1
|
Al-Nosairy KO, Rodenbeck K, Vorholt S, Djouoma N, Thieme H, Müller F, Hoffmann MB. Rapid campimetry - a novel robust kinetic approach for visual field screening in glaucoma. Front Med (Lausanne) 2024; 11:1419147. [PMID: 39156695 PMCID: PMC11327055 DOI: 10.3389/fmed.2024.1419147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 07/11/2024] [Indexed: 08/20/2024] Open
Abstract
Purpose To investigate the robustness and variability of a novel kinetic visual field (VF) screening method termed rapid campimetry (RC). Methods In RC visual field (VF) screening is enabled via kinetic-based testing on any computer (10°/4.7 s at 40-cm viewing distance) and high contrast in a dark room (1 cd/cm2). In experiment (1): 30 participants [20 healthy participants (HC), 5 glaucoma patients (GLA) and 5 patients with cataract (CAT)] were included to test the intra-session variability (fatigue effect) and the following effects on RC: room illumination (140 cd/m2), ±3 D refractive errors, media opacity. In experiment (2): Inter-session variability (1-3 weeks apart) was assessed in 10 HC and 10 GLA. Since RC detects absolute scotomas, the outcome measure was the size of physiological (blindspot) and pathological (glaucoma) scotomas in degrees. A repeated measures ANOVA was employed in experiment 1 and intraclass correlation (ICC) in experiment 2. Results Neither the size of the blindspot nor the VF defects differed significantly between the different testing conditions. For intra-session variability, the average bias of blindspot size was -0.6 ± 2.5°, limits of agreement (LOA), in comparison to 0.3 ± 1.5° for VF defects, both with ICC of 0.86 and 0.93, respectively. For the inter-session repeatability, the average bias and LOA for blindspot size was 0.2 ± 3.85° in comparison 1.6 ± 3.1° for VF defects, both with ICC of 0.87 and 0.91, respectively. Conclusion RC was robust to suboptimal testing VF conditions and showed good-to-excellent reliability between VF testing visits holding high potential for teleophthalmology.
Collapse
Affiliation(s)
- Khaldoon O. Al-Nosairy
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
| | - Katharina Rodenbeck
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
- Department of Optometry, Berlin University of Applied Sciences and Technology, Berlin, Germany
| | - Sophie Vorholt
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
| | - Nidele Djouoma
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
| | - Hagen Thieme
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
| | | | - Michael B. Hoffmann
- Department of Ophthalmology, Faculty of Medicine, Otto-von-Guericke University, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| |
Collapse
|
2
|
Amorim-de-Sousa A, Macedo-de-Araújo RJ, Fernandes P, González-Méijome JM, Queirós A. Enhancement of the Inner Foveal Response of Young Adults with Extended-Depth-of-Focus Contact Lens for Myopia Management. Vision (Basel) 2024; 8:19. [PMID: 38651440 PMCID: PMC11036275 DOI: 10.3390/vision8020019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND Myopia management contact lenses have been shown to successfully decrease the rate of eye elongation in children by changing the peripheral refractive profile of the retina. Despite the efforts of the scientific community, the retinal response mechanism to defocus is still unknown. The purpose of this study was to evaluate the local electrophysiological response of the retina with a myopia control contact lens (CL) compared to a single-vision CL of the same material. METHODS The retinal electrical activity and peripheral refraction of 16 eyes (16 subjects, 27.5 ± 5.7 years, 13 females and 3 males) with myopia between -0.75 D and -6.00 D (astigmatism < 1.00 D) were assessed with two CLs (Filcon 5B): a single-vision (SV) CL and an extended-depth-of-focus (EDOF) CL used for myopia management. The peripheral refraction was assessed with an open-field WAM-5500 auto-refractometer/keratometer in four meridians separated by 45° at 2.50 m distance. The global-flash multifocal electroretinogram (gf-mfERG) was recorded with the Reti-port/scan21 (Roland Consult) using a stimulus of 61 hexagons. The implicit time (in milliseconds) and response density (RD, in nV/deg2) of the direct (DC) and induced (IC) components were used for comparison between lenses in physiological pupil conditions. RESULTS Although the EDOF decreased both the HCVA and the LCVA (one and two lines, respectively; p < 0.003), it still allowed a good VA. The EDOF lens induced a myopic shift in most retinal areas, with a higher and statistically significant effect on the nasal retina. No differences in the implicit times of the DC and IC components were observed between SV and EDOF. Compared with the SV, the EDOF lens showed a higher RD in the IC component in the foveal region (p = 0.032). In the remaining retinal areas, the EDOF evoked lower, non-statistically significant RD in both the DC and IC components. CONCLUSIONS The EDOF myopia control CL enhanced the response of the inner layers of the fovea. This might suggest that, besides other mechanisms potentially involved, the central foveal retinal activity might be involved in the mechanism of myopia control with these lenses.
