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At least 19 recordsLinked to original sources

PubMed2003

Multifocal electroretinography in central serous chorio-retinopathy and assessment of the reproducibility of the multifocal electroretinography.

PURPOSE: To measure and compare the difference of multifocal electroretinography (mERG) in control subjects and patients with central serous chorio-retinopathy (CSCR) and assessing the reproducibility of the multifocal electroretinography. METHODS: Sixteen cases of control subjects and 12 cases of central serous chorio-retinopathy were tested with the Visual Evoked Response Imaging System science4.2 made by EDI company of America. The results of the left eye of each control subject and patient were used for statistical evaluation by the Mann-Whitney U test. Repeat measurements were performed on 11 control subjects. Wilcoxon technique were used to quantify the reproducibility of the test. RESULTS: The P1 waveform average response density of 1-3 rings in central serous chorio-retinopathy were decreased statistically. There was no significant difference between repeat measurements on 11 individuals. CONCLUSION: Multifocal electroretinography can be used to quantify the visual function of the affected area in chorio-retinopathy and showed good agreement in the data distribution for the repeat measurements.

Adult↗

PubMed2000

Electro-oculography, electroretinography, visual evoked potentials, and multifocal electroretinography in patients with vigabatrin-attributed visual field constriction.

PURPOSE: Symptomatic visual field constriction thought to be associated with vigabatrin has been reported. The current study investigated the visual fields and visual electrophysiology of eight patients with known vigabatrin-attributed visual field loss, three of whom were reported previously. Six of the patients were no longer receiving vigabatrin. METHODS: The central and peripheral fields were examined with the Humphrey Visual Field Analyzer. Full visual electrophysiology, including flash electroretinography (ERG), pattern electroretinography, multifocal ERG using the VERIS system, electro-oculography, and flash and pattern visual evoked potentials, was undertaken. RESULTS: Seven patients showed marked visual field constriction with some sparing of the temporal visual field. The eighth exhibited concentric constriction. Most electrophysiological responses were usually just within normal limits; two patients had subnormal Arden electro-oculography indices; and one patient showed an abnormally delayed photopic b wave. However, five patients showed delayed 30-Hz flicker b waves, and seven patients showed delayed oscillatory potentials. Multifocal ERG showed abnormalities that sometimes correlated with the visual field appearance and confirmed that the deficit occurs at the retinal level. CONCLUSION: Marked visual field constriction appears to be associated with vigabatrin therapy. The field defects and some electrophysiological abnormalities persist when vigabatrin therapy is withdrawn.

Adult↗

PubMed1995

A comparative study of intraocular irrigating solutions: effects on electroretinography readings during closed vitrectomy in humans.

The effects of intraocular irrigating solutions on electroretinography have been extensively studied in animal models, but effects on human electroretinography have not been reported. This study examined the effects of two commercially available irrigating solutions, S-MA2 (Opeguard MA) and DE-057 (BBS-Plus) on 30-Hz flicker electroretinography during closed vitrectomy in humans. Eight eyes of 8 patients were examined. All patients underwent a simple vitrectomy without treatment of proliferative membrane. For 30-Hz flicker electroretinography recording, a contact lens with a built-in light-emitting diode was sterilized and used as both a stimulus source and a recording electrode. Replacing S-MA2 with DE-057 decreased the electroretinography amplitude from 55.8 +/- 15.2 to 45.5 +/- 13.2 microV (mean +/- SEM). Changing the irrigation solution from DE-057 back to S-MA2 increased the amplitude from 45.5 +/- 13.2 to 59.9 +/- 17.3 microV. However, these changes were not statistically significant. Replacing S-MA2 with DE-057 significantly increased the peak time from 50.1 +/- 1.5 to 57.6 +/- 1.3 msec (p < 0.001). This change was reversible; after changing from DE-057 back to S-MA2, the peak time of flicker electroretinography significantly decreased from 57.6 +/- 1.3 to 49.0 +/- 2.1 msec (p < 0.01). Thus intraoperative 30-Hz electroretinography showed delayed peak time during irrigation with DE-057, as compared with S-MA2. The lower potassium concentration and higher glucose concentration of S-MA2, as compared with DE-057, may be the cause of such electroretinography changes.

Aged↗

PubMed2002

Multifocal electroretinography response after laser photocoagulation of a subretinal nematode.

