Erich E. Sutter's research while affiliated with Smith-Kettlewell Eye Research Institute and other places

Publications (64)

Article
Full-text available
Purpose To investigate the topographic changes of the dark-adapted multifocal electroretinogram (mfERG) across adulthood in the central retina and compare the topography between macular versus extramacular, nasal versus temporal, and inferior versus superior retinal areas. Methods Sixty-five subjects (18–88 years) received a comprehensive dilated...
Article
The multi-focal electroretinogram (mfERG) acquires spatially resolved retinal signals that can facilitate diagnosis and treatment of visual disorders. However, much information contained in the recorded signals remains unexploited. Here, we use the mfERG to detect age-related changes in retinal recovery from a photopic double-flash response. mfERGs...
Article
This study relates to local field potentials and single-unit responses in cat visual cortex elicited by contrast reversal of bar gratings that were presented in single, double, or multiple discrete patch (es) of the visual field. Concurrent stimulation of many patches by means of the pseudorandom, binary m-sequence technique revealed interactions b...
Article
To investigate the retinal responses generated by flash interactions in a recently introduced "global (full-screen) flash" stimulus paradigm to record the multifocal electroretinogram (mfERG). Five normal individuals were studied with stimulation combining multifocal (pseudorandom) flashes with interleaved global (periodic, full-screen) flashes. Th...
Article
To investigate the mechanism of bilateral central vision loss in a patient with graft-versus-host disease. Observational case report. A 43-year-old man with graft-versus-host disease developed acute painless progressive central vision loss, first in the left eye and then in the right. The patient underwent slit-lamp biomicroscopy, indirect ophthalm...
Article
Full-text available
To determine age-related changes in retinal response dynamics derived from multifocal electroretinograms (mfERGs). MfERG data were obtained from 70 subjects with normal phakic eyes, age 9 to 80 years. Whereas the first- and higher-order kernels resulting from the mfERG contain detailed information regarding the nonlinear response dynamics of the re...
Article
To evaluate macular function using multifocal electroretinography (mfERG) in a cohort of asymptomatic patients taking hydroxychloroquine and a patient with maculopathy secondary to hydroxychloroquine treatment. mfERG recordings were obtained for both eyes of 11 patients taking hydroxychloroquine without clinical signs of toxicity and 1 patient with...
Article
We tested a prototype stimulator interfaced with a commercially available scanning laser ophthalmoscope designed to measure retinal capillary perfusion (Heidelberg Retina Flowmeter (HRF)). The add-on stimulator optically superimposed the image of a monitor display on to the subject's retina coaxially with the imaging optics of the HRF. The purpose...
Article
Purpose: To determine and compare age-related changes in amplitude and latency of the impulse response function derived from the multifocal electroretinogram (mfERG) (IRFe) and from psychophysical experiments (IRFp). Methods: Single flash IRFe were derived from the binary kernel series of mfERG recordings in 70 normal subjects (ages 9 to 80 years)...
Article
The aim of the present investigation was to determine the nature and spatial distribution of selective visual attention. Using cortical source localization of ERP data corresponding to 60 task-irrelevant stimuli across the visual field, we assessed attention effects on visual processing. Consistent with previous findings, visual processing was enha...
Article
To objectively investigate and longitudinally monitor retinal function in patients with choroidal neovascularization (CNV) due to exudative age-related macular degeneration (AMD) and myopia using multifocal electroretinography (mfERG). Patients with classic and occult subfoveal CNV secondary either to AMD or to myopia were enrolled in the study. Th...
Article
The multifocal electroretinogram (mfERG) allows for functional field mapping by concurrently deriving responses from a large number of retinal locations. The stimulus resolution most commonly used consists of 103 hexagonal elements. Here, we stimulated with an array of 509 elements. To determine the extent to which the multifocal ERG shows anatomic...
Article
The cortical magnification factor characterizes the area of human primary visual cortex activated by a stimulus as a function of angular distance from an observer's line of sight. This study estimates human cortical magnification using an electrophysiological method with excellent temporal resolution: visual evoked potential (VEP) dipole source loc...
Article
To search for an optic nerve head component (ONHC) in the monkey's (Macaca mulatta) multifocal electroretinogram (mERG), mERGs from three animals were recorded with different electrode configurations. A component with a latency that varied with distance from the optic nerve head was easily identified by eye in recordings from the speculum of a Buri...