Collapse
Affiliation(s)
- Ana Amorim-de-Sousa
- Clinical and Experimental Optometry Research Lab (CEORLab), School of Science, University of Minho, 4710-057 Braga, Portugal
| | - Rute J. Macedo-de-Araújo
- Clinical and Experimental Optometry Research Lab (CEORLab), School of Science, University of Minho, 4710-057 Braga, Portugal
- Physics Center of Minho and Porto Universities (CF-UM-UP), 4710-057 Braga, Portugal
| | - Paulo Fernandes
- Clinical and Experimental Optometry Research Lab (CEORLab), School of Science, University of Minho, 4710-057 Braga, Portugal
- Physics Center of Minho and Porto Universities (CF-UM-UP), 4710-057 Braga, Portugal
| | - José M. González-Méijome
- Clinical and Experimental Optometry Research Lab (CEORLab), School of Science, University of Minho, 4710-057 Braga, Portugal
- Physics Center of Minho and Porto Universities (CF-UM-UP), 4710-057 Braga, Portugal
| | - António Queirós
- Clinical and Experimental Optometry Research Lab (CEORLab), School of Science, University of Minho, 4710-057 Braga, Portugal
- Physics Center of Minho and Porto Universities (CF-UM-UP), 4710-057 Braga, Portugal
| |
Collapse
|
3
|
Dettoraki M, Droutsas K, Lazaridis A, Moschos MM. Evaluation of macular function and morphology following accelerated collagen cross-linking in progressive keratoconus. Eur J Ophthalmol 2022; 32:2547-2553. [PMID: 35450449 DOI: 10.1177/11206721221094880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To assess any changes in macular function and morphology in patients with progressive keratoconus undergoing accelerated corneal cross-linking (CXL). METHODS This prospective case series included 9 eyes of 8 patients with progressive keratoconus undergoing CXL using a high intensity accelerated protocol (9 mW/cm2 for 14 min) with a total surface dose of 7.5 J/cm2. Visual acuity assessment, slit lamp biomicroscopy, dilated fundoscopy, corneal tomography, multifocal electroretinography (mfERG) and spectral domain optical coherence tomography scan were performed at baseline, 2 weeks and 6 weeks postoperatively. RESULTS Uncorrected and corrected distance visual acuity did not change significantly at 2 weeks and 6 weeks following accelerated CXL compared to baseline. Retinal response density (RRD) of mfERG significantly decreased at 2 weeks postoperatively compared to baseline (p = 0.008) but did not differ from the baseline value at 6 weeks postoperatively in the fovea (ring 1) (p = 0.95). Similarly, P1 latency significantly decreased at 2 weeks (p = 0.04) but did not change at 6 weeks (p = 1.00) postoperatively compared to baseline in the fovea. No changes in RRD or P1 latency were observed in the retinal rings surrounding the fovea (rings 2 to 5). Central foveal thickness did not change at 2 weeks and 6 weeks postoperatively compared to baseline (p = 0.53 and p = 0.93, respectively). CONCLUSIONS A short-term reversible decrease in macular electrical activity without any structural changes seems to occur after accelerated CXL in patients with progressive keratoconus. The return of macular response to the preoperative values shows the safety of the CXL protocol.
Collapse
Affiliation(s)
- M Dettoraki
- First Department of Ophthalmology, Medical School, 393206National and Kapodistrian University of Athens, Athens, Greece
| | - K Droutsas
- First Department of Ophthalmology, Medical School, 393206National and Kapodistrian University of Athens, Athens, Greece.,Department of Ophthalmology, 98594Philipps University of Marburg, Marburg, Germany
| | - A Lazaridis
- Department of Ophthalmology, 98594Philipps University of Marburg, Marburg, Germany
| | - M M Moschos
- First Department of Ophthalmology, Medical School, 393206National and Kapodistrian University of Athens, Athens, Greece
| |
Collapse
|
4
|
Panorgias A, Aigbe S, Jeong E, Otero C, Bex PJ, Vera-Diaz FA. Retinal Responses to Simulated Optical Blur Using a Novel Dead Leaves ERG Stimulus. Invest Ophthalmol Vis Sci 2021; 62:1. [PMID: 34338749 PMCID: PMC8340654 DOI: 10.1167/iovs.62.10.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose The purpose of this study was to evaluate retinal responses to different types and magnitudes of simulated optical blur presented at specific retinal eccentricities using naturalistic images. Methods Electroretinograms (ERGs) were recorded from 27 adults using 30-degree dead leaves naturalistic images, digitally blurred with one of three types of optical blur (defocus, astigmatism, and spherical aberrations), and one of three magnitudes (0.1, 0.3, or 0.5 µm) of blur. Digitally computed blur was applied to the entire image, or on an area outside the central 6 degrees or 12 degrees of retinal eccentricity. Results ERGs were significantly affected by blur type, magnitude, and retinal eccentricity. ERGs were differentially affected by defocus and spherical aberrations; however, astigmatism had no effect on the ERGs. When blur was applied only beyond the central 12 degrees eccentricity, the ERGs were unaffected. However, when blur was applied outside the central 6 degrees, the ERG responses were significantly reduced and were no different from the ERGs recorded with entirely blurred images. Conclusions Blur type, magnitude, and location all affect the retinal responses. Our data indicate that the retinal area between 6 and 12 degrees eccentricity has the largest effect on the retinal responses to blur. In addition, certain optical blur types appear to have a more detrimental effect on the ERGs than others. These results cannot be solely explained by changes to image contrast and spatial frequency content, suggesting that retinal neurons might be sensitive to spatial cues in order to differentiate between different blur types.
