正常青年人多焦视网膜电图的特点及记录方式的影响

目的 观察正常青年多焦视网膜电图(mERG)特点，比较不同记录条件对mERG结果的影响。方法 健康青年15例(30眼)按单限及双眼同时记录的不同顺序随机进行检测，并在同一眼上采用不同电极分别记录。结果 被试者的mERG中注视点区域波幅值最高，随离心度增加而降低，峰时值也呈相似变化，注视点区域峰潜时最长。单眼分别检测与双眼同时检测时，各相应指标无显著差异，而使用不同电极检查结果有显著差异。结论 采用单眼分别记录或双眼同时记录mERG对检查结果没有明显影响，不同记录电极对检查结果影响较大，其中jet角膜接触镜电极记录的效果比较稳定、可靠。     

多焦视网膜电图评价视网膜脱离的视网膜功能

目的 探讨多焦视网膜电图(multifocal electroretinography, MERG)对视网膜脱离(retina detachment, RD)的视功能客观评价意义。 方法 应用VERIS 4.0视诱发反应图像系统检测21例RD患者的22只患眼和36例正常人的42只眼的MERG。测试野的水平视角为±26.6°,垂直视角为±22.1°,采用Burian-Allen接触镜电极,在8 min(分16段)记录103个视网膜部位的反应。 结果RD眼于4个象限、黄斑区和黄斑外区MERG a波、b波潜伏期及b波振幅密度、振幅之和均明显低于正常对照组(P<0.01);脱离区、非脱离区和正常眼的 MERG b波振幅密度分别为(3.44±2.85)、(6.34±3.31)、(21.32±6.48)nV/deg²,三者之间的差异均有非常显著性意义(P<0.05)。 结论 多焦ERG能客观定量评价RD的黄斑部、后极部的脱离区和非脱离区的视功能。(中华眼底病杂志,2000,16:244-247)     

多焦视网膜电图的年龄相关性

目的　确定多焦视网膜电图 (M ERG)的正常值 ,分析后部视网膜不同区域电生理功能与年龄的相关性。方法　对 3 8例 ( 3 8眼 )不同年龄段的散瞳正常眼做M ERG检查 ,分析第 1个负波 (P1波 )、第 1正波 (N1波 )的潜伏期和反应密度及与年龄的关系。结果　总反应波、4个象限、环 1～ 6的反应密度随年龄的增长而下降 (P <0 0 1) ;总反应波、鼻侧、环 5 ,6的N1波潜伏期 ,以及总反应波、鼻侧、颞上象限、环 2 ,3 ,4,6的P1波潜伏期随年龄增长而延长。尤其颞上象限、环 5 ,6的反应密度在老年组下降更明显。结论　后部视网膜的功能随年龄增长而降低。     

正常人多焦视网膜电图的特征

目的:探讨正常人多焦视网膜电图(multicalelec-troretinogram,mERG)在视网膜的分布特征,以获得正常参考值。方法:应用法国Metrovision公司生产的VisionMonitor视觉诱发系统检测15例(24眼)正常人mERG,检测视野的水平视角±30°,垂直视角±23°,采用ERG-jet接触镜电极,于5min记录61个视网膜部位的反应。结果:黄斑中心凹N1波、P1波、N2波的振幅密度最大,分别为(47.26±19.51)nV/deg2,(118.22±45.08)nV/deg2,(127.55±38.83)nV/deg2,向周边振幅密度逐渐降低;N1波、P1波的颞侧振幅密度较鼻侧大;P1波、N2波的颞上区振幅密度较鼻下区大。黄斑中心凹P1波、N2波的潜伏期均较其他各区缩短。结论:mERG的各波振幅密度与视网膜感光细胞的分布基本一致,能准确、客观的反映视网膜各部位的功能。     

多焦视网膜电图的研究概况

多焦视网膜电图(multifocal electroretinogram,mERG)作为临床视觉电生理的最新进展正在全世界逐渐推广应用本文阐述了近年来对mERG的研究状况，包括我国正常人mERG的特征，及mERG在视网膜病变中的应用。     

