Retinal receptive fields under different adaptation levels studied with pattern-evoked ERG

Korth, Matthias; Ilschner, Susanne; Sembritzki, O.

doi:10.1007/bf02155807

Cited by 5 publications

(7 citation statements)

References 30 publications

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“…3B). It also agrees with previous measurements on the luminosity function of the PERG onset response based on the measurement of the amplitude from the first positive wave to the following negative trough during exposure to 3 scotopic Td [15]. From this we concluded that the PERG, depending on the radiation intensity chosen, reflects both the scotopic and photopic sensitivity function.…”

Section: Resultssupporting

confidence: 80%

“…According to the present investigation, the pattern-specific response of the PERG displays spatial tuning under not only photopic but also scotopic conditions. In a related study, Korth et al [15] found a low-spatial frequency fall-off in the PERG under scotopic conditions in two of three subjects that still cannot be explained by single-cell studies [30]. The present results corroborate the observation of Korth et al at still lower radiation intensities, well below the psychophysical cone threshold.…”

Section: Discussionsupporting

confidence: 82%

“…Another finding of general interest in the present investigation is the waveforrn of the PERG onset-response, which is essentially the same as that of the off-effect in the LERG. Previously the PERG offset-response evoked by a stripe pattern has been interpreted mainly as being produced by a local increase in luminance generated in more distal parts of the retina [15]. According to the present study, this applies also to checkerboard stimulation and to the scotopic PERG evoked by onset-offset stimulation.…”

Section: Discussionmentioning

confidence: 64%

“…This so-called pattern electroretinogram (PERG) aroused special interest because it was found gradually to disappear after degeneration of retinal ganglion cells resulting from traumatic injury or surgical section of the optic nerve in humans [2,3], cats [4,5] and monkeys [6], whereas the luminance ERG (LERG) remained unchanged (deviant findings [7] are discussed elsewhere [8]). Therefore, most investigators believe that the LERG represents the electrical activity of the photoreceptor and inner nuclear layer, whereas the innermost retinal layers, including the ganglion cell layer, generate the PERG [9-111. As numerous investigations have shown that the PERG reflects the activity driven by cones [12,13], relative few data have been gathered under low intensity levels of stimulation, and none under strictly scotopic conditions [14,15]. The present study presents evidence that a PERG can be recorded under strictly scotopic conditions, i.e., even below the psychophysical light threshold of cones.…”

Section: Introductionmentioning

confidence: 57%

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Scotopic versus photopic pattern onset-offset electroretinograms

1992

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We investigated the contribution of rods and cones to the human pattern electroretinogram to onset and offset checkerboards of different spatial frequency and wavelength in a 39 degrees x 39 degrees field. Under strictly scotopic conditions, there was a negative potential at onset and a positive potential at offset, whereas under photopic conditions, there was a positive potential at onset and a negative/positive potential at offset. Thus, the waveform to pattern onset (offset) was that of the luminance electroretinogram to decreasing (increasing) luminances. For pattern onset, the sensitivity difference 486-601 nm under scotopic and photopic conditions closely followed the luminosity function of rods and cones. The amplitude of the scotopic onset response increased with check size up to 3 degrees 30' and that of the photopic onset response, up to 30'. With larger checks, the scotopic and photopic onset response markedly decreased. This indicates antagonistic center-surround organization of the receptive fields under both scotopic and photopic conditions. By contrast, the offset response monotonically increased with check size under scotopic and photopic conditions, which suggests a luminance component in the pattern electroretinogram. Consequently, the pattern electroretinogram to reversing checkerboards has to be regarded as a mixture of both pattern- (contrast) and luminance-specific components.