Collapse
Affiliation(s)
| | - Stephanie Aigbe
- New England College of Optometry, Boston, Massachusetts, United States
| | - Emily Jeong
- New England College of Optometry, Boston, Massachusetts, United States
| | - Carles Otero
- EMEA Scientific Communications - Alcon, Barcelona, Cataluña, Spain
| | - Peter J Bex
- New England College of Optometry, Boston, Massachusetts, United States.,Psychology Department, College of Science, Northeastern University, Boston, Massachusetts, United States
| | | |
Collapse
|
5
|
Amorim-de-Sousa A, Macedo-de-Araújo R, Fernandes P, Queirós A, González-Méijome JM. Multifocal Electroretinogram in Keratoconus Patients without and with Scleral Lenses. Curr Eye Res 2021; 46:1732-1741. [PMID: 33823736 DOI: 10.1080/02713683.2021.1912781] [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] [Indexed: 10/21/2022]
Abstract
Purpose: To investigate changes in the multifocal electroretinogram (mfERG) response in eyes with keratoconus when corrected with scleral lenses (SL) compared with the best correction in glasses.Methods: The mfERG responses in 10 eyes with keratoconus were recorded with the best correction using both a trial frame (baseline) and a hexafocon A SL using an electrophysiological diagnostic system. Electrophysiologic measurements were performed with the pupils fully dilated with instillation of 1% phenylephrine. The implicit time (milliseconds), amplitude (nV), and response density (nV/deg2) of the peaks (N1, P1, and N2) were analyzed for the total mfERG response, six rings and four quadrants of the retina, and compared between the two conditions.Results: All eyes had a significant improvement in visual quality with the SL compared with baseline (mean differences, 0.26 ± 0.17 and 0.22 ± 0.13 logarithm of the minimum angle of resolution for high- and low-contrast visual acuity, respectively). The peaks implicit times of the mfERG responses did not show significant differences (p > .05). The P1 amplitude decreased in all the retinal areas with the SL. Only the total retinal response and the nasal quadrants reached significance (p ≤ 0.044). The P1 response density in ring 1 was on average higher with the SL, but not significantly so. The decline in P1 response density from the center to the periphery was more abrupt with the SL, and was more similar to the response density distribution of a typical subject, without a corneal pathology.Conclusions: mfERG did not show any change associated with retinal disease in young patients with keratoconus. Although the improved visual performance was not associated with changes in the mfERG response, the correction of irregular astigmatism with the SL helps exclude the optical effect induced by keratoconus.
Collapse
Affiliation(s)
- Ana Amorim-de-Sousa
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - Rute Macedo-de-Araújo
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - Paulo Fernandes
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - António Queirós
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| | - José M González-Méijome
- Clinical & Experimental Optometry Research Lab (CEORLab), Center of Physics, University of Minho, Braga, Portugal
| |
Collapse
|
6
|
Chan HL, Siu AW. Effect of optical defocus on multifocal ERG responses. Clin Exp Optom 2021; 86:317-22. [PMID: 14558853 DOI: 10.1111/j.1444-0938.2003.tb03127.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2002] [Revised: 04/07/2003] [Accepted: 04/25/2003] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Multifocal electroretinography (mfERG) is a sensitive technique to probe retinal function topographically. Various conditions such as macular degeneration decrease the first-order kernel (K1) response magnitude of mfERG. Previous studies have given inconsistent results on the effect of optical defocus due to poor controls. This study investigated the effect of optical defocus on the K1 response of the central retina using a well-controlled method. METHODS Twenty subjects were recruited to undergo mfERG measurement using the VERIS 4.0 system. A four millimetre artificial pupil was fitted before each fully-dilated right eye, optically corrected for the viewing distance. The implicit times and response amplitudes of n1 (first negative trough) and p1 (first positive peak) under three different optical defocus conditions (zero dioptres, +1.00 D and +3.00 D) were measured. RESULTS The implicit times of n1 and p1 did not demonstrate any significant variation from the central macula to para-macula under different optical defocus conditions. The response amplitude of n1 did not show any changes from the central macula to para-macula but the response amplitude of the central macular p1 showed a significant reduction by 12 per cent under +1.00 D defocus and +3.00 D defocus. CONCLUSIONS Optical defocus causes mild reduction in mfERG at the central macula but there are no significant changes in the periphery. A full optical correction is recommended for mfERG measurement to minimise the reduction of the macular response due to optical defocus.
