Journal Article•
Electroretinography: Some basic principles.
01 Aug 1970-Investigative Ophthalmology & Visual Science (The Association for Research in Vision and Ophthalmology)-Vol. 9, Iss: 8, pp 557-569
About: This article is published in Investigative Ophthalmology & Visual Science.The article was published on 1970-08-01 and is currently open access. It has received 169 citations till now.
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TL;DR: How the study of CSNB has increased understanding of the mechanisms of visual signalling in the retina is highlighted, likely to prove important in developing future treatments for CSNB and other retinal disorders.
249 citations
Journal Article•
TL;DR: Findings indicate that for clinical patient evaluation, age-corrected normal ranges derived from linear or multiple regression coefficients should be used for rod- and cone-mediated b-wave response, whereas normal rangesderived from mean and standard deviation are more appropriate for scotopic a-wave amplitude,Scotopic cone- mediated x-wave amplitudes, and for all implicit times.
Abstract: The ganzfeld-evoked electroretinogram (ERG) is the most effective measure of the mass electrical response of cones and rods; however, all variables affecting the various components of the ERG have not been identified. The scotopic b-wave amplitude has been appreciated to be age-dependent, but little or no information exists in the literature regarding age dependency for other components. Linear regression analysis against age and multiple regression analysis against age and log intensity of the stimulus were performed on ERG responses from 24 prospectively normal subjects. Significant age dependency was found for scotopic rod-mediated b-wave amplitude, scotopic mixed rod-and cone-mediated bx-wave amplitude, and for photopic cone-mediated and b-wave amplitude. No significant age correlation was found for dark-adapted cone a-wave amplitude, scotopic cone-mediated x-wave amplitude, scotopic a-wave amplitude from mixed rod and cone responses to bright stimuli, or for implicit times for any scotopic or photopic responses. These findings indicate that for clinical patient evaluation, age-corrected normal ranges derived from linear or multiple regression coefficients should be used for rod- and cone-mediated b-wave response, whereas normal ranges derived from mean and standard deviation are more appropriate for scotopic a-wave amplitude, scotopic cone-mediated x-wave amplitude, and for all implicit times.
222 citations
TL;DR: The ERG seems to be a useful clinical tool in predicting the rate of progression of diabetic retinopathy, and the reduction in OP amplitudes probably is a quantitative measure of the degree of overall inner layer retinal ischemia.
Abstract: The oscillatory potential (OP) amplitudes of the electroretinogram (ERG) were determined in a group of 85 diabetic patients entering the Early Treatment Diabetic Retinopathy Study (ETDRS). The rate of progression among nonphotocoagulated eyes to the Diabetic Retinopathy Study high-risk characteristics (DRS-HRC) during a ten- to 40-month follow-up period was determined. Progression occurred in 19 of 85 eyes at risk. Those eyes with abnormal OP amplitudes (less than or equal to 75 microV) at study entry had a tenfold higher rate of progression to DRS-HRC than did eyes with normal amplitudes (greater than 75 microV). Although the level of retinopathic severity at study entry was a significant factor in the rate of subsequent progression, the amplitudes of the OPs remained a significant risk factor even after correcting the initial retinopathic level. The ERG seems to be a useful clinical tool in predicting the rate of progression of diabetic retinopathy. The reduction in OP amplitudes probably is a quantitative measure of the degree of overall inner layer retinal ischemia.
183 citations
TL;DR: The identification of the mutant genes causing forms of stationary night blindness refines the classification of these diseases and enhances the understanding of the underlying physiologic defects.
160 citations
TL;DR: In this paper, the effects on human vision of a mutation in the RK gene causing Oguchi disease, a recessively inherited retinopathy, were investigated in vitro and in vivo.
Abstract: Rhodopsin kinase (RK), a specialized G-protein-coupled receptor kinase expressed in retina, is involved in quenching of light-induced signal transduction in photoreceptors The role of RK in recovery after photoactivation has been explored in vitro and in vivo experimentally but has not been specifically defined in humans We investigated the effects on human vision of a mutation in the RK gene causing Oguchi disease, a recessively inherited retinopathy In vitro experiments demonstrated that the mutation, a deletion of exon 5, abolishes the enzymatic activity of RK and is likely a null Both a homozygote and heterozygote with this RK mutation had recovery phase abnormalities of rod-isolated photoresponses by electroretinography (ERG); photoactivation was normal Kinetics of rod bleaching adaptation by psychophysics were dramatically slowed in the homozygote but normal final thresholds were attained Light adaptation was normal at low backgrounds but became abnormal at higher backgrounds A slight slowing of cone deactivation kinetics in the homozygote was detected by ERG Cone bleaching adaptation and background adaptation were normal In this human in vivo condition without a functional RK and probable lack of phosphorylation and arrestin binding to activated rhodopsin, reduction of photolyzed chromophore and regeneration processes with 11-cis-retinal probably constitute the sole pathway for recovery of rod sensitivity The role of RK in rods would thus be to accelerate inactivation of activated rhodopsin molecules that in concert with regeneration leads to the normal rate of recovery of sensitivity Cones may rely mainly on regeneration for the inactivation of photolyzed visual pigment, but RK also contributes to cone recovery
154 citations