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Vittorio Porciatti - One of the best experts on this subject based on the ideXlab platform.

  • physiologic significance of steady state pattern Electroretinogram losses in glaucoma clues from simulation of abnormalities in normal subjects
    Journal of Glaucoma, 2009
    Co-Authors: Vittorio Porciatti, Lori M Ventura
    Abstract:

    PurposeTo better understand pathophysiologic mechanisms underlying pattern Electroretinogram (PERG) losses in glaucoma by simulating either retinal ganglion cell (RGC) dysfunction or RGC loss in normal subjects.Materials and MethodsThe steady-state PERG has been recorded in 10 normal subjects (mean

  • the pattern Electroretinogram as a tool to monitor progressive retinal ganglion cell dysfunction in the dba 2j mouse model of glaucoma
    Investigative Ophthalmology & Visual Science, 2007
    Co-Authors: Vittorio Porciatti, Maher Saleh, M Nagaraju
    Abstract:

    Purpose To determine the baseline characteristics, reliability and dynamic range of the pattern Electroretinogram (PERG) as a tool to monitor progressive RGC dysfunction in the DBA/2J mouse model of glaucoma with spontaneously elevated intraocular pressure (IOP).

  • restoration of retinal ganglion cell function in early glaucoma after intraocular pressure reduction a pilot study
    Ophthalmology, 2005
    Co-Authors: Lori M Ventura, Vittorio Porciatti
    Abstract:

    Purpose To investigate the changes of pattern Electroretinogram (PERG) after intraocular pressure lowering in glaucoma patients and normal controls. Design Interventional retrospective cross-sectional study. Participants Twenty-five patients (49 eyes) with ocular hypertension or glaucoma undergoing topical treatment to lower IOP served as a study group; 22 patients (44 eyes) with ocular hypertension or glaucoma observed without treatment served as a control group for treated glaucoma patients; 9 normal subjects (18 eyes) receiving a 250-mg acetazolamide tablet served as a second study group; and 17 normal subjects (34 eyes) from a previous study served as a second control group for treated normal subjects. Method Pattern Electroretinograms were recorded simultaneously from both eyes using skin electrodes and automated analysis. Visual field (VF) analyses were performed with white-on-white standard automated perimetry (SAP). Intraocular pressure was measured with Goldmann applanation tonometry; central corneal thickness was measured with pachymetry. Main outcome measures Pattern Electroretinogram amplitude (microvolts), phase (π rads), and test–retest variability (test 2–to–test 1 ratio, in decibels), SAP mean deviation (decibels), and IOP (millimeters of mercury). Results In 56% of right eyes and 21% of left eyes of the treated glaucoma subgroup, the PERG amplitude and/or phase improved beyond the 95% confidence intervals of the test–retest variability of the untreated glaucoma control group. Pattern Electroretinogram improvement with IOP lowering occurred in both high- and low-tension glaucoma eyes. Eyes with severely impaired VFs showed little improvement in PERG; however, eyes of normal subjects treated with acetazolamide did not show significant PERG changes relative to the test–retest variability of normal controls. Conclusions Retinal ganglion cell function can be at least partially restored after IOP reduction in glaucomatous eyes with early VF impairment.

  • Normative data for a user-friendly paradigm for pattern Electroretinogram recording.
    Ophthalmology, 2004
    Co-Authors: Vittorio Porciatti, Lori M Ventura
    Abstract:

    Purpose To provide normative data for a user-friendly paradigm for the pattern Electroretinogram (PERG) optimized for glaucoma screening (PERGLA).

  • guidelines for basic pattern electroretinography recommendations by the international society for clinical electrophysiology of vision
    Documenta Ophthalmologica, 1995
    Co-Authors: Michael F. Marmor, Graham E Holder, Vittorio Porciatti, Gary L Trick, Eberhart Zrenner
    Abstract:

    The pattern Electroretinogram is a retinal response that can be evoked by viewing an alternating grating or checkerboard. It is receiving increasing clinical and research attention because it can provide information about inner retinal cells and the macula. However, clinicians may have trouble choosing between different techniques for recording the Pattern Electroretinogram that have been described in the literature. The International Society for Clinical Electrophysiology of Vision has prepared guidelines for a basic pattern Electroretinogram recording procedure to aid new users in obtaining reliable responses and to encourage more uniformity among existing users.

Chan Kee Park - One of the best experts on this subject based on the ideXlab platform.