Collapse
Affiliation(s)
- Ho-Lung Chan
- Department of Optometry and Radiography, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR, China
| | | |
Collapse
|
7
|
Revisiting the Safety of the Corneal Collagen Crosslinking Procedure: Evaluation of the Effect of Ultraviolet A Radiation on Retinal Function and Structure. Cornea 2019; 39:237-244. [DOI: 10.1097/ico.0000000000002157] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
8
|
Herbik A, Geringswald F, Thieme H, Pollmann S, Hoffmann MB. Prediction of higher visual function in macular degeneration with multifocal electroretinogram and multifocal visual evoked potential. Ophthalmic Physiol Opt 2014; 34:540-51. [PMID: 25160891 DOI: 10.1111/opo.12152] [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] [Received: 01/20/2014] [Accepted: 07/17/2014] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Visual search can be guided by past experience of regularities in our visual environment. This search guidance by contextual memory cues is impaired by foveal vision loss. Here we compared retinal and cortical visually evoked responses in their predictive value for contextual cueing impairment and visual acuity. METHODS Multifocal electroretinograms to flash stimulation (mfERGs; 103 locations; 55.8° diameter) and visual evoked potentials to pattern-reversal stimulation (mfVEPs; 60 locations; 48.6° diameter) were recorded monocularly in participants with age-related macular degeneration (n = 14 and 16, respectively). Response magnitudes were calculated as the respective signal-to-noise ratios for each eccentricity. Visual acuities (logMAR, range: 0.0-1.2) and contextual cueing effects on visual search (reaction time gain, range: -0.14-0.15) were correlated with the signal-to-noise ratios. A step-wise regression analysis was applied separately to the mfERG- and mfVEP-dataset to determine the eccentricity range and the processing stage that is critical for these visual functions. RESULTS Central mfERGs (1.0-3.2°) were the sole predictor of contextual cueing of visual search (p = 0.006), but they were not significant predictors of visual acuity. In contrast, central mfVEPs (1.3-3.2°) were the sole predictor of visual acuity (p < 0.001), but they were not significant predictors of contextual cueing. CONCLUSIONS Contextual cueing is more dependent on parafoveal mfERG magnitude while visual acuity is more dependent on parafoveal mfVEP magnitude. The relation of contextual cueing to parafoveal mfERG magnitudes indicates the predictive value of retinal bipolar cell activity for this advanced level of visual function.
Collapse
Affiliation(s)
- Anne Herbik
- Department of Ophthalmology, Otto-von-Guericke University, Magdeburg, Germany
| | | | | | | | | |
Collapse
|
9
|
Nakamura M, Kato K, Kamata S, Ishikawa K, Nagai T. Effect of refractive errors on multifocal VEP responses and standard automated perimetry tests in a single population. Doc Ophthalmol 2014; 128:179-89. [DOI: 10.1007/s10633-014-9431-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Accepted: 03/03/2014] [Indexed: 11/24/2022]
|
10
|
Bach M, Poloschek CM. Electrophysiology and glaucoma: current status and future challenges. Cell Tissue Res 2013; 353:287-96. [PMID: 23525754 DOI: 10.1007/s00441-013-1598-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/21/2013] [Indexed: 11/25/2022]
Abstract
Visual electrophysiology allows non-invasive monitoring of the function of most processing stages along the visual pathway. Here, we consider which of the available methods provides the most information concerning glaucomatous optic nerve disease. The multifocal electroretinogram (ERG), although often employed, is less affected in glaucoma than two direct measurements of retinal ganglion cell function, namely the pattern ERG (PERG) and the photopic negative response (PhNR) of the ERG. For the PERG, longitudinal studies have been reported, suggesting that this method can be used for the early detection of glaucoma; for the PhNR, no longitudinal study is available as yet. The multifocal PERG can spatially resolve ganglion cell function but its glaucomatous reduction is typically panretinal, even with only local field changes and so, its topographic resolution is of no advantage in glaucoma. The multifocal visual evoked potential promises objective perimetry and shows sensitivity and specificity comparable with standard automated perimetry but has not been established as a routine tool to date.
Collapse
Affiliation(s)
- Michael Bach
- Section Visual Function, Department of Ophthalmology, University of Freiburg, Freiburg, Germany.
| | | |
Collapse
|
11
|
Herbik A, Hölzl GC, Reupsch J, Hoffmann MB. Differential effects of optic media opacities on mfERGs and mfVEPs. Clin Neurophysiol 2013; 124:1225-31. [PMID: 23352815 DOI: 10.1016/j.clinph.2012.11.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 11/21/2012] [Accepted: 11/28/2012] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To assess different effects of image degradation that could result from optic media opacities on multifocal retinal (mfERG) and cortical responses (mfVEP). METHODS Monocular flash-mfERGs and pattern-reversal mfVEPs were recorded. MfERG-P1 amplitudes and implicit times and mfVEP root-mean-square values (RMS) and delays were compared for different filter conditions (none, 8% luminance, 50% luminance, 50% luminance plus blur) in a total of ten participants with normal vision. RESULTS Reducing stimulus luminance down to 50% and 8% reduced mfERG amplitudes to 86% and 42%, respectively, with no significant effect on mfVEP amplitude. Implicit times were increased for mfERGs by 0.9 ms and 6.0 ms, respectively, and for mfVEPs by 1.0 ms and 6.3 ms, respectively. For '50% luminance plus blur' mfERG amplitudes were significantly reduced centrally and enhanced peripherally and delayed by 1.3 ms. MfVEPs were reduced close to noise level independent of eccentricity. CONCLUSIONS Degradation of the retinal image is a potential source of discrepancies between mfERGs and mfVEPs. Image blur suppresses the mfVEP at all locations and changes mfERG topography, resulting in a selective loss of central responses. SIGNIFICANCE Considering optic media opacities is of importance for the correct interpretation of mfERG and mfVEP recordings, particularly in elderly patients.
