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Electroretinogram

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https://www.readbyqxmd.com/read/28101399/stimulus-evoked-outer-segment-changes-occur-before-the-hyperpolarization-of-retinal-photoreceptors
#1
Yiming Lu, Benquan Wang, David R Pepperberg, Xincheng Yao
Transient retinal phototropism (TRP) has been predominantly observed in rod photoreceptors activated by oblique visible light stimulation. Dynamic confocal microscopy and optical coherence tomography (OCT) have revealed rod outer segment (ROS) movement as the physical source of TRP. However, the physiological source of ROS movement is still not well understood. In this study, concurrent near-infrared imaging of TRP and electroretinogram (ERG) measurement of retinal electrophysiology revealed that ROS movement occurs before the onset of the ERG a-wave, which is known to reflect the hyperpolarization of retinal photoreceptors...
January 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28099524/role-of-myo-nog-cells-in-neuroprotection-evidence-from-the-light-damaged-retina
#2
Alice Brandli, Jacquelyn Gerhart, Christopher K Sutera, Sivaraman Purushothuman, Mindy George-Weinstein, Jonathan Stone, Arturo Bravo-Nuevo
PURPOSE: To identify Myo/Nog cells in the adult retina and test their role in protecting retinal photoreceptors from light damage. METHODS: Light damage was induced by exposing albino rats raised in dim cyclic light to 1000 lux light for 24 hours. In one group of rats, Myo/Nog cells were purified from rat brain tissue by magnetic cell sorting following binding of the G8 monoclonal antibody (mAb). These cells were injected into the vitreous humour of the eye within 2 hours following bright light exposure...
2017: PloS One
https://www.readbyqxmd.com/read/28097047/quantifying-the-on-and-off-contributions-to-the-flash-erg-with-the-discrete-wavelet-transform
#3
Mathieu Gauvin, Maja Sustar, John M Little, Jelka Brecelj, Jean-Marc Lina, Pierre Lachapelle
PURPOSE: Discrete wavelet transform (DWT) analyses suggest that the 20- and 40-Hz components of the short-flash photopic electroretinogram (ERG) are closely related to the ON and OFF pathways, respectively. With the DWT, we examined how the ERG ON and OFF components are modulated by the stimulus intensity and/or duration. METHODS: Discrete wavelet transform descriptors (20, 40 Hz and 40:20-Hz ratio) were extracted from ERGs evoked to 25 combinations of flash durations (150-5 ms) and strengths (0...
January 2017: Translational Vision Science & Technology
https://www.readbyqxmd.com/read/28076567/full-field-electroretinogram-recorded-with-skin-electrodes-in-normal-adults
#4
Arthur Gustavo Fernandes, Solange Rios Salomão, Josenilson Martins Pereira, Adriana Berezovsky
Purpose: Alternative recording methods have been tested to allow the electroretinogram (ERG) recording in uncooperative patients and/or patients with palpebral alterations, including recordings with skin electrodes. The purpose of this study was to compare ERG recorded with skin electrodes and well-established microfiber electrodes and to determine normative values of ERG parameters for recording with skin electrodes. Methods: Fifty healthy volunteers (17-26 years; mean 20...
November 2016: Arquivos Brasileiros de Oftalmologia
https://www.readbyqxmd.com/read/28055012/aif-independent-parthanatos-in-the-pathogenesis-of-dry-age-related-macular-degeneration
#5
Ki-Hong Jang, Yun-Ju Do, Dongwon Son, Eunji Son, Jun-Sub Choi, Eunhee Kim
Cell death of retinal pigment epithelium (RPE) is characterized as an essential late-stage phenomenon of dry age-related macular degeneration (AMD). The aim of this study was to elucidate the molecular mechanism underlying RPE cell death after exposure to oxidative stress, which occurs often because of the anatomical location of RPE cells. ARPE-19, an established RPE cell line, exhibited necrotic features involving poly (ADP-ribose) polymerase-1 (PARP-1) activation in response to hydrogen peroxide (H2O2). ARPE-19 cells were resistant to H2O2 when PARP-1 was depleted using siRNA or inhibited by a pharmacological inhibitor of PARP-1, olaparib...
