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Huchzermeyer C, Kremers J. Selective Stimulation of the Different Photoreceptor Classes by Silent Substitution in Psychophysical and Electroretinographic Measurements. Klin Monbl Augenheilkd 2022; 239:1433-1439. [PMID: 36493763 DOI: 10.1055/a-1937-9901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The silent substitution technique allows creating photoreceptor-selective stimuli for psychophysical and electrophysiological tests. In contrast to other techniques, the purpose of silent substitution is not to make the targeted photoreceptor type more sensitive in comparison to the other types, but to make the stimulus invisible ("silent") to the other photoreceptor types. This allows selectivity independent of the retinal state of adaptation and enables comparing photoreceptor types under identical conditions. The foundations of these techniques will be explained in this paper. Furthermore, the importance of postreceptoral processing for the perception of photoreceptor-selective stimuli is discussed here. Although this technique is currently only available in specialized vision science labs, there is an enormous potential for clinical application.
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Affiliation(s)
- Cord Huchzermeyer
- Augenklinik mit Poliklinik, Universitätsklinikum Erlangen, Deutschland
| | - Jan Kremers
- Augenklinik mit Poliklinik, Universitätsklinikum Erlangen, Deutschland
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Aher AJ, Horn FK, Huchzermeyer C, Lämmer R, Kremers J. Responses of Postreceptoral Pathways Elicited by L- and M-Cone Isolating ON- and OFF-Electroretinograms in Glaucoma Patients. Invest Ophthalmol Vis Sci 2021; 62:14. [PMID: 34241626 PMCID: PMC8287051 DOI: 10.1167/iovs.62.9.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare the electroretinographical (ERG) responses elicited by L- and M-cone isolating ON- and OFF-sawtooth stimuli in normal subjects and glaucoma patients. Methods Twenty-one normal subjects and 44 primary open-angle glaucoma patients participated in the study. L- and M-cone isolating (18% cone contrast; 284 cd/m2) rapid ON- and rapid OFF-sawtooth (4 Hz) stimuli with two stimulus sizes (full-field (FF) and central 70° diameter) were generated using the triple silent substitution technique. ON- and OFF-response asymmetries were studied by adding the two (to obtain L-add and M-add responses). The initial positive (P) and subsequent late negative (LN) components of the L-add and M-add ERGs were compared between the subject groups and correlated with retinal nerve fiber layer thickness (RNFLT) and pattern ERG responses. Results The responses to L-ON and to M-OFF stimuli and vice versa resembled each other particularly with 70° stimuli. The PL-add amplitudes were not significantly different between the normal subjects and glaucoma patients, whereas the LNL-add amplitude was significantly (P < 0.01) smaller in the glaucoma patients. Both PM-add and LNM-add were not significantly different between the subject groups. The PERG amplitude with 0.8° check sizes and the 0.8°/16° amplitude ratio (PERG ratio) were significantly (P < 0.05) different between the subject groups. The 70° LNL-add amplitude and the 0.8° PERG amplitude were significantly correlated with RNFLT. Conclusions The ERGs to 70° cone isolating sawtooth stimuli reflect cone opponency. The cone opponent ERG responses were not significantly different between glaucoma patients and normal subjects. Luminance driven L-add responses were significantly different, indicating that central luminance signals are mainly affected in glaucoma.