Collapse
Affiliation(s)
- A Herbik
- Visual Processing Laboratory, Ophthalmology, Otto-von-Guericke-University, Magdeburg, Germany
| | | | | | | |
Collapse
|
12
|
Accommodation limits induced optical defocus in defocus experiments. Doc Ophthalmol 2010; 121:103-9. [DOI: 10.1007/s10633-010-9237-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2007] [Accepted: 05/31/2010] [Indexed: 10/19/2022]
|
13
|
Topographical alterations of inner retinal activity during systemic hyperoxia-hypercapnia in normal subjects and patients with type 1 diabetes. Doc Ophthalmol 2010; 120:229-41. [PMID: 20099007 DOI: 10.1007/s10633-010-9217-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 01/10/2010] [Indexed: 10/19/2022]
Abstract
The purpose of this study was to investigate whether an increase in the circulating oxygen supply can alter inner retinal function, assessed by recordings of multifocal oscillatory potentials. We studied 9 subjects with type 1 diabetes (8 without overt retinopathy, one with 2 microaneurysms) and 10 similar-aged normal subjects. The central 60 degrees of the retina was stimulated by an array of 61 hexagonal elements, and mfOP recordings were obtained while breathing room air or carbogen. First-order kernel analysis of the recordings shows 2 potentials (first-order OP1, OP2), whereas second-order kernel analysis produces 3 potentials (second-order OP1, OP2, OP3). Two methods were used to analyze the results: First, we performed a ring analysis for each subject and measured the amplitudes and latencies of the five potentials. We demonstrate that during carbogen inhalation, the control subjects, but not the patients with diabetes, showed significantly increased second-order OP3 amplitudes, for a retinal ring from around 1.8-13 degrees eccentricity. Secondly, a topographical analysis was performed on the amplitude of the second-order OP3 in all 61 traces (from the average recordings of each subject group), which revealed significant alterations not visible in a ring analysis. A similar topographical analysis of the amplitude of the first-order OP2 revealed a small increase in its amplitude during carbogen inhalation for both subject groups. This study demonstrates that some aspects of inner retinal function are modified by the inhalation of carbogen. The reduced effect of carbogen inhalation on the recordings from the patients with diabetes may be due to compromised vascular perfusion in these subjects.
Collapse
|
14
|
Poloschek CM, Bach M. Can we do without mydriasis in multifocal ERG recordings? Doc Ophthalmol 2008; 118:121-7. [DOI: 10.1007/s10633-008-9146-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2007] [Revised: 06/29/2008] [Accepted: 08/11/2008] [Indexed: 12/01/2022]
|
15
|
Hansen RM, Moskowitz A, Fulton AB. Multifocal ERG responses in infants. Invest Ophthalmol Vis Sci 2008; 50:470-5. [PMID: 18719077 DOI: 10.1167/iovs.08-2429] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To assess function of the central retina in 10-week-old infants, multifocal electroretinograms (mfERGs) were recorded. mfERG responses represent postreceptor retinal activity. METHODS In infants (n = 23) and adults (n = 10), mfERG responses to both unscaled and scaled 61 hexagon arrays were recorded. Amplitude and implicit time of negative (N(1), N(2)) and positive (P(1)) peaks of the first-order kernel were examined. The response from the entire area stimulated and responses to concentric rings were analyzed separately. The overall averaged response of the first slice of the second-order kernel was also evaluated. Results from infants and adults were compared. RESULTS Amplitudes of the infants' responses (N(1), P(1), N(2)) were significantly smaller and implicit times were significantly longer than those of adults. In infants, amplitude and implicit time varied little with eccentricity. In adults, amplitude decreased with eccentricity, whereas implicit time varied little. In infants, the second-order kernel was relatively more attenuated than the first-order kernel. CONCLUSIONS The infants' mfERG responses indicated immaturities of processing in the central retina. Infant-adult differences in the distribution of cones and bipolar cells may account for the results.
Collapse
Affiliation(s)
- Ronald M Hansen
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
| | | | | |
Collapse
|
16
|
Lai TYY, Chan WM, Lai RYK, Ngai JWS, Li H, Lam DSC. The clinical applications of multifocal electroretinography: a systematic review. Surv Ophthalmol 2007; 52:61-96. [PMID: 17212991 DOI: 10.1016/j.survophthal.2006.10.005] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Multifocal electroretinography (mfERG) is an investigation that can simultaneously measure multiple electroretinographic responses at different retinal locations by cross-correlation techniques. mfERG therefore allows topographic mapping of retinal function in the central 40-50 degrees of the retina. The strength of mfERG lies in its ability to provide objective assessment of the central retinal function at different retinal areas within a short duration of time. Since the introduction of mfERG in 1992, mfERG has been applied in a large variety of clinical settings. This article reviews the clinical applications of mfERG based on the currently available evidence. mfERG has been found to be useful in the assessment of localized retinal dysfunction caused by various acquired or hereditary retinal disorders. The use of mfERG also enabled clinicians to objectively monitor the treatment outcomes as the changes in visual functions might not be reflected by subjective methods of assessment. By changing the stimulus, recording, and analysis parameters, investigation of specific retinal electrophysiological components can be performed topographically. Further developments and consolidations of these parameters will likely broaden the use of mfERG in the clinical setting.
