Electroretinographic oscillatory potentials in diabetic retinopathy
People's Hospital, Beijing Medical UniversityDocumenta Ophthalmologica (Impact Factor: 1.63). 05/1992; 81(2):173-179. DOI: 10.1007/BF00156006
The oscillatory potentials of the electroretinogram in dark and light adaptation were evaluated by Fourier transform in 87 diabetics and 74 age-matched controls. The study consisted of four groups: normal control, no observable diabetic retinopathy, background diabetic retinopathy and proliferative diabetic retinopathy. A reduction in the amplitude of each oscillatory potential, the summed amplitudes, the area and the total power of the oscillatory potentials as well as delayed implicit time of each oscillatory potential peak in dark and light adaptation could be found in patients with background diabetic retinopathy and proliferative diabetic retinopathy. The amplitude of oscillatory potential 4 in dark adaptation and the total power of the oscillatory potentials in light adaptation seemed to be affected in patients with no observable diabetic retinopathy. The implicit time of oscillatory potential 2 in dark adaptation was valuable to distinguish between patients with no observable diabetic retinopathy and background diabetic retinopathy.
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ABSTRACT: In cross-sectional fashion, we recorded the maximal combined response and 30-Hz flicker responses in 178 adult diabetics and 40 normal controls according to the recommendations of the International Society of Clinical Electrophysiology of Vision. The oscillatory potentials were extracted from the maximal combined response by high-pass filtering. The clear media and attached retina were criteria for inclusion in this study. The data were statistically analyzed with the expectation that this procedure may provide a new feature that could have some clinical significance. Timing delays occurred more frequently than amplitude reductions in the maximal combined response and flicker responses, while amplitude reductions were more common in the first and second oscillatory potentials. The hypernormal b-wave amplitude was rare. The summed amplitude of the oscillatory potentials was highly correlated with the total power of the oscillatory potentials (the frequency domain). A reduction of the second oscillatory potential amplitude was more common than a reduction of the summed amplitude or total power. The electroretinographic component that demonstrates retinal dysfunction in the earlier stage may be a valuable indicator. In the early stage, a delay in the a-wave time and a reduction in the second oscillatory potential amplitude were the most frequent abnormalities: analysis of variance demonstrated that the summed amplitude of the oscillatory potentials and second oscillatory potential amplitude and time were the most sensitive measures of the diabetic retina. Hence, the second oscillatory potential amplitude may be the most sensitive and valuable indicator representing a quantitative measure of overall retinal dysfunction.Documenta Ophthalmologica 09/1997; 94(3):201-13. DOI:10.1007/BF02582979 · 1.63 Impact Factor
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ABSTRACT: This chapter is an overview of current knowledge on the oscillatory potentials (OPs) of the retina. The first section describes the characteristics of the OPs. The basic, adaptational, pharmacological and developmental characteristics of the OPs are different from the a- and b-waves, the major components of the electroretinogram (ERG). The OPs are most easily recorded in mesopic adaptational conditions and reflect rapid changes of adaptation. They represent photopic and scotopic processes, probably an interaction between cone and rod activity in the retina. The OPs are sensitive to disruption of inhibitory (dopamine, GABA-, and glycine-mediated) neuronal pathways and are not selectively affected by excitatory amino acids. The earlier OPs are associated with the on-components and the late OPs with the off-components in response to a brief stimulus of light. The postnatal appearance of the first oscillatory activity is preceded by the a- and b-waves. The earlier OPs appear postnatally prior to, and mature differently from, the later ones. The second section deals with present views on the origin of the OPs. These views are developed from experimental studies with the vertebrate retina including the primate retina and clinical studies. Findings favor the conclusion that the OPs reflect neuronal synaptic activity in inhibitory feedback pathways initiated by the amacrines in the inner retina. The bipolar (or the interplexiform) cells are the probable generators of the OPs. Dopaminergic neurons, probably amacrines (or interplexiform cells), are involved in the generation of the OPs. The earlier OPs are generated in neurons related to the on-pathway of the retina and the later ones to the off-channel system. Peptidergic neurons may be indirectly involved as modulators. The individual OPs seem to represent the activation of several retinal generators. The earlier OPs are more dependent on an intact rod function and the later ones on an intact cone system. Thus, the OPs are good indicators of neuronal adaptive mechanisms in the retina and are probably the only post-synaptic neuronal components that can be recorded in the ERG except when structured stimuli are used. The last section describes the usefulness of the oscillatory response as an instrument to study the postnatal development of neuronal adaptation of the retina. In this section clinical examples of of the sensitivity of the OPs for revealing early disturbance in neuronal function in different retinal diseases such as pediatric, vascular and degenerative retinopathies are also given.Progress in Retinal and Eye Research 11/1998; 17(4):485-521. DOI:10.1016/S1350-9462(98)00006-8 · 8.73 Impact Factor
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ABSTRACT: Persons with type 1 diabetes show electrophysiological abnormalities of the visual system which are revealed by methods such as flash electroretinogram (FERG), oscillatory potentials (OPs), pattern electroretinogram (PERG), focal electroretinogram (focal ERG), visual evoked potentials (VEP) in basal condition and after photostress. This review reports the changes in electrophysiological responses of the different structures composing the visual system observed in persons with type 1 diabetes before the development of the overt clinical retinopathy. In persons with type 1 diabetes without retinopathy (IDD), the earlier abnormal electrophysiological responses are recorded from the innermost retinal layers and postretinal visual pathways, as suggested by impaired PERGs and delayed retinocortical time (RCT). These are observed in IDD persons with a disease duration shorter than 6 months. Further electrophysiological changes are recorded from the macula (abnormal focal ERG and VEP after photostress) in IDD persons with disease duration greater than 1 year. Additional electrophysiological changes are recorded from the middle and outer retinal layers (impaired FERG and OPs) in IDD persons with a disease duration greater than 10 years. All the electrophysiological tests show a greater degree of abnormal responses in persons with type 1 diabetes when a background retinopathy is present.Diabetes/Metabolism Research and Reviews 01/2001; 17(1):12-8. DOI:10.1002/dmrr.177 · 3.55 Impact Factor
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