Introduction: Transcobalamin (TC) transports cobalamin (vitamin B) from plasma into cells. Its congenital deficiency is a rare autosomal recessive disorder due to mutations in the TCN2 gene. It causes intracellular cobalamin depletion with early onset in the first months of life, failure to thrive with pallor due to megaloblastic anemia.
View Article and Find Full Text PDFIntroduction: Neuronal ceroid lipofuscinoses (CLN) are neurodegenerative disorders among the most frequent, inherited as an autosomal recessive trait. Affected patients can present with progressive decline in cognitive and motor functions, seizures, a shortened life span and visual deficiency. CLN2 is one of the rare CLN that benefits from treatment by cerliponase alpha an enzyme replacement therapy.
View Article and Find Full Text PDFBackground: LCHAD (long-chain 3-hydroxyacyl-CoA dehydrogenase) deficiency is a rare genetic disorder of mitochondrial long-chain fatty acid oxidation inherited as a recessive trait. Affected patients can present with hypoglycaemia, rhabdomyolysis and cardiomyopathy. About half of the patients may suffer from retinopathy.
View Article and Find Full Text PDFBackground: The effects of ethambutol (EMB) on vision are particularly difficult to detect in children less than 5 years of age because of a lack of complaints and objective clinical signs. The aim of this study was to assess the frequency of visual abnormalities and the utility of visual-evoked potentials (VEPs) recordings in monitoring the visual function of children less than 5 years of age who were exposed to EMB during anti-mycobacterial treatment.
Methods: We performed a retrospective study in Robert-Debré University Hospital, Paris, France, including all children less than 5 years of age, who were treated with EMB for a mycobacterial infection from January 2002 to December 2012.
Introduction: Macular dystrophy is a cause of childhood and adult visual handicap and has been associated with multiple gene defects. Syndromic macular dystrophy is rare and a novel congenital form of syndromic macular dystrophy is presented. The authors report on a consanguineous family in which the 5-year-old female proband presented with nystagmus and low vision due to congenital macular dystrophy visible on fundus examination associated with complete corpus callosum agenesis, hippocampi hypoplasia and recurrent illnesses.
View Article and Find Full Text PDFAims: To describe genetic and clinical findings in a French family affected by best vitelliform macular dystrophy (BVMD).
Methods: We screened eight at-risk members of a family, including a BVMD-affected proband, by direct sequencing of 11 bestrophin-1 (BEST1) exons. Individuals underwent ophthalmic examination and autofluorescent fundus imaging, indocyanine green angiography, electro-oculogram (EOG), electroretinogram (ERG), multifocal ERG, optical coherence tomography (OCT), and where possible, spectral domain OCT.
Purpose: To evaluate the effects of levothyroxine (LTh) on the electroretinogram (ERG) of adult dogs.
Material And Methods: Binocular, full field photopic and scotopic ERGs were recorded from an anesthetized Maltese Bichon cross (MB), a Yorkshire Terrier (YT) and a Shetland Sheepdog (SS) affected with hypothyroidism and treated with a daily dose of LTh at 20 microg/kg. The photopic ERGs were evoked to 12 different intensities ranging from 0.
Vision screening of school children at 5-6 years of age must include color vision screening. X-linked dyschromatopsia is the most frequent disorder affecting 8% of boys and 0.4% of girls.
View Article and Find Full Text PDFPurpose: To elucidate the retinal dysfunction and the molecular basis of posterior polymorphous corneal dystrophy (PPCD) associated with macular dystrophy, both inherited in a dominant manner through a three-generation family.
Methods: Ophthalmologic examinations including slit lamp examination, visual acuity tests, fundus visualization by scanning laser ophthalmoscopy, fluorescein angiography, color vision tests, electro-oculography, photopic and scotopic electroretinography (ERG) according to the International Society for Clinical Electrophysiology of Vision (ISCEV) protocols, and oscillatory potential (OP) recordings were conducted on affected family members. Corneal button from one affected patient was examined by transmission electron microscopy.
As previously reported in the literature, the electroretinogram (ERG) of the Beagle dog includes a large post b-wave negativity, the origin of which is not yet established. In the course of our investigations on the electroretinogram in dogs, we examined two Beagle dogs (2 years apart) who had one eye devoid of a Tapetum Lucidum (TL). Photopic (cone-mediated) and scotopic (rod-mediated) ERGs were obtained according to the guidelines for clinical electroretinography in dog.
View Article and Find Full Text PDFElectroretinography, using laboratory animals, is a commonly used technique for determining the retinal toxicity of chemical agents. In this paper, guidelines for performing this test are provided. The physiologic basis for visual testing is presented with attention to inter-species differences.
View Article and Find Full Text PDFThe i-wave, a post b-wave component of the human photopic electroretinogram (ERG), is claimed to originate at the level of the retinal ganglion cells (RGC) or more distally. We investigated whether this wave is a feature common to all species. Photopic ERGs were obtained from the following species: Beagle dog, European cat, New Zealand white rabbit, Göttingen minipig, Cynomolgus monkey, Sprague-Dawley and brown Norway rats, Hartley guinea pig, and CD1 and C57BL6 mice.