Collapse
Affiliation(s)
- Timothy Y Y Lai
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | | | | | | | | | | |
Collapse
|
17
|
Palmowski-Wolfe AM, Perez MT, Behnke S, Fuss G, Martziniak M, Ruprecht KW. Influence of Dopamine Deficiency in Early Parkinson’s Disease on the Slow Stimulation Multifocal-ERG. Doc Ophthalmol 2006; 112:209-15. [PMID: 16791744 DOI: 10.1007/s10633-006-0008-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE In animal studies intravitreal injection of tetrodotoxin (TTX) results in mfERG waveform changes similar to those observed in glaucoma. As TTX blocks amacrine as well as ganglion cells, there is still a question regarding the underlying cell population responsible for these changes in waveform. In an attempt to assess the contribution of the amacrine cells to these changes, a mfERG was obtained from patients with Parkinson's disease as some amacrine cells are mediated by dopamine, a substance lacking in Parkinson's. METHODS Eight patients with early Parkinson's disease underwent ophthalmologic examination, testing of contrast sensitivity and electrophysiological examination according to ISCEV standard at least 12 h following their last medication with Dopamine. A slow stimulation mfERG was obtained with a stimulus base interval of 53.3 ms and with a stimulus base interval of 106.6 ms. During MF-ERG recordings 103 hexagons stimulated the central 50 deg of the retina simultaneously and independently (m-sequence 2(13), L(max): 200 cd/m(2), approximately 100% contrast). RESULTS Contrast sensitivity and ISCEV standard electrophysiological testing was unremarkable. When the mfERG was analyzed, only four patients had an adequate signal-to-noise ratio to allow further data analysis - one of whom was diagnosed with a multi system atrophy in retrospect. The first order response component was analyzed at a filter setting of 10-300 Hz and at 100-300 Hz (OPs) and compared to mfERGs of a control group. On average, in patients, the amplitude of N1P1 was slightly lower in the central and nasal response averages. When the three OPs at a latency of 72-89 ms were analyzed in the 53.3 ms base interval recording, the most marked difference in amplitude was observed in the superior nasal response average of the first OP. Here a mean amplitude of 1.3 nV/deg(2) in patients compared to a mean amplitude of 1.9 nV/deg(2) in the control group (P: 0.08). DISCUSSION In contrast to our previous findings in NTG, there was a consistent presence of three OPs. Under the stimulus conditions applied, we did not find an influence of dopaminergic amacrine cells on the mfERG in our patients with moderate stages of Parkinsion's. The difficulties in obtaining an adequate signal-to noise ratio due to e.g. muscle artifacts even in Parkinson patients of moderate disease stages render a success of mfERG recording in patients with more advanced stages unlikely. The question of the influence of dopaminergic amacrine cells on the mfERG could possibly be addressed using MPDT in animal research.
Collapse
|
18
|
Palmowski-Wolfe AM, Allgayer RJ, Vernaleken B, Schötzau A, Ruprecht KW. Slow-stimulated multifocal ERG in high- and normal-tension glaucoma. Doc Ophthalmol 2006; 112:157-68. [PMID: 16786253 DOI: 10.1007/s10633-006-0007-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To study the ability and sensitivity of the slow stimulation multifocal ERG (mfERG) to detect glaucomatous damage. METHODS Right eyes of 20 patients with normal-tension glaucoma (NTG), 15 patients with high-tension glaucoma (HTG) and 15 healthy volunteers underwent testing with the mfERG (VERIS 4.1). The central 50 degrees of the retina were stimulated by 103 hexagons (m-sequence: 2(13)-1, Lmax: 100 cd/m(2), Lmin: 1 cd/m(2), background: 50 cd/m(2)). Each m-sequence step was followed by 3 black frames (Lmax: < 1 cd/m(2)). Five response averages of the first order response component (KI) were analyzed: the central 7.5 degrees and the 4 adjoining quadrants. The amplitudes from the first minimum, N1, to the first maximum, P1, and from P1 to the second minimum, N2, were analyzed as well as the latencies of N1, P1, N2 and the latencies of 3 multifocal oscillatory potentials (mfOPs) with their maxima at about 73, 80 and 85 ms. RESULTS For each parameter the percentage of deviation from the mean of the control group was calculated. These values were then added for each individual to form a deviation index (DI). Seventeen patients (85.0%) with NTG and 3 patients (20.0%) with HTG showed a DI outside the normal range. The major changes were observed in the mfOPs of the NTG patients. MfOPs were then selectively filtered at 100-300 Hz and their scalar product was analyzed over an epoch of 68-105 ms. This confirmed that mfOPs differed significantly from the control in the central 7.5 degrees and, for NTG, in the nasal field. With a logistic regression analysis the mfOPs had a sensitivity to differentiate 85% of the NTG patients and 73% of the HTG patients from normal. CONCLUSIONS Under these conditions, the slow-stimulated mfERG can detect glaucomatous dysfunction in NTG (85.0%). The differences observed between NTG and HTG are in support of a different underlying pathomechanism.