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Section: Resultssupporting

confidence: 80%

Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 57%

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Scotopic versus photopic pattern onset-offset electroretinograms

1992

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“…Psychophysical evidence for reduced inhibitory surround size following dark adaptation in human observers may also be inferred from pattern-evoked electroretinograms undertaken in light-and dark-adapted conditions. 48 However, no such changes in basic receptive field characteristics have been reported in V1 of the monkey visual cortex. 49 Additionally, contrast sensitivity (area under the log contrast sensitivity function and peak log contrast sensitivity) is lower in older (compared with younger) adults under mesopic versus photopic adaptation conditions, 50 which may also contribute to the enlargement in RA in mesopic conditions.…”

Section: Discussionmentioning

confidence: 98%

Investigating the linkage between mesopic spatial summation and variations in retinal ganglion cell density across the central visual field

Hunter

Anderson

Redmond

et al. 2023

Ophthalmic Physiologic Optic

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PurposeThe relationship between perimetric stimulus area and Ricco's area (RA) determines measured thresholds and the sensitivity of perimetry to retinal disease. The nature of this relationship, in addition to effect of retinal ganglion cell (RGC) number on this, is currently unknown for the adaptation conditions of mesopic microperimetry. In this study, achromatic mesopic spatial summation was measured across the central visual field to estimate RA with the number of RGCs underlying RA also being established.MethodsAchromatic luminance thresholds were measured for six incremental spot stimuli (0.009–2.07 deg2) and 190.4 ms duration, at four locations, each at 2.5°, 5° and 10° eccentricity in five healthy observers (mean age 61.4 years) under mesopic conditions (background 1.58 cd/m2). RA was estimated using two‐phase regression analysis with the number of RGCs underlying RA being calculated using normative histological RGC counts.ResultsRicco's area exhibited a small but statistically insignificant increase between 2.5° and 10° eccentricity. Compared with photopic conditions, RA was larger, with the difference between RA and the Goldmann III stimulus (0.43°) being minimised. RGC number underlying RA was also higher than reported for photopic conditions (median 70 cells, IQR 36–93), with no significant difference being observed across test locations.ConclusionsRicco's area and the number of RGCs underlying RA do not vary significantly across the central visual field in mesopic conditions. However, RA is larger and more similar to the standard perimetric Goldmann III stimulus under mesopic compared with photopic adaptation conditions. Further work is required to determine if compensatory enlargements in RA occur in age‐related macular degeneration, to establish the optimal stimulus parameters for AMD‐specific microperimetry.

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Ambient lighting alters pattern electroretinogram P50 peak time and spatial sensitivity

Tucker,

Marmoy,

Handley

et al. 2024

Doc Ophthalmol

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Purpose Our aim was to explore the effect of ambient lighting on the pattern ERG (PERG). Methods We compared PERGs recorded in two conditions; room lights on and room lights off. PERGs from 21 adult participants were recorded from each eye to high contrast checks of 50’ side width, reversing 3rps in a large (30°) and then standard (15°) field. This was performed first in lights-ON conditions, then 2 min after the room lights were switched off. A minimum of 2 averages of 300 trials were acquired for each condition. A subset of 10 participants had PERGs recorded to a 50’ check width with a range of stimulus contrasts (96–18%), also to a range of different check widths (100’–12’) at high contrast in both ambient lighting conditions in a 30° field. Results The lights-ON P50 median peak time (PT) was 3 ms earlier than the lights-OFF P50 from the 30° field (range 0–5 ms) and 15° field (range 0–6 ms). The earlier lights-ON P50 PT was evident at different stimulus contrasts, even after accounting for stimulus contrast reductions associated with stray ambient lighting in lights-ON conditions. Lights-OFF and lights-ON P50 PT were similar to different check widths; the lights-OFF P50 PT to a 50’ check width matched the lights-ON P50 PT to a 25’ check width. Conclusion PERG P50 PT in lights-ON ambient light conditions can be earlier than in lights-OFF ambient light conditions. The difference in P50 PT with ambient light may reflect alterations in spatial sensitivity associated with retinal adaptation. These results emphasise the clinical importance of consistent ambient lighting for PERG recording and calibration.

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Retinal receptive fields under different adaptation levels studied with pattern-evoked ERG

Cited by 5 publications

References 30 publications

Scotopic versus photopic pattern onset-offset electroretinograms

Scotopic versus photopic pattern onset-offset electroretinograms

Investigating the linkage between mesopic spatial summation and variations in retinal ganglion cell density across the central visual field

Ambient lighting alters pattern electroretinogram P50 peak time and spatial sensitivity

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