背景光强度与视网膜电图振荡电位

目的：定量分析不同强度背景光照明下,视网膜电图(electroretingogram,ERG)振荡电位(oscillatory potemtials,OPs)各子波的变化,探讨背景光照明对振荡电位子波的影响。方法：记录出生25-29天Albino鼠暗视及四个不同强度背景光(“弱”、“次弱”、“次强”、“强”)照明下全视野ERGa波,b波和振荡电位。刺激闪光和背景照明光源均为白炽灯。刺激闪光强度1．43×10^2cd/m^2,闪光时程75ms,闪光间隔时间1分钟;背景照明光强度1．43×l0^-6-1．43×l0^0cd／m^2,以二个对数单位分级。结果：振荡电位各子波在不同强度背景光照明下反应不同,“弱”背景光照明下,O1和O2振幅增高;O1振幅在“次弱”背景光照明时增高更明显;在“次强”背景光照明下,O1和02消失,O3、O4和O5,均显著增高;当采用“强”背景光照明时,所记录的O3和O4振幅显著下降,O5振幅无变化。同时记录的ERGa波和b波在“次强”和“强”背景光照明下振幅显著降低。除O2峰时在“次弱”照明时显著延长外,其余子波在二个弱背景光照明下峰时无变化;但在二个强背景光照明下,O3、O4和O5峰时均明显缩短。结论：Albino鼠眼振荡电位各子波在不同强度背景光照明下的不同反应提示它们在视网膜的起源不同。弱背景光照明下短峰时子波活跃而强背景光照明时长峰时子波活跃,提示短峰时子波可能与暗视系统相关而长峰时子波则与明视系统相关。     

视网膜电图振荡电位的振幅测定方法的探讨

通过对正常人ERG的振荡电位(OPs)的几种不同的测定方法的对比,了解了各种测定方法的OPs总振幅和O_1振幅与a波振幅的相互关系,从而提出了一种简便且又受a波振幅影响最小的OPs总振幅测定方法,并建议在临床工作中采用之。     

视网膜电图振荡电位波节个数分析

视网膜电图振荡电位波节个数分析解放军总医院眼科王红视网膜电图的振荡电位（ｅｌｅｃｔｒｏｒｅｔｉｎｏｇｒａｍｓ－ｏｓｃｉｌｌａｔｏｒｙＰｏｔｅｎｔｉａｌｓ，简称ＥＲＧ－ｏＰｓ），是一项视网膜生理功能的检查，它反映了视网膜的血液循环状态。ＯＰＳ是ＥＲＧ中...     

视网膜电图振荡电位及其在临床中的应用

视网膜电图的振荡电位 (oscillatory potentials,OPs)是叠加在 ERG b波上升枝的数个小而快的有节律的一串子波。6 0年代初期国外逐渐应用于眼科临床电生理检查中。较为公认的看法是 :振荡电位起源于内层视网膜 ,可能是代表从无长突细胞到双极细胞间的抑制性反馈回路。振荡电位对糖尿病视网膜病变的早期诊断 ,预测增殖性视网膜病变的危险性及提供激光治疗的适应证均具有重要意义。研究表明 ,振荡电位对中央静脉阻塞的早期诊断和分型是一种敏感而可靠的方法 ;振荡电位对静脉阻塞在判定病情及预后有着重要的意义 ;视网膜脱离患者患眼的振荡电位振幅降低甚或消失 ,峰时间延迟     

老年性黄斑变性视网膜电图及振荡电位的测定

采用美国NicdetCompactⅣ型视觉电生理仪对31例（36眼）老年性黄斑变性（AMD）进行了闪光视网膜电图（PERG）及振荡电位（OPs）的测定。证实AMD视杆细胞系统和视锥细胞系统都不同程度的损害。     