View Article and Find Full Text PDFThe early detection of macular toxicity linked to long-term antimalarial treatment requires regular ophthalmological screening based on patients'classification based on their results compared to successive controls. Patients are classified as "low risk" with screening every 18 months if all of the following criteria are met: age under 65 years, no associated renal, hepatic or retinal disease, treatment for less than 5 years, dose less than or equal to 6,5mg/kg/d for hydroxychloroquine and 3mg/kg/d for chloroquine (for a lean patient's weight); "at risk, without fundus findings" with screening every 12 months if one of the following criteria is met: age over 65 years (at the start of or during treatment), antimalarial treatment for more than 5 years, daily dose higher than recommended, presence of renal and/or hepatic disease; "at risk, with fundus findings" with screening every 6 months if a retinal dysfunction has been detected and even if treatment is established or followed. Screening consists of an in-depth clinical examination and at least two complementary tests of macular function: color vision (desaturated-Panel-D15 test) and/or static macular perimetry (central 10 degrees) and/or macular electroretinography (pattern ERG/multifocal ERG).
View Article and Find Full Text PDFERG findings in five sisters are reported. By pedigree analysis, four of the five must be obligate carriers for I-CSNB since their sons were affected (impaired night vision, reduced visual acuity, variable ametropia, congenital nystagmus and ERG with both scotopic and photopic b-wave reduced amplitude). The fifth was childless at the time of examination and her ERG analysis was normal.
View Article and Find Full Text PDFPurpose: To characterize a new animal model of moderate chronic hyperpressure obtained by obstruction of the iridocorneal angle (ICA) in the minipig.
Methods: Intraocular hyperpressure was induced in one eye (left) using an injection of methylcellulose (4%) in the anterior chamber of six healthy adult minipigs. Intraocular pressure (IOP) was measured before injection and at D+60 and D+180.
We present a simple method to record highly reproduciblebinocular electroretinograms in dogs. Rod and cone electroretinograms were elicited in 60 Beagle dogs, with the use of two adjustable photostimulators, one directed at each eye, and maintained in position with the use of a special device. Data analysis revealed no significant differences in amplitudes between the right and the left eye for each animal and each recording session, thus attesting to the high reliability of our approach.
View Article and Find Full Text PDFDisturbances of the optic nerve make up a large part of neuro-ophthalmology. They consist in large part of glaucoma and toxic inflammation of the optic nerve (retro-bulbar optic neuropathy). Progress in the understanding of the function of ganglion cells, in particular the discovery of the M and P pathways, comprise a considerable advance in the comprehension of the optic system as a whole.
View Article and Find Full Text PDFLaurence-Moon syndrome, which is very rare, and Bardet-Biedl syndrome, which is more frequent are now well-recognized as two distinct entities in pediatric neurology. Bardet-Biedl syndrome includes a number of common clinical signs it shares with Laurence-Moon syndrome but also with other syndromes, particularly Alströme syndrome. These signs are retinitis pigmentosa, mental retardation, obesity, and hypogonadism.
View Article and Find Full Text PDFThe micropig is viewed by many as one of the best animal models of human system physiology. The purpose of this study was to develop a simple, rapid and reliable method to record clinical electroretinograms from conscious adult Yucatan micropigs. Photopic ERGs were recorded from 18 conscious animals following a 3-h period of preadaptation to a moderate photopic environment.
View Article and Find Full Text PDFObjective: This study aimed to evaluate more precisely the benefit of macular hole surgery.
Design: The design was a prospective study of 40 eyes in 40 patients examined before and after surgery of full-thickness macular holes with a scanning laser ophthalmoscope (SLO).
Participants: Forty patients with full-thickness macular holes participated.
Electroencephalogr Clin Neurophysiol
November 1995
In a group of 10 children (ranging from 5 months to 15 years old) affected by diseases with mitochondrial dysfunction, 4 suffered from mitochondrial myopathy, 4 from mitochondrial encephalopathy and 2 from Friedreich's ataxia. The clinically detectable visual impairment consisted of 3 grey ocular fundi (the other 7 were normal) associated, in 2 subjects, with a mild nystagmus. Electrophysiological assessment, consisting of ERGs and flash VEPs, was systematically performed.
View Article and Find Full Text PDFPerifoveal laser photocoagulation has been proposed for the treatment of subfoveal neovascular membranes in age-related macular degeneration. We evaluated residual function in seven eyes of six treated patients by means of transient focal visual potentials evoked with a scanning laser ophthalmoscope. The site of the preferred retinal locus was determined.
View Article and Find Full Text PDFA study was designed to validate a functional investigation performed with the scanning laser ophthalmoscope before surgery for macular holes in 12 eyes: The assessment included fundus examination, a functional examination resulting in evaluation of the preferred retinal lows, visual acuity and recording of visual evoked potentials. The preferred retinal locus was evaluated by presenting a small square area, and visual acuity was determined by means of calibrated figures. The visual evoked potentials were evoked by three alternating checkerboards (check size, 30', 2 Hz) centered over the hole and seen at an angle of 6.
View Article and Find Full Text PDFThe retinal location of preferential fixations of twenty-four patients with central scotoma were studied when reading digits projected onto their retina with a scanning laser ophthalmoscope. In the majority of cases the fixation was located on the left part, or the inferior part of the visual field relative to the central scotoma. The fact that the inferior visual field is used is coherent with the notion that the lower visual field is important for locomotion.
View Article and Find Full Text PDFWe compared the focal visual evoked potentials obtained in 52 young subjects with normal vision, evoked by means of three alternating black/color checkerboards generated by a trichromic cathode ray tube (dominant wavelength, 514 nm; colorimetric purity, 0.45) and by means of a scanning laser ophthalmoscope (argon laser beam, 514 nm; colorimetric purity, approximately 1). These three checkerboards, with an area of 3.
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