Noninvasive recording and response characteristics of the rat dc-electroretinogram

2002 ◽  
Vol 19 (6) ◽  
pp. 693-701 ◽  
Author(s):  
NEAL S. PEACHEY ◽  
J. BRETT STANTON ◽  
ALAN D. MARMORSTEIN
Keyword(s):  
Light Exposure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Experimental Manipulation ◽  
Sprague Dawley ◽  
Active Electrode ◽  
Slow Potential ◽  
Full Field ◽  
Stimulus Response ◽  
Response Characteristics

In response to light, the retinal pigment epithelium (RPE) generates a series of potentials that can be recorded using the dc-electroretinogram (dc-ERG). As these potentials can be related to specific cellular events, they provide information about RPE function and how that may be altered by disease or experimental manipulation. The purposes of the present study were to define a noninvasive means for recording the rat dc-ERG, to use this to define the stimulus–response properties of the major components, and to relate these results to measures of the rat electrooculogram (EOG). Parallel studies were conducted in two strains of rats (Long-Evans, LE; Sprague-Dawley, SD) that are commonly used in vision research. Rats were sedated with ketamine/xylazine and placed on a heating pad. Ag/AgCl wire electrodes were bridged with capillary tubes filled with Hanks balanced salt solution. The active electrode was placed in contact with the corneal surface and referenced to a second electrode placed within the orbit. The dc-ERG signal was amplified (dc-100 Hz), digitized, and stored offline. The duration of full-field flash stimuli was controlled using a mechanical shutter and flash luminance was controlled with neutral density filters. EOGs were recorded using subdermal platinum needle electrodes placed near the eye. In response to a 5-min light exposure, the dc-ERG of LE and SD rats included a distinct b-wave, after potential, c-wave, fast oscillation, and a slow potential of positive polarity the characteristics of which are consistent with a light peak.

scholarly journals Light-Evoked Responses of the Mouse Retinal Pigment Epithelium

2004 ◽  
Vol 91 (3) ◽  
pp. 1134-1142 ◽  
Author(s):  
Jiang Wu ◽  
Neal S. Peachey ◽  
Alan D. Marmorstein
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Inbred Strains ◽  
Experimental Manipulation ◽  
Mutant Mice ◽  
Rod Photoreceptor ◽  
Evoked Responses ◽  
Stimulus Response ◽  
Mouse Mutants

In response to light, the retinal pigment epithelium (RPE) generates a series of slow potentials that can be recorded as the c-wave, fast oscillation (FO), and light peak (LP) of the electroretinogram (ERG). As these potentials can be related to specific cellular events, they provide information about RPE function and how that may be altered by disease or experimental manipulation. In the present study we describe a noninvasive means for recording the light-evoked responses of the mouse RPE and use this to define the stimulus-response properties of the major components in three inbred strains of mice (BALBc/ByJ, C57BL/6J, and 129/SvJ) and two mouse mutants that reduce activity in the rod pathway. All of the major ERG components generated by the RPE are readily measured in the mouse. In albino strains (BALBc/ByJ and 129/SvJ) the intensity-response functions for the c-wave, FO, and LP are shifted toward lower intensities in comparison to those for C57BL/6J mice. Each of these components was markedly reduced in mice lacking transducin in which rod phototransduction is interrupted, indicating that they reflect primarily rod photoreceptor activity. All components were observed in no b-wave ( nob) mutant mice, indicating that inner retinal activity does not make a major contribution to these potentials. Further studies of mutant mice will allow us to define the functional consequences of gene manipulation on RPE function and to evaluate specific hypotheses regarding the generation of ERG components.

scholarly journals USH2A-Related Retinitis Pigmentosa: Staging of Disease Severity and Morpho-Functional Studies

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Benedetto Falsini ◽  
Giorgio Placidi ◽  
Elisa De Siena ◽  
Maria Cristina Savastano ◽  
Angelo Maria Minnella ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Collaborative Study ◽  
Staging System ◽  
International Standards ◽  
Full Field ◽  
Functional Studies ◽  
Cumulative Score

