PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ELECTRORETINOGRAPHY”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

[Modern electroretinography].

The paper describes the current types of electroretinography, the origin of electric retinal activity and its role in the diagnosis, differential diagnosis, and monitoring of retinal diseases of various origin. It presents the electroretinographic symptoms typical of pathology of the retinal cone and rod system in some hereditary diseases whose genes have been mapped and cloned to date and whose pathogenesis specified. The current concepts of retinal remodeling in its dystrophic changes are produced and emphasis is laid on the necessity of using the progress of vision biology and physiology in ophthalmological practice.

Diagnosis, Differential↗
PubMed1991

Flash visual-evoked potentials and flash electroretinography in the preoperative visual prognosis of eyes with cataracts.

This study evaluated the reliability of flash visual-evoked potentials and flash electroretinography in the prognosis of postoperative visual acuity after cataract extraction. We tested 94 patients with cataract in whom the preoperative visual acuity ranged from light perception to 3/10. On the basis of the electrophysiologic tests, we formulated three types of preoperative visual prognosis: high, intermediate, and poor. To assess the postoperative visual acuity, all subjects were followed for at least three months after cataract extraction. Visual acuity was subdivided in three arbitrary classes: less than or equal to 1/10, between 2/10 and 5/10, and between 6/10 and 10/10. Finally, we evaluated the reliability of our preoperative prognosis. Statistical analysis of our results (using the chi-square test) showed our predictions were highly significant for the total sample, revealing a strict correlation between our prognosis and the final visual acuity.

Adult↗
PubMed1991

[Clinical electroretinography in the dog. Part 2].

The second part of this study deals primarily with the technical aspects of electroretinography. A custom made dark chamber for the patient is presented. The requirements for an optical stimulator are discussed in detail and the recording instrumentation--electrodes, amplifiers, averager, digitalizer--are presented. The display of the signals on a monitor and plotter concludes this technical description. The remainder of part 2 is devoted to the many factors influencing the recording of an ERG, notably pupillary diameter, anesthesia, oxygen and glucose supply to the animal, body temperature of the patient, its intraocular pressure and level of retinal adaptation, and finally the age of the patient. On the technical side the intensity, wavelength and frequency of stimulation play an important role.

Animals↗
PubMedDate not supplied

[Assessment of retinal function in cataract by electroretinography].

Electroretinography (ERG) was used to assess the functions of the retinal central and peripheral sections in patients with cataracts of various origins and different degrees of opacities; the method is based on the use of 18-20 degrees red saturating stimulus fit in sucker electrode for macular ERG and Hanz-Feld white stimulus for total ERG. Macular biopotential recorded in the patients with mature cataracts without pathologic changes in the macular region coincided with the mean values of local macular ERG recorded in transparent ocular media with medium-intensity stimuli. Macular biopotentials in cataracts significantly differed from the normal values in dystrophic changes of the macular area. Total ERG values in transparent ocular media and in mature cataract patients coincided only in with saturating white stimulus in cases when no retinal abnormalities were present. ERG with weak and medium-intensity stimulating light has shown has shown a significant difference of ERG parameters in these patient populations. Analysis of ERG findings in 375 patients with cataracts of various origins and with various opacity degrees has shown the possibility of extrapolating the data on ERG symptoms of retinal abnormalities known in transparent ocular media to the diagnosis of the pathologic processes in the retina when the fundus of the eye cannot be seen; this method will be useful in predicting visual functions in the postoperative period.

Adolescent↗
PubMed1987

Contribution of electroretinography to diagnosis of color vision deficiencies.

The role that electroretinography (ERG) has played in the past and might play in the future in the study of color vision deficiencies is discussed in this paper. First, an example is given of how Copenhaver and Gunkel concluded in 1958 the absence of the green cone system in deuteranopia before Rushton, with the more direct method of densitometry, reached the same conclusion. Padmos and van Norren showed in 1971 that chromatic adaptation did not change a dichromat's spectral sensitivity curve, which fits the model of a loss system. A comparison between dichromats' spectral sensitivity curves based on the rapid off-response and recent data on single monkey receptors showed a slight but systematic discrepancy, indicative of a rod contribution in the off-response method. Carriers of color vision deficiencies might be more readily detected with an ERG than with a psychophysical method. The early receptor potential (ERP) seems a less suitable means to study color vision deficiencies. The blue cones form an interesting subject of study since they seem to be the most vulnerable cone type. With an ERG method a localization of acquired tritan deficiencies is possible. A recent finding is that blue cones are substantially more sensitive to light damage than either rods, or red or green cones.

Color Vision Defects↗
PubMed1987

Spectral characteristics of electroretinography in congenital red-green color blindness.