PURPOSE: To describe multifocal electroretinography findings before and after laser photocoagulation of a subretinal nematode in diffuse unilateral subacute neuroretinitis. METHOD: Observational case report. A 45-year-old woman with left eye inflammation, subretinal tracts superior and temporal to the fovea, and a subretinal coiled mobile parasite was treated with laser photocoagulation to destroy the nematode. Multifocal electroretinography was performed before and after laser photocoagulation. RESULTS: In the left eye, multifocal electroretinography before treatment showed decreased foveal response density and increased parafoveal and perifoveal waveform amplitudes. Two months after laser photocoagulation, multifocal electroretinography showed full recovery of normal findings and the visual acuity remained 20/20. CONCLUSION: Multifocal electroretinography appears to be useful in evaluating the retinal findings after photocoagulation of a parasite associated with diffuse unilateral subacute neuroretinitis.

Electroretinography↗

PubMed2002

[Ganzfeld and multifocal electroretinography in Malattia Leventinese and Zermatt Macular Dystrophy].

BACKGROUND: To show the value of Ganzfeld electroretinography (ERG) in Malattia Leventinese (ML, or Hereditary Dominant Drusen) and Zermatt Macular Dystrophy (ZMD) and to illustrate multifocal electroretinography (mfERG) in 2 cases of ML. PATIENTS AND METHODS: In 15 patients with ML and 14 with ZMD we recorded Ganzfeld ERGs along with clinical examinations. In two patients with ML, and an we also performed a mfERG and an automated and Goldmann perimetry. All patients had a genotypic confirmation of the respective disease. For ERG measurements, the UTAS-3000 system was used, the mfERG was recorded using the RetiScan system. RESULTS: In ML, the visual acuity remained at 0.8 or higher until the 5 (th) or 6 (th) decade of life, followed by a rapid drop. In ZMD, the decrease in acuity began already in the 3 (rd) decade and followed a more continuous time course. The time course of the decrease of the ERG b-wave amplitudes was nearly identical for either disease. The mfERG showed in one case of ML a marked reduction in the macular response density but, in the second case, a normal density response pattern despite large degenerative changes at the posterior pole. In both of these patients, we found no visual field defects. CONCLUSIONS: Patient history and clinical testing raised the suspicion of a hereditary macular dystrophy. By means of Ganzfeld and multifocal electroretinography the course of the disease could be observed. However, definite diagnosis could only be established by genetic identification.

Adult↗

PubMed2001

Standardized electroretinography in primates: a non-invasive preclinical tool for predicting ocular side effects in humans.

This paper reviews the use of a standard protocol for electroretinography in drug safety evaluation studies with non-human primates. The architecture and physiology of the eye of humans and higher primates are very similar, thus making the non-human primate a preferred animal model for evaluating potential ocular side effects of drugs in humans. Using the technical and procedural features of the human protocol, i.e., the standard for clinical electroretinography (SCE), electroretinography can be routinely performed from early- to late-phases of drug development as a toxicodynamic endpoint for retinal toxicity and potential neurotoxicity in non-human primates. Hence, scientists can collect clinically relevant data using a standardized testing procedure found in the SCE. This is important in drug safety evaluations since the SCE is an established protocol that lends itself easily for incorporation into studies requiring adherence to international Good Laboratory Practice regulations. The technique is non-invasive, painless, and confers no adverse effects or damage to the eye.

Animals↗

PubMedDate not supplied

[Role of electroretinography in the prognosis of central retinal vein occlusion].

UNLABELLED: The aim of the study is to evaluate the role of electroretinography in diagnosis of central retinal vein occlusion CRVO. There are two forms of this entity, each of them having a different prognosis. While haemorrhagic form has a better outcome, with fairly good prognosis for vision, ischaemic form usually develops many complications: macular oedema, neovascularisation of the retina or optic disk, neovascular glaucoma, and possible blindness. Three months after the onset, when oedema and retinal haemorrhages are usually resolved, it is possible to perform fundus fluorescein angiography (FFA) and make differentiation between the two forms of the disease. However, neovascular glaucoma may challenge the vision even before the diagnosis of ischaemic form becomes possible by observing the fundus or by performing FFA. Trying to foresee the course of the disease, and thus to help a patient with panretinal photocoagulation, we performed electroretinography (ERG) in each patient just after the onset of the disease. The prospective study included 40 patients with CROV which lasted less than three months and without any complication. Two parameters were examined: scotopic "b" wave and photopic b/a ration. By ERG action potentials from the retina after its stimulation with light, are recorded. Scotopic "b" wave generates in bipolar layer from Muller's and bipolar cells. Photopic b/a ratio is a ration of two waves, "b" and "a" in photopic conditions and is a good indicator of saturation of the retina with blood and oxygen. Visual acuity, applanation tonometry, examination of the fundus after dilatation of pupils with Sol. Mydriacili were performed in each patient. Each patient was examined by ERG in scotopic and photopic conditions. The results were as follows: Scotopic b wave per se could not indicate potential complications, while b/a ratio was a good predictor of possible complications when its value was less than 1.25. CONCLUSION: Electroretinography, which can be performed at any time after the onset of the disease may be a good indicator of retinal perfusion and oxygen saturation, by giving the ratio of b and a waves under photopic conditions. The status of Muller's cells and bipolar cells is reflected in the scotopic b wave. In a prospective study forty patients with CRVO of less than three months duration and without neovascularisation were studied with the use of ERG, both in scotopic and photopic conditions. Our results suggest that the b/a ratio may be a good predictor of the development of retinal, disk and iris neovascularisation by showing the degree of retinal ischaemia, while the scotopic b wave cannot be used for such evaluation. Predicting the new vessel development by ERG may save the useful vision and prevent a disastrous outcome, blinding and painful neovascular glaucoma by performing panretinal photocoagulation.

