Jelka Brecelj

Jelka Brecelj
Ljubljana University Medical Centre | UMC · Clinic of Ophthalmology, Unit for visual electrophysiology

Research Professor

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88
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Publications

Publications (88)
Article
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Citation: Sajovic, J.; Meglič, A.; Fakin, A.; Brecelj, J.; Šuštar Habjan, M.; Hawlina, M.; Jarc Vidmar, M. Natural History of Stargardt Disease: The Longest Follow-Up Cohort Study. Abstract: Long-term natural history studies are important in rare disease research. This study aimed to assess electrophysiological and fundus autofluorescence (FAF) pro...
Article
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Aim Dysfunction of the retinal ganglion cells (RGC) can be detected by the pattern electroretinogram (PERG) as a reduction of the N95 amplitude, a decrease of the ratio between N95 and P50 amplitude and/or a shortening of P50 peak time. Additionally, the slope from the top of the P50 towards the N95 (P50–N95 slope) is less steep than in control sub...
Article
Background: A Slovenian three-generation family with 3 individuals with bilateral optic neuropathy and 2 unaffected relatives with a novel homoplasmic missense variant m.13042G > T (A236S) in the ND5 gene is described. A detailed phenotype at initial diagnosis and a follow-up of bilateral optic neuropathy progression is presented for 2 affected in...
Article
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Background We present the disease course and long-term follow-up of two patients who were phenotypically diagnosed with atypical Leber Hereditary Optic Neuropathy (LHON) 14 and 12 years ago, respectively, whereby whole exome sequencing revealed recently described recessive DNAJC30:c.152G>A 152 A>G (p.Tyr51Cys) homozygous pathogenic variant with sig...
Article
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Klinično elektrofiziološko testiranje vidnega sistema vključuje vrsto neinvazivnih testov, ki zagotavljajo objektivno oceno delovanja vidnega sistema. S snemanjem elektrookulografije (EOG), elektroretinografije (ERG) in vidnih evociranih potencialov (VEP) je mogoče ovrednotiti delovanje vidnega sistema od ravni retinalnega pigmentnega epitela, posa...
Article
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Purpose Assessment of multifocal ERG (mfERG) changes in patients treated with chloroquine and their correlation with morphological abnormalities, detected by spectral-domain optical coherence tomography in relation to cumulative dosage. Methods Data from 37 eyes of 20 patients were retrospectively collected, and one randomly selected eye per patie...
Article
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Purpose: To study electroretinograms in infantile nystagmus syndrome associated with idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism. Methods: A total of 30 children with idiopathic infantile nystagmus, 18 with optic nerve hypoplasia, and 18 with albinism were studied. Three electroretinogram protocols were applied according...
Article
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USH2A mutation is the most common cause of retinitis pigmentosa, with or without hearing impairment. Patients most commonly exhibit hyperautofluorescent ring on fundus autofluorescence imaging (FAF) and rod-cone dystrophy on electrophysiology. A detailed study of three USH2A patients with a rare pattern of double hyperautofluorescent rings was perf...
Article
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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 t...
Article
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To report clinical and electrophysiology findings in Slovene patients with Leber hereditary optic neuropathy (LHON). Eight patients with LHON (11-26 years; one female and seven males) were examined in acute stages and at follow-up visits by means of Snellen visual acuity, Ishihara color vision, Goldmann or Octopus G2TOP perimetry, fluorescein angio...
Article
To compare functional abnormalities of enhanced S-cone syndrome (ESCS), as examined using standard and extended electroretinography (ERG), with structural findings and retinal architecture obtained by spectral domain optical coherence tomography (SD-OCT). Four patients with ESCS underwent standard full-field and multifocal ERGs, with extended S-con...
Article
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Purpose: To differentiate early-onset retinal dystrophies on the basis of electroretinogram (ERG) characteristics in children with infantile nystagmus syndrome (INS). Methods: Thirty-seven children with INS and early-onset retinal dystrophies were included, with diagnosis according to clinical and ERG findings. Three ERG protocols were used acco...
Article
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Purpose: To evaluate intravitreal bevacizumab (IVB) treatment in patients with central retinal vein occlusion (CRVO) by spectral domain optical coherence tomography (OCT) and electroretinography (ERG). Methods: Twenty-two CRVO patients were treated with IVB injections and followed for 1 year. Morphological effect of treatment was observed with f...
Article
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The purpose of this study was to investigate chromatic visual evoked potential (cVEP) response characteristics during the first year of life and to collect as large database of healthy baby responses as possible. This study also complements our previous studies on cVEP in schoolchildren and preschool children. Forty-four healthy babies aged 3-12 mo...
