulation protocol is sufficient in anesthetized pigs. Recordings should be obtained immediately after the induction of anesthesia. The effect of TTX is significant 15 minutes after injection, but is contaminated by the effect of anesthesia 90 minutes after injection. Therefore, the quality of mfERG recordings can be further improved by determining the necessary time-of-delay from intraocular injection of a drug to full effect. Translational Relevance General anesthesia is a possible source of error in mfERG recordings. Therefore, it is important to investigate the translational relevance of the results to mfERG recordings in children in general anesthesia.
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Affiliation(s)
- Nina Buus Sørensen
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | | | | | - Kristian Klemp
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Morten la Cour
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Jens Folke Kiilgaard
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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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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Ledolter AA, Monhart M, Schoetzau A, Todorova MG, Palmowski-Wolfe AM. Structural and functional changes in glaucoma: comparing the two-flash multifocal electroretinogram to optical coherence tomography and visual fields. Doc Ophthalmol 2015; 130:197-209. [PMID: 25616700 DOI: 10.1007/s10633-015-9482-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 01/15/2015] [Indexed: 01/05/2023]
Abstract
PURPOSE To correlate multifocal electroretinogram (mfERG) findings in the macular area of glaucoma patients with automated perimetry (visual fields) and with optical coherence tomography (OCT). METHODS A two-global flash mfERG (VERIS™) was recorded in 20 eyes with primary open-angle glaucoma. The root mean square was calculated, and three response epochs were analysed: the direct component (15-45 ms) and two induced components (IC-1 at 45-75 ms and IC-2 at 75-105 ms). The central 10° of the mfERG was compared to the central 10° of the OCT and of the visual field. Responses grouped in a superior and in an inferior semicircle, extending between 10° and 20°, were also compared to the corresponding areas of the OCT and of the visual fields. In addition, the area of the papillomacular bundle was also analysed separately. RESULTS In glaucoma patients, mfERG responses showed a significant positive association with retinal thickness in the central 10° for IC2 (p = 0.001) and a trend for IC1 (p = 0.066). A significant association was found between the central IC1 and IC2 of the mfERG and corresponding perimetric sensitivities expressed in linear units (p < 0.01). The OCT showed a positive association with visual field sensitivities (p < 0.05) in all areas examined (p < 0.05). Separation of the papillomacular bundle area did not improve structure-function association further. CONCLUSIONS In our study, mfERG showed a statistically significant correlation with perimetric sensitivity measured in linear units and with structural macular changes detected with time-domain OCT.
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Affiliation(s)
- Anna A Ledolter
- Department of Ophthalmology, University of Basel, Basel, Switzerland,
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Ledolter AA, Todorova MG, Schoetzau A, Palmowski-Wolfe AM. Impact of a Digital Power Line Filter in the 2-Global-Flash Multifocal Electroretinogram of Glaucoma Patients Compared to Controls. Curr Eye Res 2015; 41:70-8. [PMID: 25612055 DOI: 10.3109/02713683.2014.1002043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To assess the effect of a 50 Hz power line digital filter on the response to a 2-global-flash multifocal electroretinogram (mfERG) in primary open angle glaucoma (POAG) compared to control. MATERIALS AND METHODS A 2-global-flash mfERG (VERIS™) was recorded (23 control, 34 POAG). Eight recordings were noise contaminated: 4 control, 4 POAG. Response averages from the central 10° and 7 surrounding groups were analyzed with and without a 50 Hz digital filter for the following mfERG response epochs: direct component (15-45 ms), 1st (45-75 ms) and 2nd (75-105 ms) induced components. RESULTS A digital 50 Hz filter had little effect on uncontaminated with noise waveforms but, in noisy recordings, changed the waveform dramatically to resemble uncontaminated waveforms. In controls' 50 Hz-filtered uncontaminated with noise mfERGs differed significantly from unfiltered responses in induced components. Uncontaminated with noise recordings from glaucoma patients did not differ with or without the notch filter (p > 0.1 for all three epochs of mfERG). The mfERG response in the central 10°in glaucoma patients differed significantly from controls, whether the notch filter was used or not (p < 0.001). CONCLUSIONS A 50 Hz notch filter allows grossly contaminated waveforms to be analyzed in a meaningful manner. With a 50 Hz filter, glaucoma patients still differed significantly from normal.