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Affiliation(s)
- Avinash J Aher
- Section for Retinal Physiology, University Hospital Erlangen, Erlangen, Germany
| | - Folkert K Horn
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - Cord Huchzermeyer
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - Robert Lämmer
- Department of Ophthalmology, University Hospital Erlangen, Erlangen, Germany
| | - Jan Kremers
- Section for Retinal Physiology, University Hospital Erlangen, Erlangen, Germany.,School of Optometry and Vision Science, University of Bradford, Bradford, West Yorkshire, United Kingdom.,Department of Anatomy II, University of Erlangen-Nürnberg, Erlangen, Germany
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Ben Ner D, Sher I, Hamburg A, Mhajna MO, Chibel R, Derazne E, Sharvit-Ginon I, Pras E, Newman H, Levy J, Khateb S, Sharon D, Rotenstreich Y. Chromatic pupilloperimetry for objective diagnosis of Best vitelliform macular dystrophy. Clin Ophthalmol 2019; 13:465-475. [PMID: 30880907 PMCID: PMC6407903 DOI: 10.2147/opth.s191486] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the pupil response of Best vitelliform macular dystrophy (BVMD) patients for focal blue and red light stimuli presented at 76 test points in a 16.2° visual field (VF) using a chromatic pupilloperimeter. Methods An observational study was conducted in 16 participants: 7 BVMD patients with a heterozygous BEST1 mutation and 9 similar-aged controls. All participants were tested for best-corrected visual acuity, chromatic pupilloperimetry and Humphrey perimetry. Percentage of pupil contraction (PPC), maximal pupil contraction velocity (MCV) and latency of MCV (LMCV) were determined. Results The mean PPC and MCV recorded in BVMD patients in response to red stimuli were lower by >2 standard errors (SEs) from the mean of controls in 47% and 43% of VF test points, respectively. The mean PPC and MCV recorded in the patients in response to blue stimuli were lower by >2 SEs from the mean of controls in 36% and 24% of VF test points, respectively. The patients’ mean and median MCV recorded in response to red light correlated with their Humphrey mean deviation score (r=−0.714, P=0.071 and r=−0.821, P=0.023, respectively) and visual acuity (r=0.709, P=0.074 and r=0.655, P=0.111, respectively). A substantially shorter mean LMCV was recorded in BVMD patients compared to controls in 54% and 93% of VF test points in response to red and blue light, respectively. Receiver operating characteristic analysis for LMCV in response to red light identified a test point at the center of the VF with high diagnostic accuracy (area under the curve of 0.94). Conclusion Chromatic pupilloperimetry may potentially be used for objective noninvasive assessment of rod and cone cell function in different locations of the retina in BVMD patients.
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Affiliation(s)
- Daniel Ben Ner
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
| | - Ifat Sher
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel,
| | - Amit Hamburg
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
| | - Mohamad O Mhajna
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
| | - Ron Chibel
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
| | - Estela Derazne
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
| | - Inbal Sharvit-Ginon
- Department of Psychology, Bar Ilan University, Ramat Gan, Israel.,The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat Gan, Israel
| | - Eran Pras
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, .,The Matlow's Ophthalmo-Genetics Laboratory, Department of Ophthalmology, Assaf-Harofeh Medical Center, Zerifin, Israel
| | - Hadas Newman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel, .,Ophthalmology Department, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Jaime Levy
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ygal Rotenstreich
- Goldschleger Eye Institute, Sheba Medical Center, Tel Hashomer, Israel, .,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel,
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Scholl HPN, Kremers J, Besch D, Zrenner E, Jägle H. Progressive cone dystrophy with deutan genotype and phenotype. Graefes Arch Clin Exp Ophthalmol 2005; 244:183-91. [PMID: 16082559 DOI: 10.1007/s00417-005-0022-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Revised: 04/11/2005] [Accepted: 04/12/2005] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To study the electroretinographic signals originating in the long-wavelength-sensitive (L) and middle-wavelength-sensitive (M) cone pathways by means of large-field and multifocal cone type-specific electroretinograms (ERGs) in a patient with progressive cone dystrophy. METHODS A 65-year-old male patient with colour vision disturbances (age at onset 10 years), loss of visual acuity (14 years), and central visual field defects (40 years) was investigated. Large-field flicker-ERG responses to stimuli that exclusively modulated the L-cones or the M-cones, or the two simultaneously (both in-phase and in counter-phase), were measured. Short-wavelength-sensitive (S) cones were not modulated. Multifocal ERGs (mfERGs) were also recorded, with a pattern-reversing display that modulated only the L- or the M-cones at equal cone contrasts and average quantal catches. Genetic analysis of L- and M-pigment genes was performed on genomic DNA isolated from peripheral venous blood. RESULTS The patient showed a normal rod-driven ERG but reduced cone-driven electroretinographic amplitudes with normal implicit times in the International Society for Clinical Electrophysiology of Vision (ISCEV) standard ERG. The large-field flicker-ERG responses to pure L-cone modulation were significantly above noise level but were substantially reduced in comparison with both normal trichromatic subjects and (otherwise normal) deuteranopes. The L-cone driven electroretinographic implicit times and phases were within normal limits. The M-cone driven electroretinographic responses were not detectable. A