视网膜电图和多焦视网膜电图视杆细胞ON和OFF反应记录研究

目的:研究全视野视网膜电图(electroretinogram,ERG)和多焦视网膜电图(multifocal eletroretinogram,mf-ERG)视杆细胞ON和OFF反应记录条件并分析其波形特征。方法:2例正常人放瞳、暗适应30 min后,分别采用矩形刺激(rectangle stimulus)、锯齿状的 rapid on和rapid off刺激模式记录反应波形,并改变刺激强度和频率观察波形变化。采用模拟矩形刺激、锯齿状的rapid on和rapid off刺激模式记录mf-ERG波形。结果:ERG采用矩形和rapid-on刺激模式可记录到大的正向波,随刺激频率增加,振幅减小, 潜伏时变化不明显。采用rapid-off刺激模式记录到小的负向波,潜伏时80 ms左右,在负向波下降支近波谷处可见小的正向波。随刺激频率增加,负向波潜伏时延长,而小正向波振幅逐渐减小。当刺激频率大于3 Hz时,上述反应均出现类似振荡电位波形。mf-ERG采用模拟矩形和模拟rapid-on刺激模式可记录到大的正向波,其波形特征与ERG矩形刺激模式的波形类似;采用模拟rapid-off刺激模式仍可记录大的正向波,但其后出现较大陡峭的负向波。结论:采用锯齿状的rapid-on和rapid-off刺激模式可以记录到视杆细胞ON和OFF反应,视杆细胞OFF反应的负向波下降支近波峰处存在小的正向波,采用模拟的rapid-on刺激模式记录到mf-ERG视杆细胞ON反应。建议记录ERG视杆细胞ON和OFF反应采用0．5-1Hz 刺激频率和低强度刺激光。将来可利用这些刺激模式研究视网膜疾病,具有一定的临床价值。     

视杆细胞多焦视网膜电图记录探讨

常规mERG记录是明视条件下记录锥细胞功能，本研究探索用多焦刺激技术记录视枰细胞功能。     

正常人多焦图形视网膜电图的特征

目的　检测正常人多焦图形视网膜电图 (m PERG)特征。方法　 2 0只正常眼 ,罗兰视觉电生理仪行m PERG检查 ,重复测试 5次。记录波形成分并进行统计学处理。结果　P1、N1波 :第 1至 5环间的振幅密度值逐渐下降(P <0 0 1) ,差异无显著性 (P >0 0 5 ) ,颞侧视网膜的峰时较鼻侧延长峰时差异无显著性 (P >0 0 5 ) ,4个象限间的振幅密度值差异有极显著性 (P <0 0 1) ,上下半部视网膜的振幅密度值和峰时差异均无显著性 (P >0 0 5 )。N1波峰时 :颞上较鼻上、鼻下象限 ,颞下较鼻上、鼻下象限延长 (P <0 0 1)。结论　多焦视网膜电图能定位、定量地反映视网膜神经节细胞功能 ,为临床提供正常参考值     

复杂性视网膜脱离的多焦视网膜电图研究

目的 探讨多焦视网膜电图（mfERG）对复杂性视网膜脱离（RD）视功能客观评价的意义。方法 应用VERIS ScienceTM 4．2mfERG检测仪对80例复杂性RD患者的双眼进行检测,并与正常对照组比较。结果 复杂性RD患者的对侧眼、患眼在6个环的N1波、P1波振幅密度较正常对照组降低,潜时延长,差异均有统计学意义（P〈0．01）。有严重玻璃体积血组的N1、P1波振幅密度在2～6环高于无严重玻璃体积血组,差异均有统计学意义（P〈0．05）。重度PVR组的N1、P1波振幅密度低于轻度PVR组,在6个环差异均有统计学意义（P〈0．05）。黄斑裂孔组在所有6个环的N1、P1波振幅密度较正常对照组降低,潜时延长,差异均有统计学意义（P〈0．01）。结论 mfERG能客观定量评价复杂性RD患者的视功能。严重的玻璃体积血、黄斑裂孔、PVR对视功能有明显影响。     

我国正常人多焦视网膜电图的特征

目的　检测我国正常人多焦视网膜电图（electroretinogram,ERG）的特征,以探讨其正常参考值。方法　应用VERIS4.0视诱发反应图像系统检测42例(48只眼)正常人多焦ERG,检测对象年龄11～67岁,平均40.7岁。检测视野的水平视角为±26.6°,垂直视角为±22.1°,采用Burian-Allen接触镜电极,于8min(分16段)记录103个视网膜部位的反应。结果　随被检测者年龄增长,多焦ERG的N1波和P1波潜伏期延长,<50岁与≥50岁年龄组间比较差异有显著性(t值均>2.01,P值均<0.05);N1波和P1波振幅密度降低,个体间变异较大,在中央凹N1波和P1波的振幅密度最大,分别为(44.88±13.30)nV/deg     