There are few conclusive electroretinography (ERG) studies comparing the spectral characteristics in deutans and normals in contrast to protans and normals. The difficulties of research on deutans were thought to be due to problems in detecting the very slight differences in the spectral characteristics between deutans and normal subjects. To record monochromatic ERG responses accurately in deutans, our time-locked scanning method was improved as follows: We used 12 interference filters for stimulus lights with narrow half widths (4-6 nm) and wavelengths of peak transmission arranged at intervals of 10 nm between 520 nm and 600 nm. Each stimulus light was strictly adjusted to an equal energy and checked simultaneously with ERG recordings. Contact lens electrodes were reformed for comfortable fitting to subjects' corneas. The time interval between each stimulation was set at 300 msec and one scanning of all stimulations took only 3.9 sec. ERG bp-waves were recorded in congenital color blindness by scanning monochromatic light stimuli, and spectral responses obtained could be evaluated as a spectral pattern. Different spectral patterns of responses from those of normal subjects and shift of the peak in the spectral response curves were obtained for congenital color blind subjects. The maximal responses were recorded at around 540 nm in protans and at 570-580 nm in deutans under white adaptation. Differences in the response curves were not found between dichromats and anomalous trichromats. Moreover, selective chromatic adaptation disclosed the separate responses of green cone and red cone systems. In normal subjects the peak of the spectral response curves was shifted to around 540 nm by red adaptation and to around 580 nm by blue adaptation. The spectral patterns changed so that they looked like the patterns under white adaptation of protans and deutans, respectively. But in protans and deutans the same spectral response patterns and almost the same wavelengths of the peak in the spectral response curves as those obtained under white adaptation were recorded under chromatic adaptation. This method provides the possibility of differentiating between red and green color blind subjects and normal subjects by the ERG. Defects or marked abnormality in the red cone system in protans and the green cone system in deutans can also be detected. Monochromatic ERGs of deutans were recorded under more intense red adaptation.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1986

[Pigmentary retinopathy of neonates and infants. Their examination using electroretinography and visual evoked potentials].

A method of neurophysiological investigation (electroretinography and visual evoked potentials) is described as a non invasive exploration used in awake children. E.R.G. and V.E.P. normal patterns are described in relation to age. The data obtained in pigmentary retinopathies are referred to the physiopathology of these diseases. Usefulness of both neurophysiological tests is showed in the early diagnosis. Significative abnormalities are seen even before any detectable ophthalmoscopic symptom. In pigmentary retinopathies, V.E.P. are normal while E.R.G. is slightly then severely altered. E.R.G. and V.E.P. are also helpful in the differential diagnosis: in macular diseases, E.R.G. is usually normal while V.E.P. are altered. Repeated examinations have a prognostical value: when a disease is progressing, E.R.G. becomes more and more altered and V.E.P.'s abnormalities appear.

Electroretinography↗
PubMed1987

An improved method for using the DTL fibre in electroretinography.

An improved method using DTL fibre for electroretinography is described. The DTL fibre is comfortable and easy to apply. Corneal anaesthesia is unnecessary. The DTL fiber does not interfere with the retinal image and has been used successfully to record both pattern and flash electroretinograms from subjects of all ages.

Electrodes↗
PubMed1979

Improved electrode for electroretinography.

Corneal electrodes useful for clinical electroretinography require topical anesthesia, interfere with vision, can abrade, and are not well accepted by most children and many adults. A low mass conductive thread, corneal (DTL) electrode is described and comparatively tested against the Burian-Allen electrode. The DTL electrode was found to have few of the limitations of the hard contact lens electrode. Furthermore, the DTL electrode signal quality was comparable to that of the Burian-Allen electrode and provided less between-patient variability.

Adult↗
PubMedDate not supplied

Electroretinography and diagnosis of the Laurence-Moon-Bardet-Biedl syndrome in childhood.

The cases of two children affected from LMBB syndrome are reported. The first child was six years old, suffering from obesity and mild mental retardation; the other was two years old, suffering from hexadactyly and obesity. In both children the suspected diagnosis of LMBB syndrome was verified by the electroetinographic evidence of a tapetoretinal degeneration although the fundi were atypical. A third child, the younger brother of the second case, presented an atypical pigmentation of the retina and the electroretinographic changes of a tapeto-retinal degeneration. Since tapeto-retinal degeneration, which is the most common of the main signs of the syndrome, is not always recognized by ophthalmoscopy in early childhood, the clinical value of electroretinography in making an early diagnosis is emphasized.

Adult↗
PubMed1984

Maturation of the retina of the canine neonate as determined by electroretinography and histology.

Retinal potentials were obtained by electroretinography from birth to maturity of dogs. Amplitudes, time latency, and flicker fusion frequencies under scotopic conditions were compared to the histologic development of the retina. There was no electroretinogram (ERG) recorded during the 1st week of life, but in the 2nd week, a small negative wave (not exceeding 5 microV) was detected. Small ERG waveforms appeared in dogs at 3 weeks of age; these markedly increased in amplitude and latency between the 3rd and the 4th weeks of age. Additional changes in the ERG amplitudes were evident in the 5th to the 8th weeks of life approximating amplitudes of the adult dog. Similarly, the greatest changes in flicker fusion frequencies occurred between the 3rd and the 5th weeks and the 7th and the 8th weeks. Latency of the a-wave indicated little change in the age groups studied. The greatest decrease in latency occurred in the b- and c-waves between the 3rd and 5th weeks of age. The rod and cone inner and outer segments were first observed microscopically in the 3rd week after the dogs were born. Further differentiation of the rod and cone segments and other retinal layers occurred from the 5th to the 8th weeks.

