نتایج جستجو برای: ضریب PERG

تعداد نتایج: 61860  

Journal: :Investigative ophthalmology & visual science 2013
Michael R Banitt Lori M Ventura William J Feuer Eleonore Savatovsky Gabriel Luna Olga Shif Brandon Bosse Vittorio Porciatti

PURPOSE We determined the time lag between loss of retinal ganglion cell function and retinal nerve fiber layer (RNFL) thickness. METHODS Glaucoma suspects were followed for at least four years. Patients underwent pattern electroretinography (PERG), optical coherence tomography (OCT) of the RNFL, and standard automated perimetry testing at 6-month intervals. Comparisons were made between chan...

Journal: :Investigative ophthalmology & visual science 2011
Sebastian F N Bode Thomas Jehle Michael Bach

PURPOSE Early detection of glaucoma remains a challenging problem and needs long-term, prospective studies. The pattern electroretinogram (PERG) directly reflects retinal ganglion cell function. The PERG was evaluated by extending a prospective study of patients with ocular hypertension and evaluated amplitude, PERG ratio, peak time, and trends thereof. METHODS One hundred twenty eyes of 64 p...

Journal: :Investigative ophthalmology & visual science 2013
Dunja Preiser Wolf A Lagrèze Michael Bach Charlotte M Poloschek

PURPOSE Photopic negative response (PhNR) and pattern electroretinogram (PERG) are electrophysiological markers of retinal ganglion cell function; both are reduced in glaucoma. We compared PhNR and PERG in different stages of the disease. METHODS Eleven eyes with preperimetric glaucoma (glaucomatous optic disc with normal field); 18 with manifest glaucoma; and 26 normals were included. We obt...

Journal: :Investigative ophthalmology & visual science 2002
David F Garway-Heath Graham E Holder Fred W Fitzke Roger A Hitchings

PURPOSE To evaluate the relationship between electrophysiological, psychophysical, and structural measurements in normal and glaucomatous eyes and to test the hypothesis that there is a continuous structure-function relationship between ganglion cell numbers and visual field sensitivity. METHODS Thirty-four normal subjects and 40 patients with glaucoma were examined with the pattern electrore...

Journal: :Investigative ophthalmology & visual science 1987
N S Peachey W H Seiple

Contrast thresholds for the pattern electroretinogram (PERG) were measured using lock-in amplifier retrieval of the retinal signal and a swept contrast display. Contrast sensitivity functions (CSF) developed from these PERG contrast thresholds were compared with those established psychophysically under identical stimulus conditions. Whereas the PERG CSF showed a band-pass characteristic across ...

2018
Shresta Patangay Zahra Derafshi Thasarat S. Vajaranant Jason C. Park Elham Ghahari J. Jason McAnany John R. Hetling

Purpose The pattern electroretinogram (pERG) response reflects, in part, ganglion cell function. However, probing retinal ganglion cell (RGC) function in the mid- and far peripheral retina is difficult with conventional flat-panel pERG stimulus sources. A pattern stimulus source is presented for probing the peripheral retina. Peripheral pERG (ppERG) responses were evaluated versus luminance, re...

Journal: :Investigative ophthalmology & visual science 2012
Tsung-Han Chou Vittorio Porciatti

PURPOSE To compare the bioelectric field associated with the pattern electroretinogram (PERG) with that of the flash electroretinogram (FERG) in the mouse. METHODS PERGs and FERGs were recorded from each eye in 32 C57BL/6J mice using corneal silver loops referenced to a subcutaneous needle on the back of the head. PERG stimuli were horizontal gratings of 0.05 cycles per degree and 98% contras...

2017
Alberto Mavilio Dario Sisto Paolo Ferreri Nicola Cardascia Giovanni Alessio

PURPOSE A significant variability of the second harmonic (2ndH) phase of steady-state pattern electroretinogram (SS-PERG) in intrasession retest has been recently described in glaucoma patients (GP), which has not been found in healthy subjects. To evaluate the reliability of phase variability in retest (a procedure called RE-PERG or REPERG) in the presence of cataract, which is known to affect...

Journal: :Investigative ophthalmology & visual science 2015
Clara L Afonso Ali S Raza André C Kreuz Kenzo Hokazono Leonardo P Cunha Maria K Oyamada Mário L R Monteiro

PURPOSE We evaluated the ability of transient pattern electroretinogram (PERG) parameters to differentiate between eyes with visual field (VF) loss and resolved papilledema from pseudotumor cerebri syndrome (PTC) and controls, to compare PERG and optical coherence tomography (OCT) with regard to discrimination ability, and to assess the correlation between PERG, frequency domain OCT (FD-OCT), a...

Journal: :Investigative ophthalmology & visual science 2009
Mário L R Monteiro Leonardo P Cunha Luciana V F Costa-Cunha Otacílio O Maia Maria K Oyamada

PURPOSE To evaluate the relationship between pattern electroretinogram (PERG) amplitude, macular and retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), and visual field (VF) loss on standard automated perimetry (SAP) in eyes with temporal hemianopia from chiasmal compression. METHODS Forty-one eyes from 41 patients with permanent temporal VF defects from chiasma...

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