早期糖尿病视网膜病变患者视网膜电图振荡电位和色觉检测

目的　探讨早期糖尿病视网膜病变 (diabetic retinopathy,DR)患者视网膜电图 (electroretinogram ,ERG)振荡电位 (oscillatory potentials,OPs)和色觉监测的指标。方法　尚无 DR改变 (DR0期 )的糖尿病患者和DR1期患者共 70例 (134眼 )分别用 Neuropack- 电生理仪测试 ERG OPs及用 FM- 10 0 Hue色相子排列法检查色觉 ,并与 30例 (5 9眼 )正常人的测试结果相比较。两种检查的测试结果亦作比较分析。结果　糖尿病组 OPs各小波潜伏期延长 ,振幅及各子波振幅总和下降 (P <0 .0 5 ) ,异常率为 40 .3%。除 OP3振幅外 ,DR1期组各波振幅及振幅总和低于 0期组 (P <0 .0 5 )。色觉异常率为 39.6 % ,轴向分析表明全部为蓝色觉异常 ,1期患者比 0期的平均错误分高 (P <0 .0 5 )。二者检查结果有良好一致性 (x2 =12 .1,P <0 .0 0 5 ) ,但检出率无显著差异 (x2 =0 ,P >0 .0 5 )。结论　 ERG OPs和色觉检查可作为评价患者视功能及 DR进展的指标 ,有利于对糖尿病患者进行跟踪随访及 DR的早期防治 ,具有一定的临床应用价值。     

背景光照明强度对视网膜电图和振荡电位的影响

目的观察不同强度背景光照明下视网膜电图(electroretinogram, ERG) 和振荡电位(oscillatory potentials, OPs)的变化,了解视网膜神经性调控机制对环境照明改变的反应。方法应用自行设计的全视野刺激的ERG记录仪,采用 DTL纤维电极于角膜端记录出生25~29 d Albino鼠(Wistar Fu)眼在暗视及以2个对数单位递增的4个背景光强 度 ——“弱”(1.43×10^-6cd/m²)、“次弱”(1.43×10^-4cd/m²)、“ 次强”(1.43×10^-2cd/m²)和“强”(1.43×10^-2cd/m²)下的ERG a波和b 波。采用数字式滤波器,同时记录OPs。刺激闪光强度为1.43×10^-2cd/m²,闪光时程75 ms,闪光间隔时间1 min 。结果随着背景照明强度的增强,OPs子波数由5个减少至3个,但子波振幅总和增加。当背景光强度增强到最强水平,OPs振幅总和减少。ERG a波和b波振幅在2个弱背景光照明下未见改变。但在强背景照明范围,a波和b波振幅随照明强度的增强而呈下降趋势。结论Albino鼠视网膜内层存在的神经调控系统对环境照明改变的反应比感光细胞更敏感、更快。记录OPs时采用适当的连续背景光照明,可提高反应记录的稳定性。(中华眼底病杂志,2001,17:286-288)     

视网膜电图振荡电位的提取及定量技术的进展

视网膜电图振荡电位（OPs）是叠加在视网膜电图（ERG）中b波上升支的数个高频率、有节律的小波。因为OPs是反应视网膜内层功能的一个敏感指标,国际临床视觉电生理学会（ISCEV）把它列入5项检查指标之一。OPs的准确采集取决于滤波器的正确使用,然而由于提取OPs时滤波器参数设置不当,很多研究未能将OPs中所包含的ERG低频率成分剔除,得到的并非是纯净的OPs。此外,传统的OPs计量方法是将OPs各子波振幅累加而得。这种测量方法受低频率成分的干扰导致可靠性和重复性差,明显影响OPs的分析。正确设置滤波器可得到纯净的OPs。用积分的方法计算OPs信号频谱曲线下的面积即振幅能量的方法可准确计量OPs。     

Spatial characteristics of the oscillatory potentials of the electroretinogram

The spatial properties of the trans- and intra-retinal oscillatory potentials (OPs), a- and b-waves of the mudpuppy electroretinogram (ERG) were analyzed. A comparison of the intra-retinal potentials was made with the proximal negative response (PNR), an extracellular response, predominantly from amacrine cells. The spatial characteristics of the OPs differed from the a- and b-waves and the PNR. The OPs integrated spatially up to full field illumination. They seem to represent summated neuronal activity over broader areas than that of the PNR and the a- and b-waves. The results indicate that the OPs reflect activity of second order neurons to which visual information converge from the whole retina. These neurons may be the bipolar cells. No evidence that the OPs orginate in the laterally extending amacrines was obtained. The b-wave data further suggested a centre-surround organization for the neurons indirectly involved in the b-wave generation.     