Aged↗

PubMed1998

[Reproducibility and wave analysis of multifocal electroretinography].

We studied the reproducibility of multifocal electroretinography by repeated measurements in normal subjects. We also analyzed the amplitude and implicit time of the waves. Nine healthy eyes including myopic cases (-4.1 D on average) of 9 normal males, aged 19 to 42 years, were the objects of study. We used a (Visual Evoked Response Imaging System III (VERIS III), by TOMEY Corp.) for multifocal electroretinography. Each eye was examined 4 times on different days. The stimulus elements consisted of 103 hexagons. The net recording time was 4 minutes. We used the coefficient of variation (standard deviation/average) of 4 measurements of response density as index of reproducibility. Poor fixation and blinking were important factors that affected the reproducibility. In all the 9 eyes, reproducibility of multifocal electroretinography, expressed as average of the coefficient of variation of all regions, was 22% on average. In 6 eyes with good fixation and without blinking, the reproducibility was 15% on average. In 6 eyes with good reproducibility, we analyzed three parameters of the focal response waves: all traces, quadrants and rings, as well as the amplitude and latency of the waves. These data served as controls. Our studies showed that the response density correlated closely with the amplitude and not with the latency in normal subjects.

Adult↗

PubMedDate not supplied

Clinical applications of pattern electroretinography: melanoma, retinal detachment and glaucoma.

A comparison between results obtained by pattern electroretinography (ERG), Ganzfeld cone and rod-ERG was made in 7 patients suffering from melanoma, glaucoma and retinal detachment. It was shown that the extent of the lesions, not seen ophthalmoscopically, can be well monitored by the second harmonic component of pattern electroretinography in cases where conventional Ganzfeld ERG's do not reveal defects. Especially damage caused by acute glaucoma attacks and those stemming from chronic hypertension can be well differentiated.

Acute Disease↗

PubMed1978

Changes of the current pathways in the eye due to coating agents during electroretinography.

This study suggests a model by which we try to explain why coating agents habitually applied in electroretinography can change the amplitude of electroretinographic responses. The model is based on the results of experiments described in this paper. The accuracy of measurement in clinical and experimental electroretinography can be enhanced by applying this model.

Cellulose↗

PubMed2002

Evaluation of successful macular hole surgery by optical coherence tomography and multifocal electroretinography.

PURPOSE: To evaluate successful macular hole surgery using optical coherence tomography (OCT) and multifocal electroretinography (MFERG). DESIGN: Interventional case series. METHODS: In a prospective study, 20 eyes of 20 patients with successful surgery for stage II, III, or IV idiopathic macular hole were evaluated by best-corrected visual acuity (BCVA), ocular examination, OCT, and MFERG preoperatively and 1, 3, 6, and 12 months postoperatively. For statistical analysis, the paired t test and nonparametric methods were used, as well as the Spearman analysis. RESULTS: Postoperatively, all 20 eyes of 20 patients had anatomic closure of the macular hole confirmed by OCT. The center of the fovea, measured by OCT from the retinal pigment epithelium to the inner retinal surface, had a mean +/- SD thickness of 116.5 +/- 30.9 microm (range, 68-175 microm) 1 year postoperatively. Best-corrected visual acuity significantly improved (preoperative mean +/- standard deviation [SD] value, 0.131 +/- 0.081 and 1 year postoperative mean +/- SD value, 0.407 +/- 0.193). Multifocal electroretinography values area 1 (0-2.8 degrees) and area 2 (2.8-9 degrees from the center of the fovea) significantly improved (preoperative mean +/- SD values 3.10 +/- 1.334 nV/deg(2) and 3.573 +/- 1.545 nV/deg(2), respectively, and 1 year postoperative +/- SD mean values, 5.53 +/- 1.208 nV/deg(2) and 4.748 +/- 1.404 nV/deg(2), respectively). The thickness of the fovea, measured by OCT, significantly correlated with the BCVA 1 year postoperatively. One year postoperative MFERG values areas 1 and 2 were not correlated with 12-month BCVA and OCT findings. CONCLUSIONS: Twelve months postoperatively BCVA and MFERG values significantly improved in this series of eyes with successful macular hole surgery. Optical coherence tomography findings were correlated to BCVA, but MFERG values were not correlated to BCVA and OCT findings, 1 year postoperatively.