model fit of all the L- and M-cone driven flicker-ERG data revealed that the responses were exclusively driven by the L-cones. Consistently, the cone type-specific mfERGs showed severely reduced but detectable responses to L-cone-isolating stimuli. The M-cone driven multifocal-ERG responses were undistinguishable from noise. The L- and M-pigment gene array consisted of only a single L-pigment gene. The complete coding sequence of this gene was determined and showed no abnormality. CONCLUSIONS This patient exhibits a coincidence of progressive cone dystrophy and deuteranopia. The molecular genetic data of the L/M-pigment gene array is consistent with the deutan phenotype. It cannot be excluded that the rearrangement of the X-chromosome pigment gene array is responsible for the cone dystrophy in this patient. It is, however, suggested that the dichromacy and the cone dystrophy have different and independent genetic origins.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Ophthalmology, University of Bonn, Ernst-Abbe-Strasse 2, 53127, Bonn, Germany.
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Rigaudière F, Roux C, Lachapelle P, Rosolen SG, Bitoun P, Gay-Duval A, Le Gargasson JF. ERGs in female carriers of incomplete congenital stationary night blindness (I-CSNB). A family report. Doc Ophthalmol 2004; 107:203-12. [PMID: 14661912 DOI: 10.1023/a:1026212318245] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
ERG findings in five sisters are reported. By pedigree analysis, four of the five must be obligate carriers for I-CSNB since their sons were affected (impaired night vision, reduced visual acuity, variable ametropia, congenital nystagmus and ERG with both scotopic and photopic b-wave reduced amplitude). The fifth was childless at the time of examination and her ERG analysis was normal. Three of the four obligate carriers showed significant reduction in the sum of the OPs amplitude as previously reported as being an electrophysiological signs in female carriers: two without alteration in other ERG components and the third with association with a flicker ERG amplitude significantly increased. The fourth female carrier showed a normal sum of the OPs amplitude whereas the other b-wave ERG or flicker amplitudes were significantly decreased. These last two ERG results suggest a possible modifications of synaptic transmission at a post-receptoral site (outer plexiform layer or involvement of the bipolar pathways) in these two carriers.
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Affiliation(s)
- Florence Rigaudière
- Université Paris 7, UFR Lariboisière-Saint-Louis, Unité INSERM U-483, Service de Biophysique, Département Vision, Paris, France.
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Abstract
To study the L- and M-cone pathways and their interactions in patients with cone and cone-rod dystrophies, ERG responses were measured to stimuli which modulated exclusively the L- or the M-cones, or the two simultaneously. The L- and M-cone driven ERG amplitudes were considerably reduced in the patients. The mean phases of the L-cone driven ERGs in the patients lagged those of normals significantly, whereas the mean M-cone driven ERGs were significantly phase advanced resulting in a substantial phase difference between the two ERG responses. These phase changes in the L- and M-cone driven responses in the patients cannot be detected with standard ERG techniques.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Pathophysiology of Vision and Neuroophthalmology, University Eye Hospital, 72076 Tübingen, Germany
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Kremers J. The assessment of L- and M-cone specific electroretinographical signals in the normal and abnormal human retina. Prog Retin Eye Res 2003; 22:579-605. [PMID: 12892643 DOI: 10.1016/s1350-9462(03)00049-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Electroretinography (ERG) is a non-invasive method that can contribute to a description of the functional organization of the human retina under normal and pathological circumstances. The physiological and pathophysiological processes leading to an ERG signal can be better understood when the cellular origins of the ERG are identified. The ERG signal recorded at the cornea is initiated by light absorption in the photoreceptors which leads to activity in the photoreceptors and in their post-receptoral pathways. Light absorption in distinct photoreceptor types may lead to different ERG responses caused either by differences between the photoreceptors or between their post-receptoral pathways. The description of contributions of the different photoreceptor types to the ERG may therefore give more detailed insight in the origins of the ERG. Such a description can be obtained by isolating the responses of a single photoreceptor type. Nowadays, careful control of differently colored light sources together with the relatively well-known cone and rod fundamentals enables a precise description and control of photoreceptor excitation. Theoretically, any desired combination of photoreceptor excitation modulation can be achieved, including conditions in which the activity in only one photoreceptor type is modulated (silent substitution). In this manner the response of one photoreceptor type is isolated without changing the state of adaptation. This stimulus technique has been used to study the contribution of signals originating in the different photoreceptor types to the human ERG. Furthermore, by stimulating two or more photoreceptor types simultaneously, the interaction between the different signals can be studied. With these new techniques results of measurements in healthy subjects and patients with retinal diseases can be compared. This approach should ultimately help to develop better diagnostic tools and result in a fuller description of the changes and the pathophysiological mechanisms in retinal disorder. Finally, data obtained with cone and rod specific stimuli may lead to a reinterpretation of the standard ERG used in a clinical setting.