Origins of the electroretinogram oscillatory potentials in the rabbit retina

The electroretinogram (ERG) oscillatory potential (OP) is a high-frequency, low-amplitude potential that is superimposed on the rising phase of the b-wave. It provides noninvasive evaluation of inner retina function in vivo and is a useful tool in basic research as well as in the clinic. While the OP is widely believed to be generated mainly by activity of the inner retina, the exact underlying neural mechanisms are not well understood. We have investigated the retinal mechanisms that underlie OP generation in Dutch-belted rabbits. The OP was isolated by band-filtering (100-1000 Hz) ERG signals. We used pharmacological agents that block specific transmitter receptors or voltage-gated channels in order to examine contributions of various retinal mechanisms to OP generation. Our results show that the OP elicited by a bright brief flash can be classified into early, intermediate, and late subgroups that are likely generated mainly by photoreceptors, action-potential-independent, and action-potential-dependent mechanisms in the ON pathway of the inner retina, respectively. ON bipolar cells themselves make only a small direct contribution to OP generation, as do horizontal cells and neurons in the OFF pathway.     

Changes in the oscillatory potentials of the electroretinogram in glaucoma

Dark adapted and progressively light adapted electroretinograms (ERGs) were recorded from 34 normals and from 45 glaucoma patients. To enhance the oscillatory potentials (OP) the ERGs were highpass-filtered. The OP were characterized by two indices: their root-mean-square value and the inter-flash interval for which the maximal amplitude was obtained. In most of the glaucomatous OP, 50 of 81 eyes, both indices were abnormal, in 22 one parameter was abnormal and only in 9 were both parameters normal. In 13 of the 14 OP recorded from the opposite ('normal') eye of patients with unilateral glaucoma either one or both of the indices were abnormal. These findings indicate that the damage to the retina in glaucoma may extend more distally than the ganglion cell layer and that subclinical changes might be revealed by OP changes.     

Recording the oscillatory potentials of the electroretinogram with the DTL electrode

Suprathreshold photopic oscillatory potentials recorded with a DTL electrode were compared to those obtained with a Lovac corneal electrode. The overall oscillatory potential response (sum of oscillatory potentials) recorded with the DTL electrode was half of that obtained with the Lovac electrode. However, there was no evidence of a selective attenuation (or amplification) of any given oscillatory potential with the DTL electrode. Similarly, the oscillatory potential relative amplitude ratios and the peak times of the oscillatory potentials were identical for both electrodes. Our findings clearly indicate that the DTL electrode is adequate to record the high-frequency oscillatory potentials. Given the low cost and ease of use, as well as the disposable nature of the DTL electrode, we believe that electroretinographic specialists should seriously consider a wider utilization.     

Basic research and clinical aspects of the oscillatory potentials of the electroretinogram

This paper reviews current knowledge concerning the oscillatory potentials (OPs) of the electroretinogram (ERG). The first section describes the basic characteristics of the OPs primarily studied in healthy subjects. The behavior of the OPs is different from the a- and b-waves, indicating separate mechanisms for generation of the OPs compared with the major components of the ERG. The second section deals with the present view of the origin of the OPs collected from experimental studies of the vertebrate retina, including the primate. Findings favor the conclusion that the bipolar (or interplexiform) cells are the probable generators of the OPs. The third section gives clinical examples of the sensitivity of OPs to early disturbances of retinal function in different eye diseases.