Aged↗

PubMed2000

Electroretinography is necessary for spasmus nutans diagnosis.

The purpose of the present study was to determine whether that which clinically appeared to be spasmus nutans could actually represent retinal sensory deficits diagnosable by electroretinography. Eight patients clinically thought to have spasmus nutans underwent electroretinography according to international standards. Five had normal electroretinograms and represented cases of true spasmus nutans. Three patients had abnormal electroretinograms, indicating that they did not have spasmus nutans. The clinical findings used to diagnose spasmus nutans can be simulated by retinal dystrophies. A normal electroretinogram is needed to confirm the diagnosis of spasmus nutans.

Case-Control Studies↗

PubMed1990

Electroretinography, retinal ischaemia and carotid artery disease.

Reduction in the amplitude of oscillatory potential (OP) on the B wave of an electroretinogram (ERG) is a sensitive index of experimental retinal ischaemia and is being used clinically to evaluate the progression of diabetic retinopathy. This study assessed whether electroretinography could detect retinal ischaemia in a group of patients with normal fluorescein angiograms and carotid atherosclerosis. Two groups of patients were studied. Group A (n = 15) had carotid atherosclerosis on duplex ultrasonography while a matched control group B (n = 15) had normal vessels. All patients in Group A had flurorescein angiograms. ERGs were recorded bilaterally using a Ganzfeld stimulator and Medelec oscilloscope. The OP amplitudes were determined using the peak-nadir method. Of the 60 eyes examined, 18 had abnormal OPs and all of these occurred in Group A; ten associated with ipsilateral non-stenosing carotid lesions and eight with critical stenoses. Twelve had normal OPs in Group A, only one of which was associated with severe disease. The mean OP amplitudes were 292 mu and 198 mu in Group A and 172.89 mu and 115.6 mu in Group B (P less than 0.005 Wilcoxon Rank Sum Test). (Two readings reflect Medelec readings before and after computer adjustments.) This study demonstrates by electroretinography significant retinal ischaemia in the presence of normal fluorescein angiography in patients with proven carotid artery disease. Further evaluation is required to determine the relative importance of flow reduction and silent micro-embolisation in the genesis of this ischaemia particularly in relation to pre- and postoperative evaluation.

Carotid Artery Diseases↗

PubMed2001

Detection of ophthalmoscopically occult maculopathy by focal electroretinography.

We performed focal electroretinography (FERG) in 10 patients with reduced vision of unknown cause. No patient gave a family history of uncorrectably reduced vision, and none had taken any drug known to damage the retina. Visual acuity claims ranged from 20/40 to finger counting. Color discrimination was reduced in all but one patient. Visual field sensitivity was reduced nonspecifically in five of the six patients who could perform perimetry reliably. Ophthalmoscopy showed no pertinent abnormality in four of 10 patients, mildly reduced foveal reflex in two of 10, arteriolar narrowing in two of 10, foveal pigment disturbance in one of 10, and preretinal gliosis in one of 10. Flash visual evoked potential (VEP) testing showed no abnormality in seven of 7 patients. The pattern VEP was reduced or delayed in five of 5 patients, only one of whom showed the expected amplitude loss with decreasing check size. Five patients completed full-field electroretinography, six patients completed fluorescein angiography, and none showed pertinent abnormality on either test. FERG was performed in both eyes of seven patients and in one eye of three others. Signals were non-recordable from four eyes, abnormal in nine, equivocal in three, and normal in one. The severity of FERG abnormality did not correlate with the severity of acuity loss. FERG abnormalities were found in fourteen of 17 eyes of 10 patients with vision loss out of proportion to clinical findings. In these patients only one of 5 pattern VEP tests, none of 5 full-field ERGs, and none of 7 fluorescein angiograms suggested correspondingly severe maculopathy. The FERG results in these cases mitigated suspicions of nonorganic vision loss and permitted speedier referral to retinal disease and low vision specialists.

