scholarly journals Objective visual field determination using visual evoked potentials. A basic study on normal subjects.

1989 ◽  
Vol 17 ◽  
pp. 58-61
Author(s):  
Tomoe HAYAKAWA ◽  
Hisashi KIMURA ◽  
Jun TSUTSUI
Keyword(s):  
Visual Field ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Basic Study ◽  
Visual Evoked

scholarly journals Integrated electrophysiological evaluation in early normal-tension glaucoma

2016 ◽  
Vol 1 (2) ◽  
pp. 79-88
Author(s):  
Dario Messenio ◽  
Giuseppe Marano ◽  
Elia Biganzoli
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Optic Nerve Head ◽  
Pattern Electroretinogram ◽  
Normal Subjects ◽  
Visual Field Defects ◽  
Control Group ◽  
Visual Evoked

Purpose: To evaluate the variations of intraocular pressure (IOP), morphometric optic nerve head characteristic, perimetric indices and electrophysiological parameters (pattern electroretinogram and visual evoked potentials) before and after topical IOP lowering in patients with early normal-tension glaucoma.Methods: we evaluated 38 eyes of 20 patients with IOP < 21 mmHg, initial glaucomatous optic neuropathy (valued with HRT: retinal nerve fiber layer thickness (RNFL) and linear cup/disk ratio (linear C/D ratio)), minimal visual field defects (Octopus 101: G2 program), best correct visual acuity more than 15/20 and pathological electrophysiological parameters (valued with pattern electroretinogram (PERG) and visual evoked potentials (VEPs)), free of systemic or other ocular diseases. All parameters were evaluated at the beginning of the study (T0) and after 12 months of therapy (T12). A randomized normal control group (27 eyes of 14 subjects) with apparent larger disc cupping underwent all exams at initial of study (T0) and after 12 months (T12).Results: Among electrophysiological parameters, at the beginning of the study NTG P100 VEPs latency is slightly increased and P100 amplitude is reduced compared to normal subjects. There are not significant variations after 12 months. P50 PERG latency in NTG is quite similar respect normal and do not modify after therapy. P50N95 complex PERG amplitude in NTG is reduced compared to normal subjects and slightly increases after 12 months (1.8 vs 1.5 ; 2.4 vs 1.9 micronvolts, with different checkboard spatial frequency). Cortical retinal time (CRT) is slightly delayed in NTG and does not modify. Among visual field indices, MD and CLV is slightly higher in NTG and do not significantly modify after therapy. Among morphometric optic nerve head characteristics, linear C/D and RNFL thickness are quite similar in NTG and do not modify. IOP is quite similar between NTG and control group and modifies in NTG after therapy.Conclusion: In a viewpoint of an integrated diagnostic, electrophysiological tests (VEPs and PERG) could provide a more sensitive measure of retinal ganglion cell integrity and help to distinguish between early normal-pressure glaucoma patients with no or minimal visual field alterations and normal subjects with apparent larger disc cupping.

Nonlinear Analysis of Visual Evoked Potentials Elicited by Color Stimulation

1997 ◽  
Vol 36 (04/05) ◽  
pp. 315-318 ◽  
Author(s):  
K. Momose ◽  
K. Komiya ◽  
A. Uchiyama
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Second Order ◽  
First Order ◽  
The Relationship ◽  
Perceived Color ◽  
Second Order Nonlinearity ◽  
Visual Evoked

Abstract:The relationship between chromatically modulated stimuli and visual evoked potentials (VEPs) was considered. VEPs of normal subjects elicited by chromatically modulated stimuli were measured under several color adaptations, and their binary kernels were estimated. Up to the second-order, binary kernels obtained from VEPs were so characteristic that the VEP-chromatic modulation system showed second-order nonlinearity. First-order binary kernels depended on the color of the stimulus and adaptation, whereas second-order kernels showed almost no difference. This result indicates that the waveforms of first-order binary kernels reflect perceived color (hue). This supports the suggestion that kernels of VEPs include color responses, and could be used as a probe with which to examine the color visual system.

scholarly journals Cortical Contrast Processing in Retinitis Pigmentosa: Evidence of PVEPs Spatial Functions

2020 ◽  
Vol 10 (4) ◽  
pp. 1010-1019
Author(s):  
Rafael Mancebo-Azor ◽  
José Antonio Sáez-Moreno ◽  
José Manuel Rodríguez-Ferrer
Keyword(s):  
Retinitis Pigmentosa ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Pattern Reversal ◽  
Check Size ◽  
Low Contrast ◽  
Control Subjects ◽  
The Right ◽  
Visual Evoked

Objective: To study the effect of check width size of the stimuli on the amplitude and latency of the P100 component of visual evoked potentials recorded in patients with retinitis pigmentosa (RP). Methods: Pattern reversal visual evoked potentials (PVEPs) were recorded in 16 RP patients and 20 visually normal subjects. Pattern reversal stimuli with five different check widths and 100% of contrast were projected in the right eye of both patients and control subjects. PVEPs induced by stimuli with 78%, 16%, and 6% of contrast were also recorded in 10 of the control subjects. Results: In RP patients, the amplitude of P100 was smaller than controls in all check sized used and the peak P100 amplitude was obtained with a larger check width than in controls. P100 was also delayed in RP patients in all check sizes studied. The P100 amplitude- and latency-check size functions of RP patients were like those found in control subjects with low contrast stimuli of 16% and 6%. Conclusion: The PVEPs spatial functions of RP patients show quantitative and qualitative changes, suggesting disease induced alteration in the neural processing of stimulus contrast.