Article
To assess early functional retinal changes in diabetics without retinopathy, a new multifocal stimulus paradigm was used that emphasises fast adaptive response contributions. 25 normal control subjects (25 eyes) and 11 diabetics without retinopathy (22 eyes) served as subjects. Stimulation and analysis were performed with Veris Science 4.0. A stimu...
Article
Full-text available
This study addresses fundamental problems regarding the enhancement and isolation of ganglion cell-related response components of the multifocal ERG for the purpose of mapping glaucomatous dysfunction.
Conference Paper
This study examines ganglion cell dysfunction in glaucoma using a global flash multifocal ERG technique. The optic nerve head components and retinal components of patients were significantly affected, in different ways, compared to control eyes.
Article
The multifocal m-sequence technique is a versatile set of tools for visual electrophysiology designed to provide access to the complex dynamic interplay of converging signals in the central nervous system. Here, a number of uses for the technique are demonstrated, with examples from human electroretinography. A simple relationship between the binar...
Conference Paper
This study addresses fundamental problems regarding the enhancement and isolation of ganglion cellrelated response components of the multifocal ERG for the purpose of mapping glaucomatous dysfunction.
Article
This study examines the characteristics and the naso-temporal asymmetries of the higher-order oscillatory components of the multifocal electroretinogram (mERG). The magnitude of the mERG asymmetry and the mechanisms which produce it have not been studied previously. We recorded the mERG from seven normal observers using slow multifocal flicker and...
Article
The interpretation of binary kernels derived by means of the mulifocal ERG has frequently been the source of confusion and controversy. The aim of this paper is to provide an intuitive understanding of the concept of kernels and to demonstrate with models and examples, the relationship between the kernels and individual responses. The sample data u...
Article
The goal of this study was to acquire a detailed spatial and temporal map of primary visual cortex using a novel VEP stimulus and analysis technique. A multi-stimulus array spanning the central 18 degrees of the visual field was used where each of 60 checkerboard stimulus 'patches' was simultaneously modulated with an independent binary m-sequence...
Article
To investigate the topography of cone electroretinographic (ERG) responses in the enhanced S cone syndrome (ESCS). A 19-year-old female with ESCS who was one of the original cases defining the syndrome was studied. Full-field, focal (Maculoscope) and multifocal (VERIS) ERGs were performed using white light. Multifocal ERG responses were also genera...
Article
Small areas of retinal pathology may pose diagnostic difficulties. The noninvasive multifocal electroretinogram (MF-ERG) provides a topographical mapping of retinal function. Its role in the diagnosis of macular diseases is examined in age-related macular degeneration (AMD). AMD is a main cause of central visual loss in the elderly population, affe...
Article
Purpose: Small areas of retinal pathology may pose diagnostic difficulties. The noninvasive multifocal electroretinogram (MF-ERG) provides a topographical mapping of retinal function. Its role in the diagnosis of macular diseases is examined in age-related macular degeneration (AMD). AMD is a main cause of central visual loss in the elderly populat...
Article
The local responses of the multifocal ERG reveal continuous changes in the second order waveforms from the nasal to the temporal retina. Scrutiny of these changes suggests the presence of an additive component whose latency increases with the distance of the stimulus from the optic nerve head. This observation led to the hypothesis of a contributin...
Conference Paper
Multifocal electroretinograms (M-ERGs) recorded with the conventional flicker protocol originate predominantly from the distal retinal layers, that is, from receptors, bipolar cells and Mueller cells.
Article
The role of multifocal electroretinography (MF-ERG) in the diagnosis and follow-up of localized areas of retinal dysfunction is discussed. A 42-year-old male with the preliminary diagnosis of optic neuritis in his left eye was referred for evaluation with the MF-ERG. Simultaneous cone ERGs were obtained from 103 locations within the central 50 degr...
Article
To gain new insight into the effects of monocular deprivation, we studied the visual cortex of adult cats deprived of vision in one eye. Local field potentials were recorded in response to contrast reversal of square-wave gratings modulated in time either by pseudorandom, m-sequences or periodically. We have found that: (1) stimulation of the retin...
Article
To assess local retinal function in patients with retinitis pigmentosa (RP), multi-focal ERGs and local thresholds (static visual fields) were obtained on eight RP patients with visual acuities of or better. All eight patients showed multi-focal responses with normal timing within the central 5 deg. However, there were few responses with normal tim...