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Affiliation(s)
- Anna A Ledolter
- a Department of Ophthalmology , University of Basel , Basel , Switzerland and.,b Department of Ophthalmology , University of Vienna , Vienna , Austria
| | | | - Andreas Schoetzau
- a Department of Ophthalmology , University of Basel , Basel , Switzerland and
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Luo X, Patel NB, Rajagopalan LP, Harwerth RS, Frishman LJ. Relation between macular retinal ganglion cell/inner plexiform layer thickness and multifocal electroretinogram measures in experimental glaucoma. Invest Ophthalmol Vis Sci 2014; 55:4512-24. [PMID: 24970256 DOI: 10.1167/iovs.14-13937] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We investigated relations between macular retinal ganglion cell plus inner plexiform layer (RGC+IPL) thickness and macular retinal function revealed by multifocal electroretinonography (mfERG) in a nonhuman primate model of experimental glaucoma. METHODS Retinal ganglion cell (RGC) structure and function were followed with spectral-domain optical coherence tomography (SD-OCT) and ERGs in five macaques with unilateral experimental glaucoma. Linear regression was used to study correlations in control (Con) and experimental (Exp) eyes between peripapillary retinal nerve fiber layer (RNFL) thickness, macular RGC+IPL thickness, multifocal photopic negative response (mfPhNR) and high-frequency multifocal oscillatory potentials (mfOP) in slow-sequence mfERG, and low-frequency component (mfLFC) in global-flash mfERG. We used ANOVA and paired t-tests to compare glaucoma-related mfERG changes between superior and inferior hemifields, foveal hexagon, inner three rings, and four quadrants of macula. RESULTS Average macular RGC+IPL and temporal RNFL thickness were strongly correlated (r(2) = 0.90, P < 0.001). In hexagon-by-hexagon analysis, all three mfERG measures were correlated (P < 0.001) with RGC+IPL thickness for Con (r(2), 0.33-0.51) and Exp eyes (r(2), 0.17-0.35). The RGC structural and functional metrics decreased as eccentricity increased. The reduction in amplitude of mfERG measures in Exp eyes relative to Con eyes was proportionally greater, in general, than the relative thinning of RGC+IPL at the same location for eyes in which structural loss was not evident, or mild to moderate. Although not statistically significant, percent amplitude reduction of mfERG measures was greatest in the inferior temporal quadrant. CONCLUSIONS Macular RGC+IPL thickness and mfERG measures of RGC function can be complementary tools in assessing glaucomatous neuropathy.
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Affiliation(s)
- Xunda Luo
- University of Houston, College of Optometry, Houston, Texas, United States
| | - Nimesh B Patel
- University of Houston, College of Optometry, Houston, Texas, United States
| | | | - Ronald S Harwerth
- University of Houston, College of Optometry, Houston, Texas, United States
| | - Laura J Frishman
- University of Houston, College of Optometry, Houston, Texas, United States
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Effect of lycium barbarum (wolfberry) polysaccharides on preserving retinal function after partial optic nerve transection. PLoS One 2013; 8:e81339. [PMID: 24339917 PMCID: PMC3858224 DOI: 10.1371/journal.pone.0081339] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 10/20/2013] [Indexed: 11/28/2022] Open
Abstract
Lycium Barbarum Polysaccharides (LBP) are the active components of Wolfberry (a traditional Chinese medicine) which has long been used for improving visual function. This study aims to investigate localized changes of retinal function in a partial optic nerve transection (PONT) model, and effects of LBP on visual function. The multifocal electroretinograms (mfERG) were obtained from 30 eyes of 30 Sprague-Dawley rats. The rats were divided into 6 groups (five treatment groups and one control group). Starting from the first day of the experiment, the rats in the (PONT+LBP) group and the (LBP) group were dosed with LBP; rats in the (PONT+PBS (phosphate buffered saline)) group and the (PBS) group were dosed with PBS via nasogastric tube every day until euthanized. The dorsal part of the optic nerve was transected in the (PONT), (PONT+LBP) and (PONT+PBS) groups at the end of week 1 (day 7 after LBP or PBS feeding began). The mfERG was measured at three time points: week 2, week 3 and week 5. Significant reduction of P1 and PhNR amplitudes of the mfERG were observed in all retinal regions a week after PONT. Feeding with LBP prior to PONT preserved retinal function. All mfERG responses returned to the normal range in the superior retina, which corresponds to the transected dorsal region of the optic nerve, while most of the inferior retinal responses were significantly increased at week 4 after PONT. The ventral part of the retina had secondary degeneration which was not only limited to the ganglion cell layer, but is a widespread effect affecting the outer retina. LBP altered the functional reduction caused by PONT by regulating the signal from the outer retina.