Article
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The purpose of this study was to evaluate color vision in young patients with demyelinating disease both clinically and electrophysiologically. Thirty young patients (8–28 years, mean age 19 years) with demyelinating disease with or without a history of optic neuritis (ON) were investigated. Color vision was evaluated clinically with the Ishihara t...
Article
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Background and methods: In routine clinical evaluation of optic neuritis and chiasmal tumours, pattern electroretinography and visual evoked potentials (VEPs) to pattern-reversal stimulation are useful examinations. Similarly, in achiasmia and ocular albinism, VEPs to flash and pattern-onset stimulation provide relevant information. Results: The...
Conference Paper
Background / Purpose: Colour vison is often affected in people with demyelinating diseases (1). The goal was to test colour vision with standard colour vision tests and electrophysiologically with chromatic visual evoked potentials. Main conclusion: Significant difference was shown between the group without optic neuritis (nON) and the group w...
Article
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We present ophthalmic features and genetic analysis findings of a 44-year-old croatian patient with enhanced S-cone syndrome (ESCS). Complete ophthalmic examination, Ishihara colour vision test, dark adaptometry, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence imaging, Goldmann visual field and automated perimetry, fu...
Article
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Background: The aim of our study was to evaluate retinal function in children and young adults with Stargardt dystrophy by correlating retinal morphology (autofluorescence, OCT) with functional tests (visual acuity, microperimetry) and electroretinography (full-field ERG, pattern ERG, multifocal ERG). Patients and methods: 6 patients (3 F, 3 M, VA:...
Article
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Background: Electroretinography (ERG) enables assessment of the retinal function and facilitates the diagnostics of congenital nystagmus in children. The aim was to review the three categories of congenital nystagmus according to the clinical picture in relation to ERG findings: sensory, neurological and idiopathic nystagmus. Methods: This was a 5-...
Article
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Purpose: Congenital stationary night blindness (CSNB) is a group of retinal disorders with diverse clinical characteristics. The most common types are complete and incomplete CSNB. Both can have normal fundus appearance and an electronegative waveform of the electroretinogram (ERG). Our aim was to define ERG differences between complete and incompl...
Article
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Achiasmia is a rare disorder of visual pathway maldevelopment that can show diverse clinical and magnetic resonance imaging spectra. The aim of this study was to define the characteristics of visual evoked potentials (VEPs) that differentiate abnormal optic-nerve-fibre decussation in children with achiasmia versus children with albinism and healthy...
Article
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The purpose of the study was to analyze chromatic visual evoked potential (VEP) responses to isoluminant red–green (R–G) and blue–yellow (B–Y) stimuli in 30 preschool children (1.5–6 years). The predominant part of the response consisted of a positive (P) wave, which showed age-related latency changes (linear decrease). P wave latency was shorter w...
Article
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Izvleček Izhodišča: Elektroretinografija je preiskava, ki omogoča oceno delovanja mrežnice in tako pri-speva k diagnostiki prirojenega nistagmusa pri otrocih. Namen študije je bil opredeliti prirojeni nista-gmus pri otrocih po klinični sliki v povezavi z elektroretinogramom (ERG): kot senzorični, ne-vrološki in idiopatski nistagmus. Metode: V 5-let...
Article
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The aim of this study was to differentiate S-cone responses from other retinal activities using various recording conditions and to optimize these recording conditions for clinical diagnostics. S-cone responses to blue stimuli (449 nm) were studied in 20 healthy subjects and four patients with enhanced S-cone syndrome. The time-integrated luminance...
Article
Purpose To further investigate functional aspects of hyperautofluorescent ring, seen in retinal dystrophies. Methods Full ophthalmologic examination was performed, autofluorescence imaging was done by Heidelberg Engineering Spectralis/OCT, microperimetry with MP1 and electrophysiology. Results Hzperautofluorescent ring exhibited different character...
Article
Purpose To study chromatic and achromatic VEP responses in the first year of life. Methods In 30 babies aged 2 to 12 months VEP to chromatic and achromatic stimuli were binocularly recorded. Chromatic VEP were recorded to isoluminant red‐green and blue‐yellow stimulus. The stimulus was a circle composed of horizontal sinusoidal gratings with 90 % c...
Article
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Visual evoked potentials to chromatic stimulus (cVEP) are believed to selectively test the parvocellular visual pathway which is responsible for processing information about colour. The aim was to evaluate cVEP in children with red-green congenital colour vision deficiency. VEP responses of 15 colour deficient children were compared to 31 children...