January 5, 2017: Cell Death & Disease
https://www.readbyqxmd.com/read/28053051/rom1-converts-y141c-prph2-associated-pattern-dystrophy-to-retinitis-pigmentosa
#6
Shannon M Conley, Michael W Stuck, Jamie N Watson, Muna I Naash
Mutations in peripherin 2 (PRPH2), also known as retinal degeneration slow/RDS, lead to various retinal degenerations including retinitis pigmentosa (RP) and macular/pattern dystrophy (MD/PD). PRPH2-associated disease is often characterized by a phenotypic variability even within families carrying the same mutation, raising interest in potential modifiers. PRPH2 oligomerizes with its homologue rod outer segment (OS) membrane protein 1 (ROM1), and non-pathogenic PRPH2/ROM1 mutations, when present together, lead to digenic RP...
January 4, 2017: Human Molecular Genetics
https://www.readbyqxmd.com/read/28038685/grafted-c-kit-ssea1-eye-wall-progenitor-cells-delay-retinal-degeneration-in-mice-by-regulating-neural-plasticity-and-forming-new-graft-to-host-synapses
#7
Xi Chen, Zehua Chen, Zhengya Li, Chen Zhao, Yuxiao Zeng, Ting Zou, Caiyun Fu, Xiaoli Liu, Haiwei Xu, Zheng Qin Yin
BACKGROUND: Despite diverse pathogenesis, the common pathological change observed in age-related macular degeneration and in most hereditary retinal degeneration (RD) diseases is photoreceptor loss. Photoreceptor replacement by cell transplantation may be a feasible treatment for RD. The major obstacles to clinical translation of stem cell-based cell therapy in RD remain the difficulty of obtaining sufficient quantities of appropriate and safe donor cells and the poor integration of grafted stem cell-derived photoreceptors into the remaining retinal circuitry...
December 30, 2016: Stem Cell Research & Therapy
https://www.readbyqxmd.com/read/28035520/test-retest-reliability-of-the-multifocal-photopic-negative-response
#8
Anthony W Van Alstine, Suresh Viswanathan
PURPOSE: To assess the test-retest reliability of the multifocal photopic negative response (mfPhNR) of normal human subjects. METHODS: Multifocal electroretinograms were recorded from one eye of 61 healthy adult subjects on two separate days using a Visual Evoked Response Imaging System software version 4.3 (EDI, San Mateo, California). The visual stimulus delivered on a 75-Hz monitor consisted of seven equal-sized hexagons each subtending 12° of visual angle...
December 29, 2016: Documenta Ophthalmologica. Advances in Ophthalmology
https://www.readbyqxmd.com/read/28010144/frosted-branch-angiitis-in-a-patient-with-typhoid-fever
#9
Mamta Agarwal, Jambulingam Malathi, Jyotirmay Biswas
Frosted branch angiitis (FBA), a rare form of retinal vasculitis presenting as bilateral perivascular sheathing, resembling the appearance of frosted tree branches in winter, was first reported by Ito et al.(1) in 1976, in a young immunocompetent boy. FBA predominantly affects healthy young patients, the youngest reported in an 11-month-old infant(2) and oldest in a 42-year-old patient.(3) Classical symptoms include sudden onset of blurred vision with floaters and photopsiae. Fundus examination shows widespread perivascular translucent sheathing affecting both arterioles and venules, more commonly latter...
December 23, 2016: Ocular Immunology and Inflammation
https://www.readbyqxmd.com/read/28007463/electroretinographic-anomalies-in-medicated-and-drug-free-patients-with-major-depression-tagging-the-developmental-roots-of-major-psychiatric-disorders
#10
Marc Hébert, Chantal Mérette, Thomas Paccalet, Anne-Marie Gagné, Michel Maziade
The retina is tagged as an approachable part of the brain due to its common embryonic origin and appears as a promising site of investigation for psychiatric disorders. Retinal function is assessed best with the electroretinogram (ERG), which was obtained in a large sample of patients with major depressive disorder and matched controls. ERG cone and rod luminance response functions were recorded in non-dilated eyes in 100 major depressive disorder patients (MDD) and 100 controls, (mean age of 42.8 and 40.9y...