Usher syndrome type 2A (USH2A) is a genetic disease characterized by bilateral neuro-sensory hypoacusia and retinitis pigmentosa (RP). While several methods, including electroretinogram (ERG), describe retinal function in USH2A patients, structural alterations can be assessed by optical coherence tomography (OCT). According to a recent collaborative study, RP can be staged considering visual acuity, visual field area and ellipsoid zone (EZ) width. The aim of this study was to retrospectively determine RP stage in a cohort of patients with USH2A gene variants and to correlate the results with age, as well as additional functional and morphological parameters. In 26 patients with established USH2A genotype, RP was staged according to recent international standards. The cumulative staging score was correlated with patients’ age, amplitude of full-field and focal flicker ERGs, and the OCT-measured area of sub-Retinal Pigment Epithelium (RPE) illumination (SRI). RP cumulative score (CS) was positively correlated (r = 0.6) with age. CS was also negatively correlated (rho = −0.7) with log10 ERG amplitudes and positively correlated (r = 0.5) with SRI. In USH2A patients, RP severity score is correlated with age and additional morpho-functional parameters not included in the international staging system and can reliably predict their abnormality at different stages of disease.

Diffuse Pigmented Lesions in the Outer Retina: An Unusual Fundus Appearance

2019 ◽  
Vol 4 (3) ◽  
pp. 243-247
Author(s):  
Matthew D. Benson ◽  
Uriel Rubin ◽  
Marvi Cheema ◽  
Ian M. MacDonald ◽  
Matthew T.S. Tennant ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Full Field ◽  
Panel Testing ◽  
Pigmented Lesions ◽  
Hereditary Retinal Dystrophy ◽  
Ultrasound Findings ◽  
Chest X Ray

Purpose: This report describes and provides a differential diagnosis for a patient with unusual bilateral retinal pigmented lesions. Methods: A 40-year-old woman was found to have multiple flat, gray lesions scattered across her fundi, becoming larger and more confluent toward the periphery. There were small drusenlike deposits in her foveae. The hyperpigmented lesions demonstrated hypoautofluorescence with thickening of the retinal pigment epithelium and disruption of the overlying layers on optical coherence tomography (OCT). Full-field electroretinography revealed generalized reduced a- and b-wave amplitudes. Results: Chest x-ray, breast ultrasound, mammography, and pelvic ultrasound findings were negative for malignant etiologic factors. Panel testing results for hereditary retinal dystrophy were negative. Conclusions: Although the clinical and OCT appearance of the lesions is similar to congenital grouped pigmentation, the symmetric and bilateral nature of ocular findings coupled with electroretinographic changes suggest a possible retinal dystrophy. This case adds to the phenotypic diversity of pigmented fundus lesions.

scholarly journals Beyond AREDS Formulations, What Is Next for Intermediate Age-Related Macular Degeneration (iAMD) Treatment? Potential Benefits of Antioxidant and Anti-inflammatory Apocarotenoids as Neuroprotectors

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Serge Camelo ◽  
Mathilde Latil ◽  
Stanislas Veillet ◽  
Pierre J. Dilda ◽  
René Lafont
Keyword(s):  
Macular Degeneration ◽  
Light Exposure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Developed Countries ◽  
Age Related Macular Degeneration ◽  
Crocus Sativus ◽  
Subretinal Space ◽  
Major Health Problem ◽  
Age Related