Article
Purpose To report clinical and genetic characterization of two related patients with Leber hereditary optic neuropathy (LHON). Methods A 20‐year old man was referred in September 2004 for acute, painless and severe visual loss in his left eye, and then three weeks later in the other. Visual acuity (VA) on presentation was 0.2 in his right eye and H...
Article
Purpose In classification of sensory congenital nystagmus (CN) is important to recognize the underlying retinal or visual pathway dysfunction. The aim was to distinguish ERGs and VEPs charcteristics which may identify among variety of disorders associated with sensory CN. Methods In infants and small children that were ophthalmologically classified...
Article
Purpose Clinical challenge in diagnosis of optic neuropathies are atypical cases of either unknown visual loss or clinical cases in which the cause is identified, however, assessment of the visual function by psychophysical and morphological methods is not sufficiently accurate to assess the damage caused by lesion, or when functional follow‐up is...
Article
Patients who had had attacks of optic neuritis and whose VEPs showed ‘scotoma-tous’ waveforms in routine 0-16° r half-field testing, were examined in more detail with central (0-4° r) and peripheral (4-16° r) half-field stimulation in order to more reliably identify macularly (P100) and paramacularly (P135) derived components. It was found that thi...
Article
VEP abnormalities, radiologic CT findings and visual field defects are presented in 33 patients with compressive lesions of the optic chiasm. VEP abnormalities indicated either only dysfunction of crossed fibres or dysfunction of both the crossed and uncrossed fibres. Temporal and nasal visual field defects were consistent with VEP abnormalities ob...
Article
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The aim was to investigate the effects of monochromatic and broadband stimuli on the amplitude of the photopic negative response (PhNR) and to compare the sensitivities of these stimuli for the detection of ganglion cell damage in glaucoma patients. Forty-one healthy subjects were studied, along with 16 patients with open-angle glaucoma. Photopic e...
Article
Purpose The aim of our study was to evaluate retinal function in patients with genetically determined mutation in the ABCR gene by correlating retinal morphology with functional and electrophysiological tests. Methods 12 patients (10F, 2M, VA: 0,2±0,2) were included in the study. The central 10º visual fields were tested with Octopus M2 TOP and mic...
Article
Purpose To compare chromatic VEP response to isoluminant red‐green stimulus in children with congenital red‐green colour deficiency with a control group of 30 children with normal colour vision. Methods 15 children (7‐18 years) with congenital colour vision deficiency (8 in deutan and 7 in protan axis) and 30 healthy children (7‐19 years) were incl...
Article
Purpose To observe the S‐cone and LM‐cone responses of the photopic electroretinogram (ERG), to study their interactions, and to define under which stimulus conditions the ERG waveform reflect the function of the S‐cone as well as the L‐ and M‐cone systems. Methods The photopic ERG was recorded from 10 control subjects in a full‐field stimulator (D...
Article
Full-text available
The complete type of congenital stationary night blindness (complete CSNB) is a retinal disorder where the ON-response b-wave of the photopic electroretinogram is reduced, while the ON-response a-wave and OFF-response d-wave are preserved. These findings are related to ON-bipolar cell dysfunction, whereas the effects of myopia, which is usually ass...
Article
Visual processes continue to mature well into childhood, due to the development of the retina, optic nerve, visual pathway and visual cortex. Normal development of visual acuity and maturation of visual evoked potentials (VEPs) have been well studied, although rarely for their correlation. The purpose of this study was to investigate the same popul...
Article
Purpose: Electrophysiological methods enable exact layer by layer diagnosis of the retina and help to answer frequent diagnostic ambiguities between macular and optic nerve diseases. Methods: New multifocal techniques enable topographic representation of the retinal function and can provide accurate diagnosis of macular diseases in early stages. Cu...
Article
Purpose: To present clinical and histological features of lipofuscin autofluorescence of the retinal pigment epithelium‐RPE in a patient with cancer associated retinopathy‐CAR,a paraneoplastic syndrome caused by small cell lung carcinoma‐SCLC. Methods: 78 year‐old man with SCLC suffered bilateral blindness.Autofluorescence imaging was done using To...
Article
Purpose: To evaluate efficiency of recently developed genotyping microarray, the ABCR400‐chip, in combination with the denaturing high performance liquid chromatography (DHPLC) method sequencing to search for known ABCA4 mutations and to associate the findings with phenotype. Methods: 36 Slovenian patients with phenotype of STGD1 were analysed for...
Article
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Achiasmia is a rarely diagnosed visual pathway maldevelopment where all or the majority of nasal retinal fibres fail to decussate at the optic chiasm. It has been identified by neuroimaging and also by visual evoked potential (VEP) asymmetry. VEP asymmetry has not been defined consistently in previous studies. The aim was to study VEP asymmetry to...