Multifocal visual-evoked potentials in patients with schizophrenia during treatment

2011 ◽  
Vol 23 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Mariko Yamada ◽  
Eiichi Yukawa ◽  
Futoshi Taketani ◽  
Toyoaki Matsuura ◽  
Yoshiaki Hara
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Subject Group ◽  
Recording Apparatus ◽  
Multifocal Visual Evoked Potentials ◽  
Psychotropic Agents ◽  
Schizophrenic Patients ◽  
Conventional Perimetry ◽  
Visual Evoked

Aim: Investigation of responses of multifocal visual-evoked potentials (mfVEPs) in schizophrenic patients under treatment in whom no abnormality was detected on the conventional perimetry.Methods: Recordings of mfVEPs were performed in 31 schizophrenic patients and 30 normal subjects using a VERIS Junior Science recording apparatus (Mayo, Aichi, Japan). Responses from eight sites in each subject were divided into four quadrants (superior and inferior temporal quadrants, and superior and inferior nasal quadrants). In each quadrant, two response waves were grouped and averaged, and the latency and amplitude of main waveforms that appeared near 100 ms were evaluated.Results: The peak latency was about 7–9 ms prolonged and the amplitude was reduced by about 2–5 nV/deg2 in the schizophrenic patient group compared to those in the normal subject group, and significant differences were noted in both parameters in all quadrants.Conclusion: In schizophrenic patients under treatment with psychotropic agents, prolongation of the latency and amplitude reduction were noted in mfVEPs even though no abnormality was detected on the conventional perimetry.

Steady-State Visual-Evoked Potentials in Headache: Diagnostic Value in Migraine and Tension-Type Headache Patients

Cephalalgia ◽  
1999 ◽  
Vol 19 (1) ◽  
pp. 23-26 ◽  
Author(s):  
M de Tommaso ◽  
V Sciruicchio ◽  
M Guido ◽  
G Sasanelli ◽  
F Puca
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Stimulation ◽  
Normal Subjects ◽  
Tension Type Headache ◽  
Brain Response ◽  
Mean Values ◽  
Type Headache ◽  
Headache Patients ◽  
Visual Evoked

We tested the hypothesis that migraine and tension-type headache are separate disorders based on visual evoked potentials. We recruited 120 migraine without aura patients (MwoA), 64 tension-type headache patients (TTH), and 51 healthy controls. We performed discriminant analysis combined with a stepwise selection of predictors. Mean values of the F1 component were significantly increased over Fp1, C3, P4, O2 and O1 electrodes in MwoA and TTH patients compared with normal subjects. Only the control subjects were correctly distinguished. The increased brain response to visual stimulation detected in both MwoA and TTH may suggest a common neuronal dysfunction in the two headache subtypes.

scholarly journals Inflammatory optic neuropathy in Behçet’s disease

Reumatismo ◽  
2016 ◽  
Vol 67 (4) ◽  
pp. 156 ◽  
Author(s):  
M. S. Khanfir ◽  
N. Belfeki ◽  
F. Said ◽  
T. Ben Salem ◽  
I. Ben Ghorbel ◽  
...  
Keyword(s):  
Visual Field ◽  
Evoked Potentials ◽  
Behçet’S Disease ◽  
Visual Evoked Potentials ◽  
Optic Neuropathy ◽  
Behcet’S Disease ◽  
Behçet's Disease ◽  
Clinical Manifestations ◽  
Behcet's Disease ◽  
Visual Evoked

Inflammatory optic neuropathy (ON) is a rare event in Behçet’s disease (BD). We report herein a series of ten BD Tunisian patients with ON and describe its clinical features among them. A retrospective review of BD patients (International Study Group for BD criteria) was performed. The patients were divided into two groups: those presenting an inflammatory ON, and those none. The diagnosis of inflammatory ON was based on the clinical examination, visual field and visual evoked potentials. We analyzed the characteristics of the two groups. Ten patients (2.3%) presented an inflammatory ON among our 440 patients. Inflammatory ON was inaugural in 8 cases. Clinical manifestations were as follows: blurred vision (7 cases) and periorbital pain (3 cases). In two cases, the patients did not complain from ophthalmological symptoms. The fundus revealed a papilledema (2 cases), papillary pallor (4 cases), and was normal in 5 cases. Visual field realized in only three patients showed a scotoma in all cases. Visual evoked potentials revealed increased latency in all cases. All patients received corticosteroids associated to an immunosuppressive agent. The comparative study between the two groups revealed that inflammatory ON was significantly more associated to neurological involvement (p&lt;0.0001) and that the disease was more severe in the ON group (p&lt;0.0001). Inflammatory ON in BD is rare and may occur at an early stage of the clinical course of the disease. Its prevalence is certainly underestimated. A systematic visual evoked potential may be interesting as a screening tool.

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