Adolescent↗

PubMed1991

Electroretinography as a prognostic indicator or neovascularisation in CRVO.

A prospective study was carried out to compare the efficacy of electroretinography, fundus fluorescein angiography and clinical examination in identifying those at risk of rubeotic glaucoma following central retinal vein occlusion (CRVO). Our preliminary observations are described. The findings suggest a complementary role for electroretinography in the management of CRVO. Particularly significant were interocular differences in 30 Hz flicker latency, the ability to elicit pattern ERGs and the ratio of scotopic and photopic a:b wave amplitudes. Of the clinical measures the depth of the relative afferent pupil defect was a sensitive indicator of rubeosis. Factors of lesser statistical prognostic value included poor visual acuity and the extent of deep retinal haemorrhages. Fundus fluorescein angiography in this study had limited value in predicting those patients at risk of rubeosis.

Electroretinography↗

PubMed1993

[Clinical electroretinography: standard protocol and normal values].

The International Standard of Clinical Electroretinography serves as standard protocol for recording electroretinographic responses in order to facilitate worldwide comparisons of examinations. To promote its distribution and acceptance throughout the German speaking countries, we established normal values for the five standard responses and added a German translation of the International Standard in the appendix. To determine normal values for electroretinographic data we suggest to use percentiles instead of parameters based on a Gaussian distribution. Patient-related (age, sex) and -unrelated (interstimulus-interval, diurnal rhythm) parameters proved to influence the data values significantly. With these variables taken into account one can increase the clinical value of electroretinography in terms of a greater reliability and predictiveness of data.

Adolescent↗

PubMed2001

Multifocal electroretinography in multifocal choroiditis and the multiple evanescent white dot syndrome.

PURPOSE: To study and compare the findings on multifocal electroretinography (MERG) between multifocal choroiditis (MFC) and the multiple evanescent white dot syndrome (MEWDS). SUBJECT AND METHODS: Patients were recruited prospectively from the Department of Ophthalmology & Visual Sciences at the University of Iowa Hospitals & Clinics. They were evaluated using Goldmann visual fields (GVF) and MERG. Patients were diagnosed as having either MFC or MEWDS based on their clinical findings before MERG testing. RESULTS: Nineteen patients (23 eyes) were included in the study. Eleven patients were diagnosed with MFC and eight patients with MEWDS. Fourteen eyes with MFC and seven eyes with MEWDS were tested with MERG during the acute phase of their respective conditions. Fourteen patients (8 MFC and 6 MEWDS) were followed serially with MERG. Patients with MEWDS demonstrated focal depression corresponding to GVF defects with subsequent near total recovery of the MERG to baseline. Patients with MFC typically demonstrated diffuse loss of function over the entire test field. Focal scotomata, in addition to the diffuse depression, could be identified in 7 of 14 patients. Patients with MFC demonstrated only partial or no recovery of MERG following acute episodes, which was significantly different from the course followed by patients with MEWDS (P < 0.001, Fisher's exact test). CONCLUSION: Multifocal electroretinography differentiates MFC from MEWDS. Patients with MFC have permanent damage to the retina with diffuse depression of MERG. Patients with MEWDS, however, typically demonstrate greater focal loss initially on MERG followed by nearly full recovery of first order retinal function.

Acute Disease↗

PubMed1998

Multifocal electroretinography in patients with Stargardt's macular dystrophy.

AIMS: To describe the topography of multifocal electroretinograms (ERGs) and to explore its diagnostic value in patients with Stargardt's macular dystrophy (SMD). METHODS: 51 patients with SMD were examined by means of the m-sequence technique to characterise the topography of electroretinographic responses in the central visual field. The results were compared with data from 30 normal volunteers. RESULTS: In 49 of 51 patients with SMD, macular electroretinographic activity was markedly diminished or non-detectable. Towards more peripheral areas, ERG responses of the SMD patients approached those of normals. Implicit times were not markedly delayed at any eccentricity. CONCLUSION: In contrast with Ganzfeld electroretinography, multifocal electroretinography is useful to detect foveal dysfunction in SMD. Areas of dysfunction were found to be usually larger than expected from psychophysical measurements and morphological alteration. In early stages of the disease it was possible to detect foveal dysfunction, even in patients lacking morphological fundus changes and with good visual acuity.

Adolescent↗