Age-related macular degeneration (AMD) is the commonest cause of severe visual loss and blindness in developed countries among individuals aged 60 and older. AMD slowly progresses from early AMD to intermediate AMD (iAMD) and ultimately late-stage AMD. Late AMD encompasses either neovascular AMD (nAMD) or geographic atrophy (GA). nAMD is defined by choroidal neovascularization (CNV) and hemorrhage in the subretinal space at the level of the macula. This induces a rapid visual impairment caused by the death of photoreceptor cells. Intravitreal injection of anti-vascular endothelial growth factor (VEGF) antibodies is the standard treatment of nAMD but adds to the burden of patient care. GA is characterized by slowly expanding photoreceptor, and retinal pigment epithelium (RPE) degeneration patches progressively leading to blindness. There is currently no therapy to cure GA. Late AMD continues to be an unmet medical need representing a major health problem with millions of patients worldwide. Oxidative stress and inflammation are recognized as some of the main risk factors to developing late AMD. The antioxidant formulation AREDS (Age-Related Eye Disease Studies), contains β-carotene, which has been replaced by lutein and zeaxanthin in AREDS2, are given to patients with iAMD but have a limited effect on the incidence of nAMD and GA. Thus, to avoid or slowdown the development of late stages of AMD (nAMD or GA), new therapies targeting iAMD are needed such as crocetin obtained through hydrolysis of crocin, an important component of saffron (Crocus sativus L.), and norbixin derived from bixin extracted from Bixa orellana seeds. We have shown that these apocarotenoids preserved more effectively RPE cells against apoptosis following blue light exposure in the presence of A2E than lutein and zeaxanthin. In this review, we will discuss the potential use of apocarotenoids to slowdown the progression of iAMD, to reduce the incidence of both forms of late AMD.

A PRPH2 gene variant detected in retinitis punctata albescens with congenital hypertrophy of the retinal pigment epithelium

2020 ◽  
pp. 112067212096202
Author(s):  
Aowang Qiu ◽  
Yan Yu ◽  
Junlong Huang ◽  
Qinghuai Liu ◽  
Yannis M Paulus ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cone Photoreceptor ◽  
Blurred Vision ◽  
Full Field ◽  
Photoreceptor Outer Segments ◽  
Pigmented Lesions ◽  
Retinitis Punctata Albescens ◽  
Congenital Hypertrophy

Retinitis punctata albescens (RPA) is generally diagnosed by the presence of numerous clusters of white punctate lesions in the retina that progress over time and are related to several gene variants. The multifocal variant of congenital hypertrophy of the retinal pigment epithelium (CHRPE) is characterized by multiple, grouped, sharply circumscribed, pigmented spots. The PRPH2 gene encodes a photoreceptor-specific glycoprotein, which is essential for the morphogenesis of rod and cone photoreceptor outer segments. A 39-year-old Chinese female with nyctalopia, complained about blurred vision, presented a unique co-existing feature of RPA and CHRPE. Dilated fundus exam demonstrated numerous porcelain white discrete dots in both eyes and multiple, small, flat clusters of round brown to black pigmented lesions in the left eye. The full field electroretinography (ERG) showed decreased responses after standard dark adaptation and normal b-wave amplitudes after a long (4-h) dark-adapted period. A heterozygous PRPH2 splicing variant was detected in the proband. In addition, the same variant was found in her mother, her son, and her daughter. We describe a PRPH2 variant in a rare case of RPA associated with multifocal CHRPE of the same individual.

scholarly journals A convenient protocol for establishing a human cell culture model of the outer retina.

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1107 ◽  
Author(s):  
Savannah A. Lynn ◽  
Eloise Keeling ◽  
Jennifer M. Dewing ◽  
David A. Johnston ◽  
Anton Page ◽  
...  
Keyword(s):  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Experimental Manipulation ◽  
Age Related Macular Degeneration ◽  
Attractive Alternative ◽  
Outer Retina ◽  
Rpe Cells ◽  
Age Related ◽  
Culture Model