Article
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Survey the actual clinical practice of pediatric visual electrophysiology. The electrophysiologists surveyed were members of the International Society for Clinical Electrophysiology of Vision (ISCEV). A self-administered questionnaire with 55 items about visual evoked potential (VEP) and electroretinogram (ERG) testing of pediatric patients was sen...
Article
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The aim of this study was to explore the effect of stimulus duration, stimulus intensity, stimulus wavelength and background luminance on the amplitude and waveform of the ON- (b-wave) and OFF- (d-wave) response of the photopic ERG. The following parameters were used in this study: stimulus duration from 5 to 200 ms, the flash intensities from 0.4...
Article
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The aim is to study chromatic visual evoked potentials (VEP) to isoluminant red-green (R-G) stimulus in schoolchildren. Sixty children (7-19 years) with normal color vision were examined, 30 binocularly and 30 monocularly. The isoluminant point was determined for each child subjectively by using heterochromatic flicker photometry, and objectively f...
Article
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Background. To describe diagnostic criteria, clini- cal manifestations and course of disease in patients with Mb. Vogt-Koyanagi-Harada (VKH), examined and treated at the University Eye Clinic in Ljubljana. Patients and methods. We included all patients diagnosed with VKH, who were treated at the University Eye Clinic in Ljublja- na. Their history,...
Article
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Elektrofiziološko vrednotenje vida pri otrocih omogoča odkrivanje nenormalnega razvoja vidnega sistema v fazi, ko je le dovolj plastičen, da secdajo nekatere napake povsem popraviti, druge pa vsaj zgodaj prepoznati ali zdraviti.
Article
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Two types of retinopathy are known to be assiociated with patients with malignancies: Cancer associated retinopathy-CAR and cutaneous melanoma associated retinopathy-MAR.
Article
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To study pattern-reversal visual evoked potentials (VEP) in patients with relapsing-remitting multiple sclerosis on interferon beta-1a treatment. In a randomized, prospective, non-blinded, placebo-uncontrolled study, VEP were studied in 9 patients (18 eyes) with relapsing-remitting multiple sclerosis treated with interferon. Three of them have had...
Article
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To determine the value of visual electrophysiological screening in evaluating retinal and postretinal visual pathway function in infants with congenital nystagmus. In 28 infants with congenital nystagmus electroretinogram (ERG) was recorded with skin electrodes and, since the infants were alert, visual evoked potentials (VEP) were simultaneously re...
Article
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Background. Studies have shown that chromatic information of visual stimulus is conducted and analysed in two major pathways, parvocellular (also named red-green pathway) and koniocellular (also named blue-yellow path- way). They both start in the retinal photoreceptors (cones) and finish in visual cortex. Colour vision can be tested in several dif...
Article
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Electrophysiological parameters in children reflect not only pathological processes, but also maturation of the visual system. This review investigates PERG and PVEP changes in infants and schoolchildren in order to establish the time scale for electrophysiological maturation of the visual system. Studies using pattern-reversal and pattern-onset st...
Article
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Optic neuritis (ON) in children usually presents with visual loss, relative afferent pupillary defect (RAPD), abnormal optic disc appearance, defects of visual field and colour vision, as well as with abnormalities of visual evoked potentials (VEP). Both, clinical and VEP parameters, improve after the attack; the time until recovery, however, is as...
Article
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The maturation of the visual system has been studied with pattern electroretinograms (PERG) and pattern visual evoked potentials (PVEP) mostly in children under the age of 6 years. To address the question of maturation of the visual system in childhood and adolescence we investigated age-dependent PERG and PVEP changes in children aged 7-18 years....
Article
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Background. This study was conducted to assess whether pattern ERG is a sensitive test in evaluating the reti- nal function in patients with retinitis pigmentosa. We wanted to determine how pattern ERG, reflecting the activity of inner retinal layers, is related to other psychophysical tests such as perimetry and visual acuity. Methods. An analysis...
Article
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The aim of the study was to asses the neurosensory retinal function in 12 patients (24 eyes) with different stages of Best's disease, by determining how pattern and full field flash ERG responses were related to visual acuity, stage of disease and extent of visual field loss. All patients had typically abnormal EOG responses and normal full field-f...
Article
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In 9 children (8-14 years of age) with orbital, suprasellar or postchiasmal tumours, visual loss was studied by visual electrophysiology in relation to ophthalmologic and neuroimaging findings. Pattern electroretinography (PERG) and pattern visual evoked potentials (PVEP) to full and half-field pattern-reversal stimulation were recorded and PERG an...