视网膜色素变性的多焦视网膜电图

目的研究视网膜色素变性（ＲＰ）的多焦视网膜电图（ＥＲＧ）特性和评价多焦ＥＲＧ应用价值。方法检测了 １２例（２４眼）ＲＰ患者的多焦 ＥＲＧ,测试野为２６．６°×２２．１°,记录 １０３个部位的反应,同时检测全视野 ＥＲＧ。结果ＲＰ眼在各个环的ａ波和ｂ波潜伏期、ｂ波振幅密度和振幅之和均较正常值有显著延长和降低（Ｐ＜０．０５或Ｐ＜０．０１）。５０％患眼在第１环可记录到潜伏期正常、振幅密度和总和均降低的ｂ波,而７５％患眼的全视野ＥＲＧ呈平坦反应。结论 多焦ＥＲＧ能更有效地评价ＲＰ的黄斑区功能。     

The multifocal electroretinogram in X-linked juvenile retinoschisis

To measure and compare the multifocal electroretinography in normal control and X-linked juvenile retinoschisis, 13 cases (13 right eyes) of normal control and nine cases (17 eyes) of X-linked juvenile retinoschisis were measured with VERIS Science 4.0. Four cases (eight eyes) out of the nine retinoschisis cases were tested with Ganzfeld ERG at the same day. The results showed statistically significant difference of average response densities and latencies in six ring retinal regions between the normal control and retinoschisis. The trace array and 3-D topography of multifocal ERG showed multi-area amplitude decrease with absence or reduction of central peak amplitude in patients with retinoschisis. The P₁/N₁ ratio of multifocal ERG average response densities in six ring retinal regions was different from the b/a ratio of Ganzfeld ERG. The multifocal ERG and Ganzfeld ERG each had its advantage in the diagnosis of retinoschisis.     

The impact of fixation on the multifocal electroretinogram

There are a number of variables which can influence the quality of multifocal ERG waveforms. In common with visual field measurements, fixation quality may be an important parameter on the integrity of the acquired data. A low cost, fixation-monitoring device was used to assess fixation quality on a group of normal volunteers. Data was successfully acquired while five subjects viewed a fixation target for a period of time equal to that of a single multifocal recording segment. The target was presented on a stationary grey background and as the central fixation mark on a 61-element multifocal flicker stimulus. The results show no significant difference with or without the flickering pattern. The percentage of samples falling within 1.2° of the point of fixation was 51%. This suggests that fixation quality is adequate for scaled stimuli where the central element subtends 2.4°. High resolution stimuli of less than 2.4° may be more susceptible to fixation fluctuations during the recording process.     

多焦视网膜电图的临床应用进展

多焦电生理技术可在相对较短的时间内记录测试野内许多局部视网膜电图的反应波形,有助于了解视网膜或视路病变的机制,可用于一些眼病的早期诊断及预后,能客观和敏感地观察药物或手术的疗效。现将多焦视网膜电图在眼科临床中的研究进展作一综述。     

The effect of filter bandwidth on the multifocal electroretinogram

The effect of filter bandwith on the multifocal electroretinogram was assessed by means of theoretical calculation, electronic simulation and real multifocal electroretinogram recordings. Waveform distortion by high-pass filtering on simulated square waves, normal electroretinogram waveforms and negative electroretinogram waveforms was demonstrated. The theory of the effect of differentiation on electroretinographic waveform shape by electronic filtering indicates that little effect would be observed by changing the input filter cut-off for normal electroretinographic waveform shapes. However, negative electroretinogram waveforms are differentiated when the high-pass filter setting is increased. The differentiation effect artificially recreates a positive component that could be mistaken as a b-wave component. To eliminate this effect when recording multifocal electroretinograms, a high-pass filter setting of less than 1 Hz should be used to preserve the true electroretinographic waveform shape.     