Article
Full-text available
To investigate focal abnormalities in the electroretinogram (ERG) signal in diabetic patients, with and without retinopathy, using a multifocal ERG. Sixteen patients with diabetes mellitus, 8 of whom had diabetic retinopathy (mean duration of diabetes: 18.5 years) and 19 approximately age-matched healthy volunteers underwent multifocal ERG testing....
Article
Full-text available
To study components related to parallel processing of information across the visual field, multi-focal pattern reversal visual evoked potentials (VEPs) were recorded using binary m-sequences. Contrast, chromatic, spatial and temporal characteristics of the stimuli were varied in order to favor contributions from either M or P pathways. Responses we...
Chapter
Specific combination of first and second order multifocal ERG components provides a signal-to-noise improvement in extracted ganglion cell contributions equal to doubling the recording time.
Article
Conventional electroretinographic techniques do not permit efficient mapping of retinal responsiveness for the detection of small dysfunctional areas. This study explores the application of a new technique that makes such mapping possible. It utilizes a multifocal electroretinogram technique based on binary m sequences that simultaneously tests a l...
Article
Purpose. The implicit times of cone ERGs are delayed even during the early stages of retinitis pigmentosa (RP)1 due to changes at both receptoral and post-receptoral sites2. To assess the extent to which these delays reflect local versus global retinal changes, the timing of multi-focal, cone ERGs was examined. Methods. Multi-focal, cone ERGs were...
Article
Purpose. A component of the multi-focal ERG generated at the optic nerve head by ganglion cell fibers is abnormal in optic atrophy and pigmentary glaucoma (Bearse, et al., ARVO 1995). To explore the sensitivity of the multi-focal ERG, we measured the retinal distributions of this component and the first and second order responses in primary open an...
Article
Purpose. To gain further insight into the changes of retinal function in diabetes, we explored the second order component of the multi-focal ERG under different stimulus conditions in early non-proliferative diabetic retinopathy (NPDR), diabetes without retinopathy and healthy volunteers. Methods. The visual stimulus consisted of 103 hexagons indep...
Article
The purpose of this study was to evaluate the use of slow multifocal m-sequence stimulation in analyzing the topographic distribution and underlying mechanisms (including nonlinearities) of the retinal oscillatory potentials (OPs). In giving us access to the response topography and the nonlinear characteristics of the OPs, the m-sequence technique...
Article
Field potentials were recorded from cat striate cortex, either between an epidural screw electrode and a cannula-electrode inserted deep in the gray matter (transcortical recording) or with a pair of metal microelectrodes. Electrodes were placed bilaterally near the cortical projection of the area centralis. The horizontal separation of the recordi...
Article
Full-text available
Two types of field potentials were identified in cat visual cortex using contrast reversal of oriented bar gratings: a short-latency fast-local component with a retinotopic organization similar to that seen with single-unit discharges at the same cortical site, and a slow, nonretinotopic component with a longer peak latency. The slow-distributed co...
Article
Full-text available
Visual evoked potentials (VEPs) to luminance and pattern reversal stimulation were derived for a large number of small areas throughout the central visual field. In one study, the field was tested with a stimulus array consisting of 64 equal-area patches. Local response components were extracted by independent m-sequence modulation of the patches....
Article
A technique of multi-input systems analysis is used to explore the field topography of ERG responses to local luminance modulation. Variations in amplitude and wave form are studied within the central 23 degrees. Outside the fovea, the amplitude appears to follow a simple power law rx as a function of eccentricity r where x is approximately -2/3. T...
Article
This paper discusses an experimental communication system for severely disabled persons that utilizes electrical responses from the brain. Scientific background and methodology as well as the results of a preliminary evaluation are presented.
Article
An algorithm is presented for the fast computation of the m-transform, a Hadamard transform intimately related to cross-correlation of analog signals with binary m-sequences. It is shown that m-transforms are in the same Hadamard equivalence class as Walsh–Hadamard transforms and can, thus, becomputed by means of the Fast Walsh Transform (FWT) algo...
Article
We directly compared nonlinear kernels of normal human pattern electroretinograms (PERGs) and corresponding localized flash ERGs (FERGs). The FERG was triphasic and resembled an adaptive process because it decayed slowly without changing shape over several kernel orders and interpulse intervals. The PERG was biphasic in the slice nearest the diagon...
Article
Two different mechanisms are presumed to contribute to pattern electroretinograms: non linearities of the local luminance response and nonlinear effects of lateral interactions. Previous attempts to discriminate the two components relied on the theoretical MTF of the optics. In this study, techniques of nonlinear systems analysis are used to extrac...