The retinal pigment epithelium (RPE) plays a key role in the pathogenesis of several blinding retinopathies. Alterations to RPE structure and function are reported in Age-related Macular Degeneration, Stargardt and Best disease as well as pattern dystrophies. However, the precise role of RPE cells in disease aetiology remains incompletely understood. Many studies into RPE pathobiology have utilised animal models, which only recapitulate limited disease features. Some studies are also difficult to carry out in animals as the ocular space remains largely inaccessible to powerful microscopes. In contrast, in-vitro models provide an attractive alternative to investigating pathogenic RPE changes associated with age and disease. In this article we describe the step-by-step approach required to establish an experimentally versatile in-vitro culture model of the outer retina incorporating the RPE monolayer and supportive Bruch’s membrane (BrM). We show that confluent monolayers of the spontaneously arisen human ARPE-19 cell-line cultured under optimal conditions reproduce key features of native RPE. These models can be used to study dynamic, intracellular and extracellular pathogenic changes using the latest developments in microscopy and imaging technology. We also discuss how RPE cells from human foetal and stem-cell derived sources can be incorporated alongside sophisticated BrM substitutes to replicate the aged/diseased outer retina in a dish. The work presented here will enable users to rapidly establish a realistic in-vitro model of the outer retina that is amenable to a high degree of experimental manipulation which will also serve as an attractive alternative to using animals. This in-vitro model therefore has the benefit of achieving the 3Rs objective of reducing and replacing the use of animals in research. As well as recapitulating salient structural and physiological features of native RPE, other advantages of this model include its simplicity, rapid set-up time and unlimited scope for detailed single-cell resolution and matrix studies.

scholarly journals Curcumin regulates intracellular calcium release and inhibits oxidative stress parameters, VEGF, and caspase-3/-9 levels in human retinal pigment epithelium cells

2017 ◽  
Vol 104 (4) ◽  
pp. 301-315 ◽  
Author(s):  
H Bardak ◽  
AC Uğuz ◽  
Y Bardak
Keyword(s):  
Oxidative Stress ◽  
Retinal Pigment Epithelium ◽  
Intracellular Calcium ◽  
Blue Light ◽  
Caspase 3 ◽  
Calcium Release ◽  
Light Exposure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Expression Levels

In this study, we aimed to observe whether curcumin (cur), a polyphenolic compound derived from the dietary spice turmeric, a yellow substance obtained from the root of the plant Curcuma longa Linn, has any protective effect against blue light irradiation in human retinal pigment epithelium (ARPE-19) cells. For this purpose, we evaluated the intracellular calcium release mechanism, poly ADP ribose polymerase (PARP), procaspase-3/-9 protein expression levels, caspase activation, and reactive oxygen species levels. ARPE-19 cells were divided into four main groups, such as control, cur, blue light, and cur + blue light. Results were evaluated by Kruskal–Wallis and Mann–Whitney U tests as post hoc tests. The cells in cur and cur + blue light samples were incubated with 20 μM cur. Blue light exposure was performed for 24 h in an incubator. Lipid peroxidation and cytosolic-free Ca2+ [Ca2+]i concentrations were higher in the blue light exposure samples than in the control samples; however, their levels were determined as significantly lower in the cur and cur + blue light exposure samples than in the blue light samples alone. PARP and procaspase-3 levels were significantly higher in blue light samples. Cur administration significantly decreased PARP and procaspase-3 expression levels. Reduced glutathione and glutathione peroxidase values were lower in the blue light exposure samples, although they were higher in the cur and cur + blue light exposure samples. Caspase-3 and -9 activities were lower in the cur samples than in the blue light samples. Moreover, vascular endothelial growth factor (VEGF) levels were significantly higher in the blue light exposure samples. In conclusion, cur strongly induced regulatory effects on oxidative stress, intracellular Ca2+ levels, VEGF levels, PARP expression levels, and caspase-3 and -9 values in an experimental oxidative stress model in ARPE-19 cells.

scholarly journals Suppression of Light-Induced Retinal Degeneration by Quercetin via the AP-1 Pathway in Rats