December 19, 2016: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/27995607/longchain-polyunsaturated-fatty-acid-supplementation-in-preterm-infants
#11
REVIEW
Kwi Moon, Shripada C Rao, Sven M Schulzke, Sanjay K Patole, Karen Simmer
BACKGROUND: Controversy exists over whether longchain polyunsaturated fatty acids (LCPUFA) are essential nutrients for preterm infants because they may not be able to synthesise sufficient amounts of LCPUFA to meet the needs of the developing brain and retina. OBJECTIVES: To assess whether supplementation of formula milk with LCPUFA is safe and of benefit to preterm infants. The main areas of interest were the effects of supplementation on the visual function, development and growth of preterm infants...
December 20, 2016: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/27993590/prevalence-of-anti-retinal-antibodies-in-acute-zonal-occult-outer-retinopathy-azoor-a-comprehensive-review-of-25-cases
#12
Cynthia X Qian, Angeline Wang, David L DeMill, Thiran Jayasundera, Kari Branham, Maria Fernanda Abalem, Naheed Khan, John R Heckenlively
PURPOSE: To perform a comprehensive review and to investigate the presence and role of autoimmune antibodies in 25 cases of acute zonal occult outer retinopathy (AZOOR) identified using the classification originally proposed by J.Donald Gass. DESIGN: Observational case series METHODS: Setting: Institutional Study Population: Twenty-five patients were identified by characteristic symptoms (abrupt onset of photopsias, followed by large scotomata at or connected to the blind spot), ocular findings (paucity of pigmentary changes with no sign of vitreous inflammation and abnormal electroretinogram in at least one eye,) and a negative family history for retinitis pigmentosa...
December 16, 2016: American Journal of Ophthalmology
https://www.readbyqxmd.com/read/27992460/norbixin-protects-retinal-pigmented-epithelium-cells-and-photoreceptors-against-a2e-mediated-phototoxicity-in-vitro-and-in-vivo
#13
Valérie Fontaine, Elodie Monteiro, Elena Brazhnikova, Laëtitia Lesage, Christine Balducci, Louis Guibout, Laurence Feraille, Pierre-Paul Elena, José-Alain Sahel, Stanislas Veillet, René Lafont
The accumulation of N-retinylidene-N-retinylethanolamine (A2E, a toxic by-product of the visual pigment cycle) in the retinal pigment epithelium (RPE) is a major cause of visual impairment in the elderly. Photooxidation of A2E results in retinal pigment epithelium degeneration followed by that of associated photoreceptors. Present treatments rely on nutrient supplementation with antioxidants. 9'-cis-Norbixin (a natural diapocarotenoid, 97% purity) was prepared from Bixa orellana seeds. It was first evaluated in primary cultures of porcine retinal pigment epithelium cells challenged with A2E and illuminated with blue light, and it provided an improved photo-protection as compared with lutein or zeaxanthin...
2016: PloS One
https://www.readbyqxmd.com/read/27984836/-do-we-still-need-electrophysiology-in-ophthalmology
#14
H Tegetmeyer
Electrophysiological methods in clinical ophthalmology include the full-field electroretinogram (ERG) for assessment of outer and middle retinal layers, pattern ERG (PERG) for assessment of ganglion cell function, the electrooculogram (EOG) for assessment of retinal pigment epithelium function, as well as visual evoked potentials (VEP) for assessment of the visual pathway, including the optic nerve and visual cortex. Multifocal recording techniques for ERG and VEP are used for tests within selected areas of the visual field...
December 2016: Klinische Monatsblätter Für Augenheilkunde
https://www.readbyqxmd.com/read/27984356/structural-and-functional-monitoring-of-extramacular-cystoid-spaces-in-a-case-of-x-linked-retinoschisis-treated-with-acetazolamide
#15
Frederick T Collison, Gerald A Fishman
BACKGROUND: Carbonic anhydrase inhibitors (CAIs) have been shown to have a beneficial effect on cystoid macular edema in X-linked retinoschisis (XLRS) and other inherited retinal conditions. The effect of CAIs outside the macula has been less well studied. METHODS: Snellen visual acuity, spectral-domain optical coherence tomography (SD-OCT), kinetic visual field, and dark-adapted single-flash full-field electroretinogram (ERG) testing were all done at baseline and at least one follow-up visit...