Article
Visual sensitivity to stereoscopic disparity changes was measured both psychophysically and by means of evoked potentials. The binocular disparity of a dynamic random-dot stereogram portraying a single flat plane alternated between two values symmetrical about the plane of fixation. The threshold for disparity alternation of the stereoscopic plane...
Article
Perception of tilt in depth on the basis of spatial frequency difference between the two eyes was subjected to new tests to determine whether it could be explained by conventional binocular disparity mechanisms. When usual disparity cues are invalidated by rapidly changing displays and by using stimuli uncorrelated between the two eyes, perception...

Citations

... Of the nonlinear contributions to the mfERG, the optic nerve head component (ONHC) which has been attributed to the nerve fiber layer [20][21][22][23] is reflected in a large naso-temporal asymmetry of the mfERG response that may be diminished in glaucoma [22,24]. Indeed, the IC has been shown to contain a large naso-temporal asymmetry, while this is only slightly present in the focal flash response [15,16,19]. ...
... Our patients' recordings were compared to an age matched control group as age has been discussed as an influence on the MF-ERG [17,18], even though, comparing subjects aged 20-40 with those 41-60, we have previously not been able to detect a significant influence of age on the first order response of the multifocal ERG [19]. It has recently been suggested that the differences due to age reported previously might be due to an increase in lens density due to cataract occurring in the elderly (ARVO 2001, Sig meeting and [20]). ...
... The multifocal ERG (MF-ERG) is a relatively new method that allows mapping of retinal function through simultaneous testing of multiple retinal areas in a very short time. Its applicability has recently been demonstrated in patients with other macular disorders [9][10][11][12][13][14]. ...
... 2,3 Recently, the mfERG and mfVEP have been used widely in the investigation of pathological changes or functional variations in the visual system. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] These findings suggested that the mfERG and mfVEP are effective and powerful techniques to explore the changes in the visual system due to pathological conditions. ...
... For example, with an increase in the stimulus base interval, a small induced response component resulting from the response to the following stimulus in the m-sequence cycle becomes apparent. At a stimulus base interval of ~54 ms there is no overlap between this induced component and the m sequence response [10]. Under these conditions, oscillatory potentials become apparent in the induced component [11] and the sensitivity to detect NTG increases to about 85% [12]. ...
... At a stimulus base interval of ~54 ms there is no overlap between this induced component and the m sequence response [10]. Under these conditions, oscillatory potentials become apparent in the induced component [11] and the sensitivity to detect NTG increases to about 85% [12]. In the monkey, OPs elicited by such a stimulus are increasingly affected with glaucomatous damage [13]. ...
... With a mfERG using long m-stimulus steps of 100-ms duration, glaucoma patients differed significantly from controls, predominantly in the central 20°when the latencies of the mfERG N2-on response were analysed [18]. Global flashes introduced into the stimulus sequence increased the mfERG's sensitivity to detect retinal dysfunction in glaucoma [19][20][21][22]. The mfERG response obtained with the global flash paradigm contains a direct component (DC) as a response to the focal flash of the m-sequence step and induced components (ICs) as a response, induced by the influence of the preceding focal flash on the response to the following global flashes within the m-sequence step. ...
... In the primate, the naso-temporal asymmetry thought to be caused by this component is diminished following intravitreal administration of Tetrodotoxin, which blocks amacrine and ganglion cells [16]. The ONHC appears to be diminished in glaucoma [15, 17]. Bearse et al. have shown that the ONHC asymptotes in amplitude at a contrast of about 60% whereas the retinal component (RC) shows a linear relationship with contrast [18]. ...
... In order to determine if the histological observation of EODF-mediated neuroprotection in EAAC1 −/− mice reflects functional aspects, we examined visual function using mfERG. We analyzed the second-order kernel (2 K) component, which appears to be a sensitive indicator of inner retinal dysfunction 5-10,21,23,24 and is impaired in glaucoma patients 26 . The response topography demonstrating the 2 K component revealed that the average visual responses were OCT, mfERG and IOP of mice were measured before sampling at 12 W. β-HB levels in the blood of mice were measured every 24 h in the first week of the experiment. ...
... As this IC contains effects of the focal flash responses on subsequent responses elicited in the same, as well as in surrounding areas, it is believed to reflect properties of ganglion cell receptive fields. It has since been shown that mfERG abnormalities in glaucoma are due to loss of this optic nerve head component (ONHC) [4]. The existence of the ONHC has been well established in humans and in animal models [18]. ...