• Klíčová slova
• ELECTRORETINOGRAPHY *, RECEPTORS, NEURAL *, VISION *,
• MeSH
• elektrofyziologické jevy * MeSH
• elektroretinografie * MeSH
• lidé MeSH
• nervové receptory * MeSH
• zrak * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: The DTL fibre electrode is commonly used to record the electric potentials elicited by stimulation of the retina. Two positions are commonly used: it is placed either on the cornea along the lower lid or in the conjunctival fornix. The PERG and OPs have previously been examined and compared under both conditions. The aim of this study was to examine the ERG, flicker response and on-off responses with differing electrode positions. METHODS: Before recruitment, all subjects underwent an ophthalmological examination. We enrolled 13 normal control subjects into the study aged 13-64 years, all with a visual acuity of ≥1.0. We recorded scotopic and photopic ERGs, flicker and on-off responses, for both electrode positions. On the first day, one eye had the electrode placed on the cornea along the lower lid and the other eye had it positioned in the conjunctival sac. On a second day, the recordings were repeated with the alternative electrode placements. RESULTS: ERG, on-off and flicker responses were all smaller by between 20 and 25% when the DTL electrode was positioned in the conjunctival sac, compared to when it was positioned on the cornea, as did the scatter in the data points. This indicates that there is no advantage clinically for one or the other placement. CONCLUSIONS: Our results confirm other reports examining the effect of electrode position on electrophysiological potentials. When recording with the DTL electrode, it is important to ensure that it is placed at the same position in repeat recordings or in multicentre trials and that it is stable and does not move during recording.

• Klíčová slova
• DTL electrode, Electrode position, Electroretinogram,
• MeSH
• dospělí MeSH
• elektrofyziologie metody   MeSH
• elektroretinografie metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mikroelektrody * MeSH
• mladiství MeSH
• mladý dospělý MeSH
• retina fyziologie   MeSH
• rohovka fyziologie   MeSH
• studie případů a kontrol MeSH
• světelná stimulace metody   MeSH
• zraková ostrost MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Intracardiac echocardiography (ICE) is the most practical method for online imaging during electrophysiological procedures. It allows guiding of complex catheter ablation procedures together with electroanatomical mapping systems, either with minimal or with zero fluoroscopy exposure. Besides safe and reproducible transseptal puncture, ICE helps to assess location and contact of the tip of the ablation catheter relative to specific anatomical structures. Another option is visualization of the arrhythmogenic substrate in patients with ventricular arrhythmias. This article describes the clinical utility of ICE in non-fluoroscopic electrophysiology procedures more in detail.

• Klíčová slova
• Electroanatomic mapping, Electrophysiology procedures, Fluoroscopy, Intracardiac echocardiography,
• MeSH
• chirurgie s pomocí počítače metody   MeSH
• echokardiografie metody   MeSH
• elektrofyziologické techniky kardiologické metody   MeSH
• fluoroskopie MeSH
• katetrizační ablace metody   MeSH
• lidé MeSH
• srdce diagnostické zobrazování   MeSH
• srdeční arytmie diagnostické zobrazování   chirurgie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

• Klíčová slova
• BRAIN ELECTROPHYSIOLOGY *, ELECTRORETINOGRAPHY *, INFANT, NEWBORN *, INFANT, PREMATURE *, VISION *,
• MeSH
• elektrofyziologické jevy * MeSH
• elektrofyziologie * MeSH
• elektroretinografie * MeSH
• kojenec MeSH
• lidé MeSH
• mozek fyziologie   MeSH
• novorozenec nedonošený * MeSH
• novorozenec MeSH
• zrak * MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• novorozenec MeSH
• Publikační typ
• časopisecké články MeSH

