Search results for "Retinography"
showing 10 items of 59 documents
Retinal neurodegenerative changes in the adult insulin receptor substrate-2 deficient mouse.
2014
Abstract Insulin receptor substrate-2 (Irs2) mediates peripheral insulin action and is essential for retinal health. Previous investigations have reported severe photoreceptor degeneration and abnormal visual function in Irs2-deficient mice. However, molecular changes in the Irs2 − / − mouse retina have not been described. In this study, we examined retinal degenerative changes in neuronal and glial cells of adult (9- and 12-week old) Irs2 − / − mice by immunohistochemistry. 9-week old Irs2 − / − mice showed significant thinning of outer retinal layers, concomitant to Muller and microglial cell activation. Photoreceptor cells displayed different signs of degeneration, such as outer/inner…
Retinal Sensibility to Drugs in Normal Rats and Carriers of Inherited Retinal Degeneration
1972
Secondary retinitis pigmentosa of pseudo-retinitis pigmentosa can be brought about by certain diseases, especially exanthematic or viral ones.
ERG signal analysis using wavelet transform
2009
The wavelet analysis is a powerful tool for analyzing and detecting features of signals characterized by time-dependent statistical properties, as biomedical signals. The identification and the analysis of the components of these signals in the time-frequency domain, give meaningful information about the physiological mechanisms that govern them. This article presents the results of the wavelet analysis applied to the a-wave component of the human electroretinogram. In order to deepen and improve our knowledge about the behavior of the early photoreceptoral response, including the possible activation of interactions and correlations among the photoreceptors, we have detected and identified …
Electroretinographic oscillatory potentials in insulin-dependent diabetes patients: A long-term follow-up.
2002
Purpose: The aim of this research was to study the relevance of long-term follow-up of electroretinographic oscillatory potentials (OPs) in predicting the onset of minimal non-proliferative diabetic retinopathy in insulin-dependent diabetes patients. Methods: A total of 80 insulin-dependent diabetics, with normal fundi and normal OPs at first examination, were followed prospectively for 10 years. Oscillatory potentials were measured and fundus examinations performed once or twice per year. Results: During follow-up, 35% of patients developed diabetic retinopathy after a mean disease duration of 12 ± 2 years. A decrease in OP amplitudes was seen in 46% of this group, but reductions were also…
Time course of IOP elevation, electroretinographic changes and retinal ganglion cell loss in a rat model of glaucoma induced by laser
2007
International audience; Purpose: To evaluate the time course of intraocular pressure (IOP) elevation, electroretinographic changes and retinal ganglion cell (RGC) loss in a rat model of glaucoma induced by photocoagulation of the trabeculum and the episcleral and limbal veins. Methods: Male Sprague Dawley rats were used at 6 weeks of age. At least 3 of the episcleral veins, the trabeculum and the limbal veins were photocoagulated with a laser at 532nm (Quantel Medical, Vitra) in one eye of the animals. IOP and electroretinogram (ERG) were monitored every 2 weeks during 11 weeks after photocoagulation. Three months after laser photocoagulation, the RGC population was identified with a 5% Flu…
Effect of intravitreal injection of Indocyanine Green, Triamcinolone Acetonide and Trypan Blue on the electroretinographic response of rats
2007
International audience; Purpose:: Indocyanine Green (ICG) and Tripan Blue (TB) are commonly used in macular surgery by making easier the internal limiting membrane (ILM) removing. However, the innocuousness of these dyes is not actually established notably for ICG. Then, several authors proposed the use of triamcinolone acetonide (TA) as an alternative to the use of intraoperative dyes for visualizing the ILM. The purpose of this study was to evaluate the effects of intravitreal injection of ICG, TB and TA on the rat electroretinogram (ERG). Methods:: Three groups of 12-week-old Sprague Dawley rats (n=6) received intravitreal injection in one eye of 0.1mL of either ICG 0.5mg/mL, TB 3mg/mL o…
Electroretinography in newborn and young infants without sedation
2009
International audience; Purpose: Electroretinography (ERG) is frequently a relevant diagnostic test in pediatric ophthalmology and neurology. ERG at early age is not easy to perform and requires simplified recording protocols and specific norms. In our laboratory especially devoted to developmental studies, an ERG recording method has been adapted to the very young infant. Methods: Monocular ERG was performed in 60 healthy subjects from birth at term to 3 years of age. ERG was recorded using disposable contact lens electrodes in the conscious child with eyes open, after topical anesthesia but without sedation. Stimulus was a white flash (color temperature 5600°K, energy at source 0.3J) appl…
Electrofunctional features of the tilted disc syndrome.
1986
The ERG, EOG and VEPs of 15 patients with tilted disc syndrome were studied. The ERG showed abnormal amplitudes in about 1/4 of the eyes and the EOG values were pathological in 3 patients. It is probable that the abnormality of the inferior-nasal portion of the retina and retinal pigment epithelium seen in the tilted disc syndrome causes the changes in the ERG and EOG. Pattern VEPs latency was delayed in most patients. This finding is probably due to the poor focusing of the light in the retina.
Suppression and Replacement Gene Therapy for Autosomal Dominant Disease in a Murine Model of Dominant Retinitis Pigmentosa
2011
For dominantly inherited disorders development of gene therapies, targeting the primary genetic lesion has been impeded by mutational heterogeneity. An example is rhodopsin-linked autosomal dominant retinitis pigmentosa with over 150 mutations in the rhodopsin gene. Validation of a mutation-independent suppression and replacement gene therapy for this disorder has been undertaken. The therapy provides a means of correcting the genetic defect in a mutation-independent manner thereby circumventing the mutational diversity. Separate adeno-associated virus (AAV) vectors were used to deliver an RNA interference (RNAi)-based rhodopsin suppressor and a codon-modified rhodopsin replacement gene res…
Temporal resolution and temporal transfer properties: gabaergic and cholinergic mechanisms.
2007
Temporal resolution is a basic property of the visual system and critically depends upon retinal temporal coding properties which are also of importance for directional coding. Whether the temporal coding properties for directional coding derive form inherent properties or critically depend upon the temporal coding mechanisms is unclear. Here, the influence of acetylcholine and GABA upon photopic temporal coding was investigated in goldfish, using flicker stimuli, in a behavioral and an electrophysiological (ERG) approach. The goldfish temporal resolution ability decreased from more than 90% correct choices at 20 Hz flicker frequency to about 65% at 45 Hz flicker frequency with a flicker fu…