  • comparison of pattern Electroretinograms of glaucoma patients with parafoveal scotoma versus peripheral nasal step
    Scientific Reports, 2019
    Co-Authors: Kyoung In Jung, Sooji Jeon, Yong Chan Kim, Chan Kee Park
    Abstract:

    Retinal ganglion cells are distributed disproportionately with retinal eccentricity. Pattern Electroretinogram (PERG) stimuli resulted in reduced responses with more eccentric stimuli. Therefore, we investigated whether PERG amplitude is associated with the location of visual field (VF) defect in primary open-angle glaucoma. Data from Twenty-nine glaucoma patients with a parafoveal scotoma (PFS) within the central 10° of fixation, 23 glaucoma patients with a peripheral nasal step (PNS), and 27 normal control subjects were analyzed in this study. Electroretinograms (ERGs) were obtained using a commercial ERG stimulator (Neuro-ERG). The thickness of the ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. A lower N95 amplitude was observed in both PFS and PNS compared to the normal control (Both P < 0.001). The N95 amplitude of the PFS group was significantly lower than that of the PNS group (P = 0.034). Average GCIPL thickness correlated positively with N95 amplitude (r = 0.368, P = 0.002), but did not correlate significantly with global mean sensitivity (r = 0.228, P = 0.073) or mean deviation on 24-2 standard automated perimetry (r = 0.173, P = 0.176). In conclusion, parafoveal VF defects were associated with the lower PERG amplitude. Therefore, it is necessary to take into account the location of VF defects in evaluating PERGs of glaucoma patients.

  • Comparison of pattern Electroretinograms of glaucoma patients with parafoveal scotoma versus peripheral nasal step
    Nature Publishing Group, 2019
    Co-Authors: Kyoung In Jung, Sooji Jeon, Yong Chan Kim, Chan Kee Park
    Abstract:

    Abstract Retinal ganglion cells are distributed disproportionately with retinal eccentricity. Pattern Electroretinogram (PERG) stimuli resulted in reduced responses with more eccentric stimuli. Therefore, we investigated whether PERG amplitude is associated with the location of visual field (VF) defect in primary open-angle glaucoma. Data from Twenty-nine glaucoma patients with a parafoveal scotoma (PFS) within the central 10° of fixation, 23 glaucoma patients with a peripheral nasal step (PNS), and 27 normal control subjects were analyzed in this study. Electroretinograms (ERGs) were obtained using a commercial ERG stimulator (Neuro-ERG). The thickness of the ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. A lower N95 amplitude was observed in both PFS and PNS compared to the normal control (Both P 

Lori M Ventura - One of the best experts on this subject based on the ideXlab platform.

  • physiologic significance of steady state pattern Electroretinogram losses in glaucoma clues from simulation of abnormalities in normal subjects
    Journal of Glaucoma, 2009
    Co-Authors: Vittorio Porciatti, Lori M Ventura
    Abstract:

    PurposeTo better understand pathophysiologic mechanisms underlying pattern Electroretinogram (PERG) losses in glaucoma by simulating either retinal ganglion cell (RGC) dysfunction or RGC loss in normal subjects.Materials and MethodsThe steady-state PERG has been recorded in 10 normal subjects (mean

  • restoration of retinal ganglion cell function in early glaucoma after intraocular pressure reduction a pilot study
    Ophthalmology, 2005
    Co-Authors: Lori M Ventura, Vittorio Porciatti
    Abstract:

    Purpose To investigate the changes of pattern Electroretinogram (PERG) after intraocular pressure lowering in glaucoma patients and normal controls. Design Interventional retrospective cross-sectional study. Participants Twenty-five patients (49 eyes) with ocular hypertension or glaucoma undergoing topical treatment to lower IOP served as a study group; 22 patients (44 eyes) with ocular hypertension or glaucoma observed without treatment served as a control group for treated glaucoma patients; 9 normal subjects (18 eyes) receiving a 250-mg acetazolamide tablet served as a second study group; and 17 normal subjects (34 eyes) from a previous study served as a second control group for treated normal subjects. Method Pattern Electroretinograms were recorded simultaneously from both eyes using skin electrodes and automated analysis. Visual field (VF) analyses were performed with white-on-white standard automated perimetry (SAP). Intraocular pressure was measured with Goldmann applanation tonometry; central corneal thickness was measured with pachymetry. Main outcome measures Pattern Electroretinogram amplitude (microvolts), phase (π rads), and test–retest variability (test 2–to–test 1 ratio, in decibels), SAP mean deviation (decibels), and IOP (millimeters of mercury). Results In 56% of right eyes and 21% of left eyes of the treated glaucoma subgroup, the PERG amplitude and/or phase improved beyond the 95% confidence intervals of the test–retest variability of the untreated glaucoma control group. Pattern Electroretinogram improvement with IOP lowering occurred in both high- and low-tension glaucoma eyes. Eyes with severely impaired VFs showed little improvement in PERG; however, eyes of normal subjects treated with acetazolamide did not show significant PERG changes relative to the test–retest variability of normal controls. Conclusions Retinal ganglion cell function can be at least partially restored after IOP reduction in glaucomatous eyes with early VF impairment.