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Ledolter AA, Kramer SA, Todorova MG, Schötzau A, Palmowski-Wolfe AM. The effect of filtering on the two-global-flash mfERG: identifying the optimal range of frequency for detecting glaucomatous retinal dysfunction. Doc Ophthalmol 2012; 126:117-23. [PMID: 23224265 DOI: 10.1007/s10633-012-9364-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 11/26/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE To study the effects of filtering bandwidth on the two-global-flash multifocal electroretinogram (mfERG) responses in primary open-angle glaucoma (POAG) compared with control subjects. METHODS A two-global-flash mfERG (VERIS 6.06™, FMS III) was recorded in 20 healthy subjects and 22 POAG patients with a band-pass filter (BPF) of 1-300 Hz (103 Hexagons, M-sequence stimulus: Lmax 100 cd/m(2), Lmin < 1 cd/m(2), global flash: 200 cd/m(2)). The root-mean-square average of the central 10° was calculated. Three response epochs were analysed: the response to the focal flash, at 15-45 ms (DC), and the following two components induced by the effects of the preceding focal flash on the response to the global flashes at 45-75 ms (IC1) and at 75-105 ms (IC2). The following BPF settings were analysed: 1-300 Hz, 3-300 Hz, 10-300 Hz, 100-300 Hz, 200-300 Hz, 1-10 Hz, 1-100 Hz and 1-200 Hz. RESULTS Filtering at 1-300 Hz showed significantly lower responses in POAG than in control subjects (p < 0.001) for all epochs analysed. At 1-100 Hz, this also held true even though the difference between the groups became smaller. At 1-10 Hz, responses were extremely small and did not differ between POAG and control (p > 0.5). This would suggest a filter setting of 10-300 Hz for mfERG recordings in POAG. However, when a filter setting of 10-300 Hz was compared to 1-300 Hz, with a filter setting of 10-300 Hz, the DC in POAG differed more (p < 0.0001) from normal than with 1-300 Hz (p = 0.0002). For IC1 and IC2, the stronger difference between POAG and control was found with 1-300 Hz (p < 0.0001) rather than with 10-300 Hz (p < 0.0001 and p = 0.0005, respectively). For the 'oscillatory potentials' at 100-300 Hz, POAG and control differed significantly in IC1 and IC2 (p < 0.05), but not in DC (p = 0.8). However, filtering at 200-300 Hz did not show a difference between POAG and control (p > 0.5). Thus, we applied a filter setting of 1-200 Hz, which seemed to be most sensitive in detecting glaucomatous retinal dysfunction (p < 0.0001). CONCLUSIONS A filter setting of 1-200 Hz appears most sensitive to detect glaucomatous damage if using a two-global-flash mfERG: using a band-pass filter a with lower low-frequency cut-off, containing the 10 Hz component, may be especially important in the small induced components that show glaucomatous damage most sensitively. High frequencies of 100-300 Hz also contain information that differentiates glaucoma from normal and thus should be included in the analysis.
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Affiliation(s)
- Anna A Ledolter
- Department of Ophthalmology, University of Basel, Mittlere Strasse 91, 4031 Basel, Switzerland.