Article
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Our prospective clinical and electrophysiological study of children suspected of Leber's congenital amaurosis (LCA) was aimed to follow-up the course of their visual dysfunction. Electroretinography (ERG) and visual evoked potentials (VEP) to white flash stimulation were simultaneously recorded in 9 children at least twice. The first flash ERG and...
Conference Paper
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We studied visual evoked magnetic fields following pattern reversal stimulation of various portions of the visual field. The localisation of 100m dipoles superimposed on MRIs followed the retinotopic organisation of the striate cortex.
Conference Paper
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Optic neuritis is rarely confirmed in children, but often it is suspected. Considering that there are differences in the clinical features of ON in children we investigated the value of electrophysiology in uncertain ON cases. Therefore we compared PERG and VEP characteristics from children with suspected ON and definite ON to healthy children.
Article
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Visual evoked magnetic field (VEF) and visual evoked potentials (VEP) in response to pattern reversal left half-field central (0-2 degrees, 0-5 degrees) and to left half-field peripheral stimulation (2-15 degrees, 5-15 degrees) were simultaneously recorded in 10 normal subjects. The aim was to localize the origin of the largest wave around 100 ms....
Article
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To help clarify the conflicting evidence of neurophysiologic abnormalities in children with reading problems (dyslexia), we examined pattern electroretinograms and visual evoked potentials to stimulation with checks of 24', 49' and 180', each at 5%, 42% and 100% contrast, in a group of dyslexic children and a group of normal (i.e., normally reading...
Article
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In healthy subjects, the pattern visual evoked potential (VEP) arises predominantly from the stimulation of the central 5 degrees of the visual field. This central-field paradigm is well confirmed in VEP studies of retrochiasmal lesions, but it appears to be more ambiguous in patients with compressive lesions of the chiasm. To further clarify how c...
Article
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To address the question of a possible magnocellular visual deficit in children with reading problems (dyslexia), we examined pattern ERG and VEP responses to stimulation with checks of 24′, 49′ and 180′ in size and of 5%, 42% and 100% contrast level. Neurophysiological difference between children with reading problems and those without them was fou...
Article
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Recording of visual evoked potentials (VEPs) is not yet a routine test in patients with suspected chiasmal compressive lesions, but has proved useful to a clinician in assessing and following-up visual pathway dysfunctions. Abnormalities of VEPs can be found even in patients without clinical evidence of the visual impairment: VEP delays and alterat...
Article
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Selectivity and sensitivity of a visual electrophysiological test is closely associated with the possibility of proper physiological interpretation of the recorded potentials. The present paper discuss the importance of choosing anatomically and pysiologically relevant stimulus characteristics in ERG and VEP recordings. The examples are limited to...
Article
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Changes of the pattern reversal visual evoked potentials (VEPs) to half- and full-field stimulation in 50 patients with compressive lesions of the optic chiasm are presented. Temporal half-field stimulation yielded abnormal responses in 85% of the eyes, showing non-recordable P100 in 50% of eyes, while in 35% the P100 was significantly attenuated o...
Article
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Clinical findings and results of electrophysiologic evaluation of the visual pathway were studied in seven children ranging in age from 10 months to 13 years. Using skin electrodes for electroretinographic and visual evoked potential testing, we obtained reliable results without sedation or pupil dilation. The half-field stimulation was indispensab...
Article
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The site of a visual pathway lesion correlates with changes of the pattern reversal visual evoked potentials (VEPs). Optic nerve, optic chiasm and the retrochiasmal visual pathway lesions were explored by evoking visual potentials with a range of stimulus sizes (full-field, half-field and central-field). Multichannel recording of VEPs was used. It...
Article
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We studied W-shaped waveforms that occurred in full-field responses to pattern large-field stimulation in patients who had optic neuritis. Affected eyes showed no absolute scotomata; visual acuity was normal at the time of recording. To evaluate the contribution of macular- and paramacular-derived components to the development of the W-shaped wavef...
Article
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Pattern reversal visual evoked potentials (VEPs) were recorded from 38 patients with lesions affecting the chiasmal area. Lesions were confirmed by computer tomography and all patients had ophthalmologic examination. VEPs to full-field stimulation (0-16 degrees r) were compared with those obtained with half-field stimulation. Changes in VEPs were s...
Article
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Diagnostic value of transient pattern electroretinogram (PERG), recorded by skin electrodes, was compared with Goldmann perimetry in cases of ocular hypertension and glaucoma. According to the assumption that the PERG mostly reflects activity of the retinal glanglion cells, and histological evidence that 30–50% atrophy of the retinal ganglion cells...