  • Normative data for a user-friendly paradigm for pattern Electroretinogram recording.
    Ophthalmology, 2004
    Co-Authors: Vittorio Porciatti, Lori M Ventura
    Abstract:

    Purpose To provide normative data for a user-friendly paradigm for the pattern Electroretinogram (PERG) optimized for glaucoma screening (PERGLA).

Kyoung In Jung - One of the best experts on this subject based on the ideXlab platform.

  • comparison of pattern Electroretinograms of glaucoma patients with parafoveal scotoma versus peripheral nasal step
    Scientific Reports, 2019
    Co-Authors: Kyoung In Jung, Sooji Jeon, Yong Chan Kim, Chan Kee Park
    Abstract:

    Retinal ganglion cells are distributed disproportionately with retinal eccentricity. Pattern Electroretinogram (PERG) stimuli resulted in reduced responses with more eccentric stimuli. Therefore, we investigated whether PERG amplitude is associated with the location of visual field (VF) defect in primary open-angle glaucoma. Data from Twenty-nine glaucoma patients with a parafoveal scotoma (PFS) within the central 10° of fixation, 23 glaucoma patients with a peripheral nasal step (PNS), and 27 normal control subjects were analyzed in this study. Electroretinograms (ERGs) were obtained using a commercial ERG stimulator (Neuro-ERG). The thickness of the ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. A lower N95 amplitude was observed in both PFS and PNS compared to the normal control (Both P < 0.001). The N95 amplitude of the PFS group was significantly lower than that of the PNS group (P = 0.034). Average GCIPL thickness correlated positively with N95 amplitude (r = 0.368, P = 0.002), but did not correlate significantly with global mean sensitivity (r = 0.228, P = 0.073) or mean deviation on 24-2 standard automated perimetry (r = 0.173, P = 0.176). In conclusion, parafoveal VF defects were associated with the lower PERG amplitude. Therefore, it is necessary to take into account the location of VF defects in evaluating PERGs of glaucoma patients.

  • Comparison of pattern Electroretinograms of glaucoma patients with parafoveal scotoma versus peripheral nasal step
    Nature Publishing Group, 2019
    Co-Authors: Kyoung In Jung, Sooji Jeon, Yong Chan Kim, Chan Kee Park
    Abstract:

    Abstract Retinal ganglion cells are distributed disproportionately with retinal eccentricity. Pattern Electroretinogram (PERG) stimuli resulted in reduced responses with more eccentric stimuli. Therefore, we investigated whether PERG amplitude is associated with the location of visual field (VF) defect in primary open-angle glaucoma. Data from Twenty-nine glaucoma patients with a parafoveal scotoma (PFS) within the central 10° of fixation, 23 glaucoma patients with a peripheral nasal step (PNS), and 27 normal control subjects were analyzed in this study. Electroretinograms (ERGs) were obtained using a commercial ERG stimulator (Neuro-ERG). The thickness of the ganglion cell-inner plexiform layer (GCIPL) was measured using spectral-domain optical coherence tomography. A lower N95 amplitude was observed in both PFS and PNS compared to the normal control (Both P 

Gordon T Plant - One of the best experts on this subject based on the ideXlab platform.

  • photopsia and a temporal visual field defect
    Survey of Ophthalmology, 2016
    Co-Authors: Marcela Marsiglia, Jeffery G Odel, Danielle S Rudich, S Tsang, Gordon T Plant
    Abstract:

    A 30-year-old woman presented with intermittent photopsia, a temporal visual field defect below the horizontal in her left eye, and flu-like symptoms. Slit-lamp and fundus examinations were unremarkable. Humphrey 30-2 threshold perimetry and 120-point screening visual field demonstrated blind spot enlargement of the left eye and a normal field in the right eye. Fundus autofluorescence, optical coherence tomography of the macula, full-field Electroretinogram, electrooculogram, and multifocal Electroretinogram were normal. Swept-source optical coherence tomography scan of the left optic nerve showed an intact outer retina, a remarkably thinned nerve fiber layer nasally, and peripapillary vitreous traction. Goldmann kinetic perimetry revealed a sector-shaped dense defect breaking out from the blind spot to the temporal periphery just below the horizontal in the left eye. The patient had nasal hypoplasia of the optic nerve and peripapillary vitreous traction.