Antioxidants ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 79 ◽  
Author(s):  
Yasurou Koyama ◽  
Sachiko Kaidzu ◽  
Yong-Chul Kim ◽  
Yotaro Matsuoka ◽  
Tomoe Ishihara ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Photoreceptor Cell ◽  
Light Exposure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Intraperitoneal Administration ◽  
Binding Activity ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Fluorescent Light ◽  
Cell Degeneration

We examined the cytoprotective effect of quercetin via activator protein (AP-1) and the heat shock protein 70 (Hsp70) pathway against light-induced retinal degeneration in rats. Quercetin was administered intraperitoneally to Sprague-Dawley rats for seven days before light exposure to intense white fluorescent light (3000 lux) for 24 h. Light-induced retinal damage was determined by the number of rows of photoreceptor cell nuclei, the microstructures of the rod outer segments and retinal pigment epithelium, and terminal deoxynucleotidyl transferase (TdT)-mediated 2'-Deoxyuridine-5'-triphosphate (dUTP) nick end labeling. To elucidate the cytoprotective mechanism of quercetin, expression levels were measured in the rat retinas of 8-hydroxy-deoxyguanosine (8-OHdG), a marker of oxidative stress; Hsp70; and transcription factor AP-1 transcription activity. Pretreatment with quercetin inhibited light-induced photoreceptor cellular apoptosis and subsequent retinal degeneration in rats. 8-OHdG and Hsp70 protein expressions were up-regulated markedly by light exposure and suppressed by quercetin pretreatment. The results of an electrophoretic mobility shift assay showed that AP-1-binding activity was activated by light exposure, and binding of c-Fos and c-Jun, but not JunB, mediated the binding activity. Intraperitoneal administration of quercetin decreases photooxidative damage in the retina and mediates cytoprotection against light-induced photoreceptor cell degeneration in rats. Suppression of the heterodimeric combination of c-Jun and c-Fos proteins at the AP-1 binding site is highly involved in quercetin-mediated cytoprotection.

scholarly journals A Rare Case of Stargardt’s Disease

2021 ◽  
Vol 48 (2) ◽  
pp. 76-80
Author(s):  
I. Mermeklieva ◽  
K. Kamenarova
Keyword(s):  
Pigment Epithelium ◽  
Fundus Autofluorescence ◽  
Retinal Pigment ◽  
Correct Diagnosis ◽  
The Other ◽  
Missense Mutations ◽  
Full Field ◽  
Stargardt's Disease ◽  
Therapeutic Behavior ◽  
Stargardt’S Disease

Abstract Objective To describe a clinical case of rare eye diseases – Stargardt’s disease. Material and methods: A detailed clinical examination, fundus autofluorescence, optical coherence tomography and electrophysiological studies were performed. The clinical diagnosis was also genetically confirmed. Results A classic Stargardt’s disease phenotype was found in a 10-year old boy with decreased visual acuity, atrophy of the photoreceptors and retinal pigment epithelium layers in the macula, plus hypoautofluorescence in the fovea. In full-field ERG there was no diffuse cone involvement. Multifocal ERG demonstrated a lower cone activity in the area of the central macula in both eyes, which is characteristic for hereditary maculopathies and differentiates them from cone-rod dystrophies, in which generalized damage of the photoreceptors in the retina may be observed. The genetic studies identified two missense mutations: c.3113C> T (p.Ala1038Val) and c.1622T> C (p.Leu541Pro) in a cis-position and a missense mutation c.2588G> C (p.Gly863Ala) in the other allele of ABCA4 gene. The two pathogenic variants c.3113C> T and c.1622T> C formed a complex allele p. [A1038V; L541P], which was found in the genome of the asymptomatic mother. The other mutation c.2588G> C affects a highly conserved amino acid from the ABCA4 protein (p.Gly863Ala) and was inherited from the patient’s clinically healthy father, who was a heterozygous carrier. Conclusion The comprehensive clinical, electrophysiological and genetic testing of patients with rare hereditary retinal dystrophies is essential for the correct diagnosis and the choice of therapeutic behavior.

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