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The 2-global flash mfERG in glaucoma: attempting to increase sensitivity by reducing the focal flash luminance and changing filter settings. Doc Ophthalmol 2012. [DOI: 10.1007/s10633-012-9360-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lung JCY, Swann PG, Wong DSH, Chan HHL. Global flash multifocal electroretinogram: early detection of local functional changes and its correlations with optical coherence tomography and visual field tests in diabetic eyes. Doc Ophthalmol 2012; 125:123-35. [PMID: 22828871 DOI: 10.1007/s10633-012-9343-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE To investigate the correlations of the global flash multifocal electroretinogram (MOFO mfERG) with common clinical visual assessments--Humphrey perimetry and Stratus circumpapillary retinal nerve fiber layer (RNFL) thickness measurement in type II diabetic patients. METHODS Forty-two diabetic patients participated in the study: Ten were free from diabetic retinopathy (DR), while the remainder suffered from mild to moderate nonproliferative diabetic retinopathy. Fourteen age-matched controls were recruited for comparison. MOFO mfERG measurements were made under high- and low-contrast conditions. Humphrey central 30-2 perimetry and Stratus OCT circumpapillary RNFL thickness measurements were also performed. Correlations between local values of implicit time and amplitude of the mfERG components [direct component (DC) and induced component (IC)], and perimetric sensitivity and RNFL thickness were evaluated by mapping the localized responses for the three subject groups. RESULTS MOFO mfERG was superior to perimetry and RNFL assessments in showing differences between the diabetic groups (with and without DR) and the controls. All the MOFO mfERG amplitudes (except IC amplitude at high contrast) correlated better with perimetry findings (Pearson's r ranged from 0.23 to 0.36, p < 0.01) than did the mfERG implicit time at both high and low contrasts across all subject groups. No consistent correlation was found between the mfERG and RNFL assessments for any group or contrast conditions. The responses of the local MOFO mfERG correlated with local perimetric sensitivity but not with RNFL thickness. CONCLUSION Early functional changes in the diabetic retina seem to occur before morphological changes in the RNFL.
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Affiliation(s)
- J C Y Lung
- Laboratory of Experimental Optometry Neuroscience, School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China
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Chu PHW, Ng YF, To CH, So KF, Brown B, Chan HHL. Luminance-modulated adaptation in the global flash mfERG: a preliminary study of early retinal functional changes in high-risk glaucoma patients. Graefes Arch Clin Exp Ophthalmol 2011; 250:261-70. [PMID: 21881844 DOI: 10.1007/s00417-011-1790-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 07/16/2011] [Accepted: 07/28/2011] [Indexed: 10/17/2022] Open
Abstract
PURPOSE To investigate the association of the luminance-modulation global flash multifocal electroretinogram (mfERG) and other clinical assessments of vision in subsets of subjects at high risk of developing glaucomatous damage. METHODS Eighteen subjects (28 eyes) with asymmetric glaucoma and ocular hypertension were measured in this longitudinal study of visual field, OCT, and multifocal electroretinogram (mfERG). Five ophthalmic examinations were scheduled, once every 12 months over a 4-year period. The mfERG was assessed using a luminance-modulated global flash stimulation paradigm. The adaptive index which we have reported previously was calculated. RESULTS There was a significant thinning of the peripapillary retinal nerve fiber layer over the course of the study for eyes with ocular hypertension, or for fellow eyes with asymmetric glaucoma which initially had an abnormal adaptive index; such eyes showed a thinning rate of -3.59 and -3.69 μm/year, respectively. However, no significant thinning was found for eyes which initially had a normal adaptive index. Two subjects were shown to have glaucomatous damage, confirmed by abnormal thinning of the retinal nerve fiber layer and visual field loss respectively at the last visit. However, these patients had shown an abnormal adaptive index in the mfERG measurement at the first visit. CONCLUSIONS The adaptive index calculated from the measurement of luminance-modulated global flash mfERG is useful for predicting progression of signs related to glaucoma, especially in high-risk groups. The abnormal adaptive index reflects the change in fast-adaptive mechanisms in the retina and indicates the risk of developing glaucoma.