December 13, 2016: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/27983731/whole-eye-transplantation-a-look-into-the-past-and-vision-for-the-future
#16
D Bourne, Y Li, C Komatsu, M R Miller, E H Davidson, L He, I A Rosner, H Tang, W Chen, M G Solari, J S Schuman, K M Washington
Blindness afflicts ~39 million people worldwide. Retinal ganglion cells are unable to regenerate, making this condition irreversible in many cases. Whole-eye transplantation (WET) provides the opportunity to replace diseased retinal ganglion cells, as well as the entire optical system and surrounding facial tissue, if necessary. Recent success in face transplantation demonstrates that this may be a promising treatment for what has been to this time an incurable condition. An animal model for WET must be established to further enhance our knowledge of nerve regeneration, immunosuppression, and technical aspects of surgery...
December 16, 2016: Eye
https://www.readbyqxmd.com/read/27974533/the-unusual-eyes-of-xenos-peckii-strepsiptera-xenidae-have-green-and-uv-sensitive-photoreceptors
#17
Marisano James, Sri Pratima Nandamuri, Aaron Stahl, Elke K Buschbeck
The highly specialized evolution of Strepsiptera has produced one of the most unusual eyes among mature insects, perhaps in line with their extremely complex and challenging life cycle. This relatively rare insect order is one of the few for which it has been unclear what spectral classes of photoreceptors any of its members may possess, an even more apt question given the nocturnal evolution of the group. To address this question, we performed electroretinograms on adult male Xenos peckii: we measured spectral responses to equi-quantal monochromatic light flashes of different wavelengths, and established VlogI relationships to calculate spectral sensitivities...
December 15, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27905344/concurrent-retinitis-pigmentosa-and-pigmented-paravenous-retinochoroidal-atrophy-phenotypes-in-the-same-patient
#18
Dhanashree Ratra, Dhileesh P Chandrasekharan, P Aruldas, Vineet Ratra
We report a unique case of a patient with retinitis pigmentosa (RP) phenotype in one eye and pigmented paravenous retinochoroidal atrophy (PPRCA) phenotype in the other eye. We describe in detail the symptoms, clinical findings, and investigations done for a 32-year-old Indian woman. This patient had phenotypical picture resembling typical RP in the right eye, with characteristic symptoms of night blindness and constricted field of vision and a nonrecordable electroretinogram (ERG). The left eye of the same patient revealed typical PPRCA phenotype, with no night blindness, normal field, and normal ERG...
October 2016: Indian Journal of Ophthalmology
https://www.readbyqxmd.com/read/27899086/closantel-a-veterinary-drug-with-potential-severe-morbidity-in-humans
#19
Seyed Ali Tabatabaei, Mohammad Soleimani, Mohammad Reza Mansouri, Ahmad Mirshahi, Bahman Inanlou, Mojtaba Abrishami, Ahmad Reza Pakrah, Hamideh Masarat
BACKGROUND: Closantel is a halogenated salicylanilide with a potent anti parasitic activity. It is widely used in management of parasitic infestation in animals, but is contraindicated in humans. CASE PRESENTATION: A 34-year-old man with depression was referred to our center with progressive loss of vision in both eyes 10 days after unintentional ingestion of three 500 mg tablets of Closantel. On fundus examination, left optic disc margin was blurred. His bilateral visual acuity was no light perception (NLP) despite prescribed IV erythropoietin injections 20,000 units daily for 3 days and 1gr intravenous methylprednisolone acetate for 3 days followed by 1 mg/kg oral prednisolone...
November 29, 2016: BMC Ophthalmology
https://www.readbyqxmd.com/read/27898981/macular-features-in-retinitis-pigmentosa-correlations-among-ganglion-cell-complex-thickness-capillary-density-and-macular-function
#20
Lisa Toto, Enrico Borrelli, Rodolfo Mastropasqua, Alfonso Senatore, Luca Di Antonio, Marta Di Nicola, Paolo Carpineto, Leonardo Mastropasqua
Purpose: To investigate correlations among macular ganglion cell complex (GCC) layer thickness, macular capillary density, and macular function in patients affected by retinitis pigmentosa (RP). Methods: Fourteen patients (28 eyes) with previous diagnosis of RP were enrolled. The diagnosis of these conditions was made based on both clinical features and electrophysiological examination. All patients underwent a complete ophthalmologic examination, including optical coherence tomography angiography (OCTA) and multifocal electroretinogram (mfERG)...
November 1, 2016: Investigative Ophthalmology & Visual Science
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