Oscillatory potentials of multifocal electroretinogram retinopathy

Purpose: To investigate the physiological function in the posterior pole of the retina in eyes with preproliferative diabetic retinopathy using the oscillatory potentials (OPs) of the multifocal electroretinogram (mfERG). Methods: Multifocal ERGs were recorded from 61 eyes of 61 patients with preproliferative diabetic retinopathy (pre-PDR) and 16 eyes of 16 age-similar normal control subjects. The amplitudes and implicit times of the first positive component, P1, and the OPs of the mfERGs, recorded with a slow m-sequence, from diabetics were compared with those in normal control subjects. Among the 61 eyes, the mfERGs were recorded before and after panretinal photocoagulation (PRP) in 19 eyes of 19 patients. Results: The amplitudes of P1 and OPs were significantly smaller in all tested areas in the diabetics as compared with those in the normal subjects, and the degree of reduction was greater for the OPs than P1. The implicit times of P1 and OPs were significantly delayed in the diabetics in the peripheral tested regions (20–40°) but not in the central area. After PRP, the amplitudes of P1 were markedly reduced in all areas tested; however, the changes of the P1 implicit time were not significant. The amplitudes of the OPs were significantly reduced in the peripheral regions after PRP; however, the changes in the implicit times were not significant. Conclusions: These results indicate that retinal function in the posterior pole is markedly impaired in eyes with pre-PDR. PRP altered the mfERGs significantly, however, the reductions were limited to the amplitude.     

Effects of refractive blur on the multifocal electroretinogram

A significant difference in the response density of the MF-ERG response has been suggested for every 2 diopter change of refraction. The influence of refractive blur on the MF-ERG was studied in 8 healthy volunteers using either the VERIS™ system (Group A: n=5) or Retiscan™ (Group B: n=3). For each eye recordings were obtained with a corrective lens of −3 dpt, 0 dpt, +3 dpt and +6 dpt placed in front of the contact lens electrode. The viewing distance was adjusted to compensate for the induced changes in the retinal image size. When the changes in retinal image size due to the refractive lens were compensated for, no influence due to refraction was observed in either latencies or amplitudes of (KI (P>0.05). This held true for the central response average (four degrees) as well as for the outer 6–25 degrees. In KII.1 only the peripheral amplitudes of Group B showed an influence due to refraction (P≤0.05). This may be due to adaptation as the recordings of group B were obtained in succession. As expected, significant differences were observed when the recordings obtained with the different systems were compared (P≤0.05). This revised version was published online in July 2006 with corrections to the Cover Date.     

多焦视网膜电图的研究进展及其临床应用

多焦电生理技术可在相对较短的时间内记录测试野内许多局部视网膜电图的反应波形,有助于了解视网膜或视路病变的机制,可用于一些眼病的早期诊断及预后,能客观和敏感地观察药物或手术的疗效。本文阐述目前多焦视网膜电图的记录和分析方法及其临床应用。     

Acute effects of cigarette smoking on multifocal electroretinogram

BACKGROUND: Cigarette smoking was shown to have stimulant effects on pattern visual-evoked potentials. The aim of this study was to investigate the acute effects of cigarette smoking on multifocal electroretinogram (mfERG). METHODS: This prospective case-control study was held in a tertiary referral centre in Turkish Armed Forces. mfERGs were investigated in a group of habitual smokers (30 right eyes of 30 subjects) in separate real smoking and sham smoking sessions. mfERG responses of the subjects were recorded after overnight abstinence. The responses were averaged over five retinal regions, the central hexagon (CH; central 6 degrees) and four concentric rings (ring 1 [R1; 7-12 degrees], ring 2 [R2; 13-18 degrees], ring 3 [R3; 19-24 degrees], ring 4 [R4; 25-30 degrees]). On each session mfERGs were recorded before (BS) and after smoking (AS) conditions. RESULTS: Regarding P1 amplitudes (first positive deflection of the mfERG) in the real smoking sessions, the differences were significant in the CH (BS: 66.2 +/- 16.3 microV, AS: 73.3 +/- 19.6 microV, P < 0.001), in R1 (BS: 44.3 +/- 13.0, AS: 48.3 +/- 16.0, P = 0.004) and in R2 (BS: 30.1 +/- 8.3, AS: 33.7 +/- 9.7, P = 0.002). Similar results were found for N1 amplitudes and P1 and N1 (first negative deflection of the mfERG) latencies in the CH, R1 and R2. The differences in outer retinal areas (R3, R4) in the real smoking sessions and in all rings in the sham smoking sessions were not significant. CONCLUSION: Cigarette smoking may stimulate the central retinal areas in the acute phase. This effect may be related with the stimulant effect of nicotine on neurotransmission, deleterious effects on retinal and/or choroidal circulation, carbon monoxide toxicity and nicotine withdrawal.