Collapse
|
19
|
Palmowski-Wolfe AM, Woerdehoff U. A Comparison of the Fast Stimulation Multifocal-ERG in Patients with an IOL and Control Groups of Different Age. Doc Ophthalmol 2006; 111:87-93. [PMID: 16514490 DOI: 10.1007/s10633-005-4506-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/26/2005] [Indexed: 11/30/2022]
Abstract
PURPOSE It has been shown that a cataract significantly reduces mfERG responses in the central 4-14 degrees . Removing the cataract, leads to a significant increase in the response of the central 4 degrees . In this study we compare the mfERG of Woerdehoff et al.'s patients' [Doc Ophthalmol 2004; 108(1): 67-75] following cataract surgery to a healthy control group in order to assess whether, in the elderly, further influences of age need to be considered in addition to optical effects. METHODS Eighteen patients with an IOL following cataract surgery and 29 healthy volunteers (without clouding of the media or retinal changes) underwent testing of the mfERG (103 hexagons stimulating the central 50 degrees , M-sequence 2(15), Lmax: 200 cd/m2, Lmin<1 cd/m2). For the first order response component we compared the latencies of N1,P1 and N2 as well as the natural logarithm (ln) of the amplitudes N1P1 and P1N2 for four group averages: I. the central 4 degrees, II. 4-7 degrees, III. 7-10 degrees and IV. 10-15 degrees. RESULTS Mean age was 67 years (SD 10.1) for the IOL patients, 28.5 years (SD 5.6) for a young group of controls (n=15) and 60.2 years (SD 9.2) for the older control group (n=14). Patients with an IOL did not differ in latency from either control group (ANOVA, Tukey). Interestingly, at 10-15 degrees eccentricity, the latency of N2 differed significantly between the younger (41.4 ms, SD 1.4) and the older (43.0 ms, SD 1.9) control group. In the central 4 degrees LnN1P1 amplitudes were significantly lower in the IOL group (mean: 3.7, SD 0.2) than either the younger (mean: 3.9, SD 3.3) or the older (mean: 4.0, SD 0.3) control group. In all other amplitude measures, the older control group had slightly larger mean amplitudes than the younger control group and significantly larger amplitudes than the patients with an IOL, whose amplitudes were lowest. DISCUSSION Both, primarily optical but also neural phenomena have been described to affect the mfERG changes observed with age. Our results, are in support of this, as the improvement of the mfERG response following cataract surgery does not seem to reach the level of a healthy control group of equal age. Thus, our results suggest, that a control group with an IOL should be used when retinal function is tested in subjects with an IOL.
Collapse
|
20
|
Shahidullah M, Chan HHL, Yap MK, Liu Q, To CH. Multifocal electroretinography in isolated arterially perfused bovine eye. Ophthalmic Physiol Opt 2005; 25:27-34. [PMID: 15649180 DOI: 10.1111/j.1475-1313.2004.00241.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM To develop an isolated arterially perfused bovine eye as an in vitro model for studying retinal electrophysiology using multifocal electroretinography (mfERG). METHODS Fresh bovine eyes were cannulated through the ophthalmic artery and perfused with oxygenated Krebs' solution at 37 degrees C within 15 min postmortem. Multifocal ERG was recorded using the veris 1.0 (Visual Evoked Response Imaging System). RESULTS The mfERG waveform of in vitro bovine eyes had a typical trough (negative wave, N1) and peak (positive wave, P1) similar to those of human mfERG. The implicit times (peak latencies) for N1 and P1 were 20 and 42 ms respectively, and the average response amplitude (N1P1) was 55 nV. The implicit times of N1 and P1 were maintained for more than 4 h. The mfERG responses were affected proportionately by the stimulus intensity. Without a neutral density filter, the mean response amplitude was about 55 nV, which was diminished to 26, 18 and 10 nV under neutral density filters of 0.4, 1.0 and 1.4, respectively. Partial occlusion of the pupil completely abolished mfERG responses from the corresponding part of the retina. CONCLUSIONS Isolated arterially perfused bovine eye may be used as an experimental model to study retinal electrophysiology using mfERG. The in vitro eye may offer a convenient and easily obtainable alternative to live animals, particularly for drug screening and invasive studies.
Collapse
Affiliation(s)
- Mohammad Shahidullah
- Department of Optometry and Radiography, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | | | | | | | | |
Collapse
|
21
|
Pieh C, Hoffmann MB, Bach M. The influence of defocus on multifocal visual evoked potentials. Graefes Arch Clin Exp Ophthalmol 2004; 243:38-42. [PMID: 15660277 DOI: 10.1007/s00417-004-0969-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 05/19/2004] [Accepted: 06/11/2004] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND In order to assess the influence of optical factors on the multifocal visual evoked potential (mfVEP), we obtained mfVEPs with optimal refraction and compared them to recordings with various degrees of dioptrical defocus. METHODS Monocular mfVEPs were recorded from the right eye in eight normal subjects. Dartboard stimuli with 60 sectors arranged in six concentric annuli spanning 60 degrees were generated with a VERIS system and presented on a computer monitor. Two pairs of electrodes were placed 3 cm above and below and 3 cm to the right and left of the inion. Two sets of mfVEP records per subject were obtained, one with best-corrected visual acuity and another when the stimulus was defocused by +1.0, +2.0 or +3.0 D. A signal-to-noise ratio (SNR) measure was calculated for every response from the two channels. RESULTS The effect of defocus depended on eccentricity: when defocus was at +2.0 D and higher, reducing visual acuity to <0.3, the central mfVEP responses were reduced to approximately 60%, while defocus had no marked effect at eccentricities >7 degrees. CONCLUSIONS The results suggest that, in contrast to the mfERG, the mfVEP requires optimal refraction to correctly assess the cortical responses.