Reports of visual functional impairment in spinocerebellar ataxia type 2 (SCA2) have been studied previously using pattern reversal visually evoked potentials (VEPs) with contradictory results. To provide additional evidence to this area, visual functions were studied using VEPs and event-related potentials (ERPs) in a group of ten patients with genetically verified SCA2. The electrophysiological examination included pattern reversal and motion-onset VEPs as well as visually driven oddball ERPs with an evaluation of a target and a pre-attentive response. In six patients, we found abnormal visual/cognitive processing that differed from normal values in latency, but not in the amplitude of the dominant VEP/ERP peaks. Among the VEPs/ERPs used, the motion-onset VEPs exhibited the highest sensitivity and showed a strong Spearman correlation to SCA2 duration (from r = 0.82 to r = 0.90, p < 0.001) and clinical state assessed by Brief Ataxia Rating Scale (from r = 0.71 (p = 0.022) to r = 0.80 (p < 0.001)). None of the VEP/ERP latencies showed a correlation to the triplet repeats of the SCA2 gene. In three patients, we did not find any visual/cognitive pathology, and one subject showed only a single subtle prolongation of the VEP peak. The observed visual/cognitive deficit was related to the subjects' clinical state and the illness duration, but no relationship to the genetic marker of SCA2 was found. From the VEP/ERP types used, the motion-onset VEPs seems to be the most promising candidate for clinical state monitoring rather than a tool for early diagnostic use.

• MeSH
• DNA genetika   MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• elektrofyziologické jevy MeSH
• evokované potenciály fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• neurologické vyšetření MeSH
• počítačové zpracování signálu MeSH
• rozpoznávání obrazu fyziologie   MeSH
• senioři MeSH
• spinocerebelární ataxie genetika   patofyziologie   psychologie   MeSH
• stárnutí fyziologie   MeSH
• světelná stimulace MeSH
• trinukleotidové repetice MeSH
• věk při počátku nemoci MeSH
• zraková percepce fyziologie   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• zrakové korové centrum patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA MeSH

• MeSH
• akustická stimulace MeSH
• elektrofyziologie MeSH
• evokované potenciály MeSH
• králíci MeSH
• světelná stimulace MeSH
• zrakové korové centrum fyziologie   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: Several methods are routinely used in the clinic to diagnose and monitor diseases of inner retinal function. In this study, we compare four such methods in patients with diabetes and glaucoma, to determine correlations between their results and to determine which method is most sensitive for detecting disease. METHODS: Twenty control subjects, 12 patients with early glaucoma and eight patients with diabetes mellitus, were enrolled in the study. All underwent four examinations: transient pattern electroretinogram (PERG), multifocal pattern electroretinogram (mfPERG), chromatic contrast threshold measurements (protan and tritan), and blue-on-yellow short-wavelength automated perimetry (SWAP). RESULTS: For the total cohort of 40 subjects, the results show a significant correlation between the amplitudes of the PERG and those of the mfPERG, as well as between the tritan contrast thresholds and the SWAP MD. Furthermore, ROC analyses reveal that colour contrast thresholds could significantly distinguish between the patient and the control group. Glaucoma patients alone could also be distinguished. CONCLUSIONS: We conclude that the methods compared in this study show correlations between their results if they are testing same pathway or underling cells, and that the colour contrast threshold is the most sensitive method to detect early functional deficits in diabetic and glaucoma patients.

• Klíčová slova
• Diabetes, Diagnostic tests, Electroretinography, Glaucoma, Psychophysics, Retina,
• MeSH
• čípky retiny fyziologie   MeSH
• citlivost na kontrast fyziologie   MeSH
• diabetes mellitus 1. typu diagnóza   patofyziologie   MeSH
• diabetická retinopatie diagnóza   patofyziologie   MeSH
• dospělí MeSH
• elektrofyziologické jevy MeSH
• elektrofyziologie metody   MeSH
• elektroretinografie metody   MeSH
• glaukom diagnóza   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• poruchy barevného vidění diagnóza   patofyziologie   MeSH
• ROC křivka MeSH
• senioři MeSH
• senzorické prahy MeSH
• testy zrakového pole MeSH
• zraková pole fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

