A tricolor light source for stimulation and adaptation in electroretinography

Kooijman, Aart C.; Damhof, A

doi:10.1007/bf00157131

Cited by 7 publications

(5 citation statements)

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“…Platinum needles were placed subcutaneously at the temple and top of the head between the ears as reference and ground electrodes respectively. Stimuli were brief white flashes (4 ms) delivered from a light source within the Kooijman electrode (Kooijman & Damhof, 1986 ). The RETImap system (Roland Consult) was used for stimulus generation and data acquisition.…”

Section: Methodsmentioning

confidence: 99%

Early disruption of photoreceptor cell architecture and loss of vision in a humanized pig model of usher syndromes

et al. 2022

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Usher syndrome (USH) is the most common form of monogenic deaf-blindness. Loss of vision is untreatable and there are no suitable animal models for testing therapeutic strategies of the ocular constituent of USH, so far. By introducing a human mutation into the harmonin-encoding USH1C gene in pigs, we generated the first translational animal model for USH type 1 with characteristic hearing defect, vestibular dysfunction, and visual impairment. Changes in photoreceptor architecture, quantitative motion analysis, and electroretinography were characteristics of the reduced retinal virtue in USH1C pigs. Fibroblasts from USH1C pigs or USH1C patients showed significantly elongated primary cilia, confirming USH as a true and general ciliopathy. Primary cells also proved their capacity for assessing the therapeutic potential of CRISPR/Cas-mediated gene repair or gene therapy in vitro. AAV-based delivery of harmonin into the eye of USH1C pigs indicated therapeutic efficacy in vivo.

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Section: Methodsmentioning

confidence: 99%

Early disruption of photoreceptor cell architecture and loss of vision in a humanized pig model of usher syndromes

et al. 2022

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“…As stated by Reichel et al [3], photopically matched stimuli [9] cannot sufficiently separate all three cone systems. Computer-assisted spectral ERG with four different color stimuli [22] or a tricolor light source [23] was proposed for human ERG and applied in normal subjects [22,23] and vitrectomy candidates [22]. Computer-assisted spectral ERG with four different color stimuli [22] or a tricolor light source [23] was proposed for human ERG and applied in normal subjects [22,23] and vitrectomy candidates [22].…”

Section: Discussionmentioning

confidence: 99%

Color electroretinography

Kellner

Foerster

1992

Doc Ophthalmol

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Electroretinograms to white and color stimuli were recorded in four normal subjects and nine subjects with different cone dysfunctions, including protanopia, cone dystrophy, cone dystrophy with supernormal b-waves at dark adaptation, cone dystrophy with missing b-waves during light adaptation and rod-cone dystrophy with blue cone hypersensitivity. Color stimuli were obtained with Kodak Wratten filters in blue, blue-green, green, yellow and red. Electroretinograms to all stimuli were recorded during dark and light adaptation with different stimulus intensities and to 30-Hz flicker stimulation. In protanopia, responses to red during light adaptation and flicker stimulation were reduced. All cone dystrophies showed reduced amplitudes and prolonged implicit times to red when dark adapted. The light-adapted responses were equally reduced to all color stimuli in cone dystrophy and cone dystrophy with supernormal b-waves. Contrary to other cone dystrophies, in cone dystrophy with missing b-waves, responses to red were severely reduced and responses to green were preserved, indicating a predominantly red cone dysfunction. Blue cone hypersensitivity was clearly distinct from other dystrophies in having large response to blue and blue-green and much smaller responses to all other colors in all stimulus conditions. The electroretinogram with color stimuli allowed separation of different cone dysfunctions and identification of new retinal dysfunction syndromes.

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“…Animals were positioned in sternal recumbency, eyelids retracted using Barraquer eyelid retractors, and dorsally positioned stay sutures were placed in the bulbar conjunctiva to keep the pupils centered. Kooijman contact electrodes with a built in 4 W white LED stimulator served as both active electrodes and Ganzfeld stimulator 23–25 . To improve conduction, these were coupled to both corneas with a 0.2% carbomer gel (Clinitas Hydrate™, Altacor).…”

Section: Methodsmentioning

confidence: 99%

“…Kooijman contact electrodes with a built in 4 W white LED stimulator served as both active electrodes and Ganzfeld stimulator. [23][24][25] To improve conduction, these were coupled to both corneas with a 0.2% carbomer gel (Clinitas Hydrate™, Altacor). Subcutaneous needles served as reference and ground electrodes and were placed 4 cm from the lateral canthi of both eyes and at the occipital protuberance, respectively.…”

Section: Electroretinographymentioning

confidence: 99%