Aging↗
PubMed1982

Electroretinography and visual evoked responses in paediatric practice.

Electroretinography an the recording of visual evoked responses are of considerable value as ancillary investigations in clinical ophthalmology, paediatric neurology an developmental paediatrics. The techniques used are non-invasive and yield objective results without any need for patient co-operation. In this study 159 children were examined using a system constructed from apparatus available in South Africa. Indications for the investigations included developmental delay, acute intracranial disease, eye disease and cerebral degenerative disorders. Information obtained made possible distinctions between retinal dysfunction and lesions of optic pathways, the occipital cortex and higher cortical centres.

Adolescent↗
PubMed1980

[The therapy with synthetic antimalarial drugs controlled by fluorescence electroretinography (author's transl)].

Chloroquine retinopathy is a drug disease that can be prevented. Among some suggested methods, fluorescence electroretinography allows an evaluation of drug retinal deposit. In fact if a fluorescent substance accumulates in the retinal cells, a very short wavelength stimulus can produce a bioelectric response. If soon detected drug absorption is reversible. Only in a long run, the drug can induce irreversible damages. Thus the importance of continuous control of the patients in treatment with chloroquine-drugs is necessary. In this study the results of an investigation of 38 patients treated with synthetic anit-malarial drugs are shown. In some subjects the presence of the drug in the retina, without anatomic lesions, was demonstrated. These deposits disappeared upon cessation of the treatment. Deposits with or without retinal lesions were noticed in 31% of the observed subjects. In these patients the suspension of drug administration reduced accumulation but did not influence retinal lesion shown by fluorangiography. The authors hypothesized that fluorescent substance deposit is made easier by retinal vasculopathy due to connective tissue disorders.

Chloroquine↗
PubMed1978

Ketamine hydrochloride: an effective general anesthetic for use in electroretinography.

Ketamine hydrochloride, a relatively safe general anesthetic agent, has been demonstrated to be effective for use in electroretinography. Pigmented rabbits were given a dose of 25 mg/kg intravenously. The oscillatory potentials in light and dark adapted states and the ERG under various light adapted states after ketamine administration were not significantly different from baseline values.

Action Potentials↗
PubMed1993

Diagnostic evaluation of diabetic retinopathy by 30-Hz flicker electroretinography.

The peak latency in 30-Hz flicker electroretinography (ERG) was determined in patients with diabetic retinopathy, using a newly developed contact lens electrode with built-in light-emitting diode. A good correlation was obtained between the peak latency of flicker ERG and that of oscillatory potentials of flash ERG. The peak latency of the flicker ERG was only slightly prolonged in background retinopathy, but markedly prolonged in proliferative retinopathy. The stage of pre-proliferative retinopathy with normal peak latency in flicker ERG may be a compensatory state of the retina, which is the most appropriate stage for laser treatment of diabetic retinopathy.

Adult↗
PubMed1997

Extra-muscle involvement in dystrophinopathies: an electroretinography and evoked potential study.

Dystrophin is present in various tissues other than skeletal and cardiac muscles, including the central nervous system (CNS) and the outer plexiform layer of the retina. Therefore lack of dystrophin might be related to mental retardation or to changes in electrophysiological tests exploring retina and CNS. We performed electroretinography, VEPs, BAEPs, SEPs and MEPs in 18 patients with Duchenne muscular dystrophy (DMD), 18 with Becker muscular dystrophy (BMD) and 12 obligate carriers. We observed a marked reduction of the b-wave amplitude in the scotopic ERG, mainly in DMD patients. Oscillatory potentials were altered in all groups, even in carriers, suggesting that dystrophin may be also involved in retinal circulation. VEPs changes confirmed the role of dystrophin in visual function. The other evoked potentials were altered only in a small percentage of subjects but changes of different tests did not overlap in individual subjects. Neurophysiological abnormalities did not correlate with type, site and size of alteration in the dystrophin gene.

Adolescent↗
PubMed1993

[Diagnostic electroretinography in the young child].

As soon as visual impairment is suspected in a newborn or an infant by an ophthalmologist or pediatrician, it becomes important to document retinal function. Electroretinography (ERG) in general anesthesia as an outpatient procedure allows to assess the functional state of the retina. In addition, we make use of the anesthesia for ophthalmoscopopy, photography, slit lamp examination and occasionally tonometry. Within the first 10 min of dark adaptation we can electroretinographically distinguish between rod- and cone-mediated b-waves. Anesthesia is performed with Ketamine, occasionally supplemented with Halothane and additional oxygen under noninvasive monitoring of the oxygen saturation. The expenditure of a pediatric check-up and general anesthesia is in our view justified in the light of the opportunity to assess or to exclude a degenerative retinal disease early on. In Leber's congenital amaurosis, a disorder accounting for about 3.5% of blindness in infants, the ERG result is essential, particularly when ophthalmoscopic changes are missing. The prevailing diagnoses in our cases include, in decreasing frequency, congenital cataract, ROP, tapetoretinal degenerations, pediatric-neurologic syndromes, and microphthalmus.

Anesthesia, General↗