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Affiliation(s)
- Patrick H W Chu
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China
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Luo X, Patel NB, Harwerth RS, Frishman LJ. Loss of the low-frequency component of the global-flash multifocal electroretinogram in primate eyes with experimental glaucoma. Invest Ophthalmol Vis Sci 2011; 52:3792-804. [PMID: 21421870 DOI: 10.1167/iovs.10-6667] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To study relationships between glaucoma-sensitive components identified with frequency-domain analysis of global-flash multifocal electroretinogram (mfERG), regional retinal nerve fiber layer thickness (RNFLT), and local visual field sensitivity (VS). METHODS Eleven macaque monkeys, including four controls and seven with unilateral laser-induced trabecular meshwork scarification and ocular hypertension, were observed with optical coherence tomography (OCT), full-field light-adapted flash ERG, 103-hexagon global-flash mfERG (MFOFO), and static perimetry. The effects of experimental glaucoma on mfERG were assessed in the frequency domain. Relations between root mean square (RMS) amplitude of a glaucoma-sensitive frequency range and peripapillary RNFLT (standard 12° OCT circular scan), and between RMS amplitude and VS were studied. RESULTS Experimental glaucoma led to a dramatic and consistent power loss in the low-frequency (<25 Hz) band of mfERG. The RMS of this low-frequency component (LFC) correlated significantly with the regional RNFLT. The r(2) of linear fits was 0.39 (P < 0.001) for cross-sectional group data and 0.60 after correction for intersubject variability. The r(2) of linear fits for longitudinal data from individual animals was as high as 0.78 (P < 0.001). Local LFC RMS amplitude also correlated significantly with interpolated VS for hexagons. The r(2) for exponential fits of hexagon LFC RMS amplitudes (inner three rings) versus VS (dB) was 0.29 to 0.52 (P < 0.001) for the group and up to 0.95 in individuals. CONCLUSIONS The significant correlations between regional measures of global-flash mfERG, RNFLT, and VS suggest that LFC RMS amplitude provides a useful index for objective quantification of local RGC function and monitoring of early changes in glaucoma.
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Affiliation(s)
- Xunda Luo
- College of Optometry, University of Houston, Houston, Texas 77204-2020, USA
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Miguel-Jiménez J, Boquete L, Ortega S, Rodríguez-Ascariz J, Blanco R. Glaucoma detection by wavelet-based analysis of the global flash multifocal electroretinogram. Med Eng Phys 2010; 32:617-22. [DOI: 10.1016/j.medengphy.2010.02.019] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Revised: 02/20/2010] [Accepted: 02/23/2010] [Indexed: 11/28/2022]
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Effects of luminance combinations on the characteristics of the global flash multifocal electroretinogram (mfERG). Graefes Arch Clin Exp Ophthalmol 2010; 248:1117-25. [PMID: 20306071 DOI: 10.1007/s00417-010-1346-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 02/05/2010] [Accepted: 02/19/2010] [Indexed: 10/19/2022] Open
Abstract
PURPOSE This study aims to ascertain the characteristics of the response triggered by the global flash multifocal electroretinogram (MOFO mfERG) under various combinations of global and focal flash luminance, and to determine the optimal conditions for this measurement. METHODS Ten normal subjects with mean age 23.2 yrs (+/- 1.14 yrs) were recruited for the MOFO mfERG measurement. The visual stimulation consisted of four video frames (stimulus frame with 103 scaled hexagonal focal flashes, followed by a dark frame, a global flash and then another dark frame). The focal and global flash intensities were varied independently for four levels (50, 100, 200 and 400 cd/m(2)). The subjects then underwent measurements with sixteen combinations of focal and global flash luminance. The direct component (DC) and induced component (IC) of the MOFO mfERG were grouped into central and peripheral regions for analysis. RESULTS The central and peripheral DC amplitude increased with the focal flash luminance under constant global flash luminance. Moreover, the proportion of the global flash and focal flash intensity was shown to be important to achieve an optimal IC response. When the ratio of global flash luminance to focal flash luminance (g/f ratio) was kept at about 2:1, the central and peripheral IC amplitude reached the peak value, and further increasing the global flash luminance would not enhance the IC response magnitude. The implicit time of both central and peripheral DC generally decreased with the increase of g/f ratio. However, the implicit time of central and peripheral IC increased with the g/f ratio. CONCLUSION The g/f ratio is important in the MOFO mfERG paradigm, since the DC and IC responses change with this ratio. In order to obtain both optimal DC and IC responses, a g/f ratio of 1:1 with focal flash luminance between 100 cd/m(2) and 200 cd/m(2) would be recommended. As the global flash mfERG paradigm is studying the interaction triggered by both flashes, the g/f ratio is a vital parameter for measurement in future studies.
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Porcine global flash multifocal electroretinogram: Possible mechanisms for the glaucomatous changes in contrast response function. Vision Res 2008; 48:1726-1734. [DOI: 10.1016/j.visres.2008.05.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 04/09/2008] [Accepted: 05/07/2008] [Indexed: 01/08/2023]
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