Collapse
Affiliation(s)
- Christina Pieh
- Sektion Funktionelle Sehforschung, Universitäts-Augenklinik, Killianstrasse 5, 79106 Freiburg, Germany
| | | | | |
Collapse
|
22
|
Vrabec TR, Affel EL, Gaughan JP, Foroozan R, Tennant MTS, Klancnik JM, Jordan CS, Savino PJ. Voluntary suppression of the multifocal electroretinogram. Ophthalmology 2004; 111:169-76. [PMID: 14711730 DOI: 10.1016/j.ophtha.2003.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Accepted: 04/04/2003] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE To describe multifocal electroretinogram (mfERG) responses in 2 patients with nonorganic visual loss and in 11 eyes of 6 healthy persons who suppressed their mfERG responses. DESIGN Observational case series. METHODS The mfERG results were recorded in all individuals using the Veris Science 4.2 instrument. All subjects were instructed to adjust the hexagonal test pattern so that it was in best focus. A second mfERG was recorded subsequently in volunteers who attempted suppression with inattention and poor fixation and by adjusting the focus to greatest blur. MAIN OUTCOME MEASURES Amplitude and latency of mfERG responses. RESULTS Suppressed mfERGs in patients with nonorganic visual loss and healthy volunteers demonstrated reduced amplitude, especially centrally. Amplitude reduction was statistically significant in the postsuppression as compared with the presuppression recordings in wave forms N1 and N2. Statistically significant shortening of postsuppression implicit times of P1 and N2 waveforms also was demonstrated. CONCLUSIONS The mfERG responses may be suppressed voluntarily. Amplitude may be reduced. In contrast to most reported pathologic conditions, the implicit time is shortened.
Collapse
Affiliation(s)
- Tamara R Vrabec
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
INTRODUCTION The first-order kernel response of multifocal electroretinogram (mfERG) decreases in myopia. A recent study indicates that the flash ERG is also reduced with increased axial length. The aim of this study was to investigate the variations in the first-order response (K1) and the first slice of second-order response (K2.1) across the retina for different axial lengths. METHODS Thirty healthy subjects with axial length from 23.72 to 28.13 mm (spherical equivalent refractive errors from plano to -10.50 D) were recruited for mfERG measurement using VERIS 4.0. All subjects were fully corrected after cycloplegic refraction and pupils were dilated prior to mfERG recording. There is one trough, n1, and one peak, p1, in the K1 response and three troughs, n1, n2, n3, and three peaks, p1, p2, p3, in the K2.1 response. The amplitudes and implicit times of K1 and K2.1 responses were analysed to determine the characteristic of the responses across retina and the correlation to axial length. RESULTS The amplitudes of p1 (in the first-order kernel-K1) decreased in the central region and the paracentral region (ring 3) as the axial length increased. The central retinal region showed high rates of reduction in both n1 and p1 (in K1). The amplitudes of n1p1 and n2p2 (in the first slice of the second-order kernel-K2.1) were reduced in the paracentral region (from ring 2 to ring 5) as axial length increased. The average n1 and p1 in K1, and n1p1 and n2p2 in K2.1 mfERG responses are decreased in amplitude by 6-10% per millimetre elongation of axial length. CONCLUSION Eyes with longer axial lengths, usually with high myopia, have a weaker mfERG response and this attenuation is across the measured retina (from central to paracentral regions) but different kernel responses show a different pattern of attenuation at different retinal eccentricities. The weaker mfERG responses may be related to the morphological changes associated with increased axial length.
Collapse
Affiliation(s)
- H L Chan
- Department of Optometry and Radiography, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR, China.
| | | |
Collapse
|
24
|
Palmowski AM, Allgayer R, Heinemann-Vernaleken B, Scherer V, Ruprecht KW. Detection of retinal dysfunction in vitelliform macular dystrophy using the multifocal ERG (MF-ERG). Doc Ophthalmol 2003; 106:145-52. [PMID: 12678279 DOI: 10.1023/a:1022550008074] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Vitelliform macular dystrophy (VMD) is widely known for an abnormal EOG in the presence of a normal ERG. In this study the multifocal electroretinogram (MF-ERG) is described as an additional tool to detect retinal dysfunction in VMD. Three patients aged 30, 37 and 59 years with VMD and a visual acuity of OD: 0.4; OS 0.05 (patient 1), 1.25 OU (patient 2) and OU: 0.6 (patient 3) underwent additional electrophysiological testing with the MF-ERG. A multifocal-ERG of the central 50 degrees of the retina was obtained using the VERIS-system. During recording 103 hexagons flickered according to a binary m-sequence of 2(15). Mean luminance was 100 cd/m2, contrast was set at 99%. The MF-ERG recordings were compared to age matched control groups. In all three patients the MF-ERG of the central 6 degrees showed reduced amplitudes for N1P1 (first negative peak to first positive peak) and for P1N2 (P1 to the second negative peak). Implicit times were not affected. Therefore the MF-ERG can detect focal retinal dysfunction in VMD which would not be apparent in the summed retinal response recorded with the ganzfeld ERG. In contrast to other diseases, amplitudes rather than implicit times seem to be affected in the MF-ERG of vitelliform macular dystrophy.
Collapse
Affiliation(s)
- Anja M Palmowski
- Augenklinik und Poliklinik, University of the Saarland, Kirrberger Strasse 1, D 66421 Homburg/Saar, Germany.
| | | | | | | | | |
Collapse
|