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Affiliation(s)
- Jan Kremers
- Department of Experimental Ophthalmology, University of Tübingen Eye Hospital, Röntgenweg 11, D-72076 Tübingen, Germany.
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Scholl HPN, Kremers J. L- and M-cone driven large-field and multifocal electroretinograms in sector retinitis pigmentosa. Doc Ophthalmol 2003; 106:171-81. [PMID: 12678282 DOI: 10.1023/a:1022505204826] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The purpose was to study long- (L-) and middle-wavelength-sensitive (M-) cone-driven ERGs and multifocal ERGs (mfERGs) in sector retinitis pigmentosa (sector RP). Two eyes of two patients with sector RP were measured. ERG responses were measured to stimuli which modulated exclusively the L- or the M-cones or the two simultaneously (both in-phase and in counter-phase) with predefined cone contrast leaving the S-cones unmodulated. For comparison, mfERGs were recorded with the visual evoked response imaging system, using a resolution of 61 hexagonal elements within a 30-degree visual field. The two sector RP patients exhibited a general reduction of the L-/M-cone driven ERG sensitivity. Patient 1 exhibited a slight delay of the M-cone driven ERG. In patient 2, L-cone driven ERG was moderately delayed. In both patients, the phases of the L- and the M-cone driven ERGs were positively correlated with cone contrast. The data of the L/M-cone driven ERGs, the mfERGs and the standard photopic ERGs matched each other qualitatively. We conclude that the sector RP patients were clearly different from normal for both the L- and M-cone driven large-field and the multifocal ERGs. Previously, we investigated L- and M-cone driven ERGs in patients with generalized RP and found several features that differ from the sector RP patients. Our data are in agreement with our previous proposition that amplitudes and phases of the L- and M-cone driven ERGs can be differently affected by retinal disorders.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Experimental Ophthalmology, University Eye Hospital, Tübingen, Germany
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Scholl HPN, Schuster AM, Vonthein R, Zrenner E. Mapping of retinal function in Best macular dystrophy using multifocal electroretinography. Vision Res 2002; 42:1053-61. [PMID: 11934455 DOI: 10.1016/s0042-6989(02)00034-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In order to evaluate the function of the retina in Best macular dystrophy (BMD) 18 patients were examined by means of the multifocal electroretinogram (mfERG). The mfERG peak amplitudes of the central and pericentral responses were significantly reduced in the BMD patients (p<0.001). The ERG amplitude decrease of the central response was significantly correlated with visual acuity loss and with the funduscopic staging. The implicit times in more eccentric groups were slightly but significantly increased. The markedly reduced mfERG amplitudes with only slightly increased implicit times may indicate cone photoreceptor cell loss or damage to the cone outer segments.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Pathophysiology of Vision and Neuro-Ophthalmology, University Eye Hospital, Schleichstrasse 12-16, 72076 Tübingen, Germany.
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