• Klíčová slova
• BRAIN ELECTROPHYSIOLOGY *, CEREBRAL CORTEX *, LIGHT *, REVIEW *, VISION *,
• MeSH
• mozek fyziologie   MeSH
• mozková kůra * MeSH
• světlo * MeSH
• zrak * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Hypertensive glaucoma is defined as a group of diseases with progressive loss of the neuroretinal margin of the optic disc that causes characteristic degenerative optic neuropathy. The present study provided an updated summary of the physiology and pathology of neurotransmission in the visual path, with the focus on glaucoma. The results of positron emission tomography, functional magnetic resonance imaging and mainly electrophysiological methods demonstrated pathogenesis of nerve cell damage in the visual pathway. Based on these conclusions, neuroprotection in glaucoma was proposed. This consists mainly of the reduction of the intraocular pressure. It is followed by a decrease of glutamate in the synaptic cleft and blockade of its binding to the NMDA receptors. The supply of energy substrates to altered nerve cells is also indispensable. Therapy should be systemic due to impairment of the complete visual path.

• Klíčová slova
• glaucoma, neuroprotection, physiology and pathology of transfer in the visual path,
• Publikační typ
• časopisecké články MeSH

PURPOSE: The aim of this study was to develop a simple and reliable method for the objective assessment of visual acuity by optimizing the stimulus used in commercially available systems and by improving the methods of evaluation using a nonlinear function, the modified Ricker model. METHODS: Subjective visual acuity in the normal subjects was measured with Snellen targets, best-corrected, and in some cases also uncorrected and with plus lenses (+ 1 D, + 2 D, + 3 D). In patients, subjective visual acuity was measured best-corrected using the Freiburg Visual Acuity Test. Sweep VEP recordings to 11 spatial frequencies, with check sizes in logarithmically equidistant steps (0.6, 0.9, 1.4, 2.1, 3.3, 4.9, 7.3, 10.4, 18.2, 24.4, and 36.5 cpd), were obtained from 56 healthy subjects aged between 17 and 69 years (mean 42.5 ± 15.3 SD years) and 20 patients with diseases of the lens (n = 6), retina (n = 8) or optic nerve (n = 6). The results were fit by a multiple linear regression (2nd-order polynomial) or a nonlinear regression (modified Ricker model) and parameters compared (limiting spatial frequency (sflimiting) and the spatial frequency of the vertex (sfvertex) of the parabola for the 2nd-order polynomial fitting, and the maximal spatial frequency (sfmax), and the spatial frequency where the amplitude is 2 dB higher than the level of noise (sfthreshold) for the modified Ricker model. RESULTS: Recording with 11 spatial frequencies allows a more accurate determination of acuities above 1.0 logMAR. Tuning curves fitted to the results show that compared to the normal 2nd-order polynomial analysis, the modified Ricker model is able to describe closely the amplitudes of the sweep VEP in relation to the spatial frequencies of the presented checkerboards. In patients with a visual acuity better than about 0.5 (decimal), the predicted acuities based on the different parameters show a good match of the predicted visual acuities based on the models established in healthy volunteers to the subjective visual acuities. However, for lower visual acuities, both models tend to overestimate the visual acuity (up to ~ 0.4 logMAR), especially in patients suffering from AMD. CONCLUSIONS: Both models, the 2nd-order polynomial and the modified Ricker model performed equally well in the prediction of the visual acuity based on the amplitudes recorded using the sweep VEP. However, the modified Ricker model does not require the exclusion of data points from the fit, as necessary when fitting the 2nd-order polynomial model making it more reliable and robust against outliers, and, in addition, provides a measure for the noise of the recorded results.

• Klíčová slova
• Sweep VEP, Visual acuity, Visual electrophysiology, Visual evoked potentials,
• MeSH
• dospělí MeSH
• elektroretinografie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nemoci oční čočky patofyziologie   MeSH
• nemoci retiny patofyziologie   MeSH
• nemoci zrakového nervu patofyziologie   MeSH
• senioři MeSH
• statistické modely MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• zraková ostrost fyziologie   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• zrakové testy metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH