视网膜电图检测对视网膜静脉阻塞视功能的评价

目的 探讨视网膜电图（ｅｌｅｃｔｒｏｒｅｔｉｏｇｒａｍ,ＥＲＧ）的检测对视网膜静脉阻塞（ｒｅｔｉｎａｌ ｖｅｉｎ ｏｃｃｌｕｓｉｏｎ,ＲＶＯ）视功能评价的可能性。方法 对２１例ＲＶＯ患者及２３例正常对照组分别进行ＥＲＧ检测,测ａ、ｂ波振幅、峰潜时和振汤电位振幅。结果 ＲＶＯ组最大反应ａ、ｂ波振幅对照组明显下降,峰潜时延长、振荡电位幅值也明显降低,ＣＲＶＯ与ＢＲＶＯ组间有显著差异,说明随病变程度而加     

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。     

高血糖对实验性糖尿病大鼠视网膜电图的影响

目的观察糖尿病大鼠ERG和OPs的变化情况,探讨糖尿病对大鼠FERG和OPs的影响。方法将100只大鼠分为正常组10只和糖尿病组90只。糖尿病组用STZ造模,6个月后将符合条件的大鼠纳入观察组。检测6、9个月时大鼠ERG和OPs的表现。结果糖尿病大鼠视网膜电图a波、b波、OPs振幅有下降趋势,峰潜时延长,与对照组大鼠相比有差异(P<0.01);9个月时糖尿病大鼠a波、b波、OPs振幅降低,峰潜时延迟,与6个月时比较有显著差异(P<0.01或0.05)。结论高血糖可使糖尿病大鼠ERG和OPs振幅下降,峰潜时延长;且随病程的延长其影响逐渐增强。     

视网膜脱离眼的黄斑局部视网膜电图

目的：通过对视网膜脱离（retinal detachment,RD）眼的局部视网膜电图（local electroretinogram,LERG)记录分析,进一步了解RD眼黄斑部光感受器细胞与第二级神经元功能异常的情况,并对LERG与视功能预后的关系进行探讨。方法：120例RD患者128只眼的LERG被记录分析,应用手提眼底镜式局部刺激器通过放大的瞳孔直视眼底监控固视状况,记录a波、b波与OPs各项成分。结果：与对照组相比,LERG的a波、b波与OPs的异常率：在＜1周组分别为15%、15%与10%;在1-2周组为35%、45%与50%;在2-4周组为46.86%、56.25%与62.5%;在4-8周组为76%、84%与88%;在8周以上组则为86.96%、91.30%与95.56%。a波与b波在脱离时间＜1周组与对照组无明显差异;1-2周组a波与b波开始开始有明显降低（P＜0.05),随着发病时间的延迟,b波的下降较a波更为迅速,在2-4周则具有高度显著意义（P＜0.05)。b/a值在早期RP病变表现正常或轻度异常,伴随病程增加有降低趋势,在4-8周组即出现显著性降低（P＜0.05)。在眼底镜下黄斑部脱离的48只眼中,LERG各项成分的降低均有统计学意义;而在眼底镜下观测不到黄斑脱离的80只眼中,b波、OPs与OP2子波振幅也表现异常（P＜0.05)。结论：⑴在视网膜脱离眼,黄斑部光感受器与第二级神经元细胞的功能损害同时存在;⑵b波与a波的比值变化表明了内层与外层的相对损害程度,随着病情的发展,视网膜内层的损害有加重趋势;⑶RD伴黄斑脱离者的视网膜内外层功能受损程度明显增加,而镜下未脱离者也可存在功能的损害;⑷RD眼的OPs振幅可为视网膜内层循环功能的损害提供敏感性指标。研究认为：LERG对RD眼黄斑功能异常的客观定位诊断与视功能预后具有特定的临床意义。     

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)     

兔眼系列光视网膜电图振荡电位研究

用系列强度１３档刺激闪光记录３０例兔眼的视网膜电图和振荡电位，研究ＯＰｓ各子波的光强特性和参数特异性。结果表明，ＯＰｓ各子波振幅或峰时与刺激光强的函数关系为指数相关。其中，ＯＰ２峰时的相关性最高。不同对象间ＯＰｓ各子波振幅的变异系数较大，而峰时的变异系数较小。ＯＰｓ各子波的峰时改变比振幅发迹更为稳定，更具特异性。     

正常人闪光视网膜电图的特征

目的:探讨闪光视网膜电图(flash electroretinogram,F-ERG)在正常人的变化规律,以获得正常参考值.方法:应用法国Metrovision公司生产的Vision Monitor视觉诱发系统检测正常人53例73眼.F-ERG的5个标准反应,包括暗适应25dB弱光刺激时的反应(来自于视杆细胞)、暗适应odB强光刺激时的反应、振荡电位、明适应白色标准闪光刺激时的反应(来自于视锥细胞)和明适应快速重复闪烁光刺激的反应.按照10岁为一年龄组分成4组:20～29岁,20眼;30～39岁,22眼;40～49岁,19眼;50～60岁,12眼.比较4个年龄组振荡电位总振幅和a波、b波的振幅及潜伏期.结果:F-ERG暗适应25dB弱光刺激时a波无明显反应,b波潜伏期为1102±113ms,振幅为226.7±492μV;暗适应odB强光刺激时a波潜伏期为263±12ms,振幅为.205.4±40.1μV,b波潜伏期为49.3±2.3ms,振幅为481.2±81.2μV;明适应白色标准闪光刺激时a波潜伏期为23.0±1.6ms,振幅为-23.4±9.1μV,b波潜伏期为38.8±1.8ms,振幅为77.4±21.2μV;明适应快速重复闪烁光刺激b波的振幅为122.1±27.51μV;震荡电位总振幅为112.6±28.2μV.随着年龄的增加,振荡电位总振幅和其余4个标准反应的b波振幅逐渐降低,a波振幅与年龄的增加无明显相关性,50～60岁年龄组a、b波的潜伏期较其他组延长,但各年龄组两两比较无显著统计学差异(P＞0.05).结论:确定了正常人F-ERG的5个标准反应的正常值,并比较了振荡电位总振幅和a,b波振幅及潜伏期与年龄的关系,振荡电位总振幅和b波振幅随着年龄的增加逐渐降低,a波振幅与年龄的增加无明显相关性,50-60岁年龄组a,b波的潜伏期较其他组延长,但各年龄组两两比较无显著统计学差异(P＞0.05).     

Maturation of the electroretinogram of the neonatal rabbit

The development of the electroretinogram in the rabbit has been said to proceed with first the a-wave, then the b-wave and last the oscillatory potentials. The aim of our study was to reexamine this claim with special attention to the oscillatory potentials. Albino rabbits from the same litter were studied at weekly intervals for five weeks from the first week of life. A Grass photostimulator was used in light and dark adaptation and 50 amplified responses were averaged. Both 1–1000 Hz (electroretinogram) and 100–1000 Hz (oscillatory potential) band-widths were recorded simultaneously. The a-wave was the earliest signal to appear, at the second week of life. A rapid growth of the b-wave and oscillatory potentials was then noted between the second and third weeks, followed by a slower change. They evolved at the same rate, each with an increase in amplitude and decrease in peak time. The change in form of the b-wave was consistent with the sequential formation of each potential as the rabbit matured. The finding of simultaneous development of the b-wave and oscillatory potentials in the aging neonatal rabbit is contrary to previous reports.     

Oscillatory potentials of the electroretinogram in hypertensive patients with different antihypertensive treatment

Oscillatory potentials of the electroretinogram are useful to confirm the diagnosis of essential hypertension. Thirty-five hypertensive patients underwent primary antihypertensive therapy with four different treatments. Oscillatory potentials were recorded before the treatment and after 12 months. The oscillatory response increased in a statistically significant manner in the angiotensin-converting enzyme inhibitor group. This is probably caused by the vasodilatation mechanism, which increases the retinal blood flow.     

眼内麻醉剂对兔角膜内皮细胞影响的实验研究

目的:研究不同眼内麻醉剂对离体兔角膜内皮细胞的作用。方法:将实验用兔角膜取下后,分别用10g/L利多卡因、1g/L塞罗卡因及BSS处理。通过台盼蓝-茜素红联合染色观察兔角膜内皮细胞的形态学改变,并用计算机自动图像分析系统对兔角膜内皮细胞的损伤情况进行定量分析;对处理后的兔角膜内皮细胞进行扫描电镜观察,了解其超微形态学改变。结果:①各实验组中,10g/L利多卡因作用后兔角膜内皮细胞的损伤率分别为(0.91±0.12)%,(1.23±0.27)%,(2.42±0.31)%,(3.61±0.14)%;10g/L塞罗卡因作用后的兔角膜内皮细胞的损伤率分别为(0.68±0.16)%,(0.89±0.17)%,(1.84±0.34)%,(2.58±0.34)%。二者差异均具有显著性。(P<0.05,P<0.01)。②眼内麻醉剂的作用时间与兔角膜内皮细胞的损伤率呈正相关,相关系数分别为0.974、0.976。③眼内麻醉剂作用后,10g/L利多卡因造成的兔角膜内皮细胞的损伤情况较10g/L塞罗卡因更为严重。结论:10g/L利多卡因及10g/L塞罗卡因都会对兔角膜内皮细胞造成损伤。比较而言,不含防腐剂的塞罗卡因更安全。     

Effects of antibiotics on the in vitro ERG of the albino rabbit

This study describes the effects of penicillin G (PC-G) potassium, PC-G sodium, cloxacillin sodium (MCIPC), disodium sulbenicillin (SBPC), cefazolin sodium (CEZ) and cefsulodin sodium (CFS) on the in-vitro electroretinogram (ERG) of the albino rabbit.The b-wave and oscillatory potentials (OPs) were unchanged by 0.1 mM PC-G potassium or PC-G sodium. The OPs were slightly suppressed by 0.3 mM of either drug. While the a- and b-waves were not deteriorated, the OPs were greatly suppressed by 1.0 mM concentration. The effect of PC-G on the ERG was characterized by a selective suppression of the OPs. The b-wave and OPs were not suppressed by 0.03 mM MCIPC. They were slightly suppressed by 0.05 mM MCIPC. The a-wave, b-wave and OPs were not deteriorated by 1.0 mM SBPC. The b-wave and OPs were suppressed by 3.0 mM or 6.0 mM SBPC respectively. These changes appeared to be dose-dependent. Since the b-wave and OPs were concomitantly suppressed by both MCIPC and SBPC, these antibiotics, unlike PC-G, did not selectively suppress the OPs. The b-wave and OPs were unchanged by 0.1 mM CEZ or CFS. The OPs were slightly suppressed by 0.3mM CEZ or CFS. CEZ or CFS of 1.0 mM did not deteriorate the a- and b-waves, but selectively suppressed the OPs. The effects of CEZ and CFS on the ERG were characterized by a selective suppression of the OPs. The above-described changes in the ERG were reversible.     

F-ERG信号滤波及参数差异分析研究

目的：通过滤波技术,排除震荡电位干扰,准确测量闪光视网膜电图a波、b波的隐含期及振幅。
　　方法：对15例30眼门诊健康体检者行闪光视网膜电图检查,通频带为0.6~300 Hz和0.6~70 Hz时,分别测量a波、b波的隐含期及振幅,并进行对比分析,采用配对 t检验。
　　结果：将通频带设置为0.6~70Hz时,a波、b波表现为单峰,对比通频带为0.6~300 Hz时, a波、b波的隐含期延长,振幅下降(P<0.01)。
　　结论：将通频带设置为0.6~70 Hz时能获得光滑的a波、b波波形,能准确测量a波、b波的隐含期及振幅。     

Components of the electroretinogram: a reappraisal

During light adaptation a progressive increase in the intensity of a flash stimulus yields ERGs in which the a-wave shows a gradual reduction in peak time, while the b-wave appears to do the opposite. However, close inspection of the different ERG waveforms indicates that the wave identified as the b-wave for a threshold stimulus actually decreases in peak time with progressively stronger stimulus. Furthermore, what is identified as the b-wave for a threshold stimulus delivered in light adaptation will become a part of the a-wave complex if the same stimulus is used in dark adaptation. Data presented here indicate that the identification of the a- and b-waves of the ERG must be constantly revised according to the intensity of the stimulus and/or the level of retinal adaptation. These findings seriously challenge the validity of the a-b-wave nomenclature currently used in electroretinography. An alternative nomenclature, based on the first derivative (dv/dt) of the ERG wave, is proposed.     

The action of peptides on the mudpuppy electroretinogram (ERG)

Two neuropeptide substances were applied to the mudpuppy retina while the electroretinogram (ERG) was recorded. A low concentration of somatostatin (10(-9)M) was found to be a potent agent in increasing the amplitudes of all the oscillatory potentials (OPs) of the ERG. There was no appreciable change of the threshold sensitivity or the stimulus response curve of the b-wave. The highest concentration tested (10(-6)M) reduced the first OP to about the same amplitude as at the start of the experiment and attenuated the later OPs. A decrease of the suprathreshold b-wave was induced by the highest concentrations (10(-7), 10(-6)M) of somatostatin. A low concentration of substance P (10(-11)M) selectively and differentially decreased the earlier OPs (O1O2). Higher concentrations (10(-10), 10(-9)M) diminished the earlier OPs further, reduced the later OPs and decreased the supra-threshold a- and b-waves. The results support previous suggestions that the OPs reflect activities in feedback circuits initiated by the amacrines and indicate that somatostatin and substance P through separate mechanisms seem to interact with the inhibitory neuronal circuits which have been suggested to give rise to the OPs. Secondly, in agreement with previous work, the OPs appear to have a different origin from the b-wave. Thirdly, two separate classes of amacrines, each with a different transmitter, seem to be associated with different physiological roles.     

The effect of iodoacetic acid on the electroretinogram and oscillatory potentials in rabbits

It has been shown that a single injection of iodoacetic acid selectively (but temporarily) abolishes the b-wave of the electroretinogram. We examined whether such use of this chemical further substantiate our claim that the b-wave of the electroretinogram is a composite potential resulting from the summation (or integration) of faster retinal potentials, usually referred to as the oscillatory potentials. Full-field electroretinograms were recorded from adult New Zealand rabbits before and after a single, bolus injection of 15mg/kg of buffered iodoacetic acid. Both the 1–1000 Hz electroretinogram and the 100–1000 Hz oscillatory potentials were recorded simultaneously. The oscillatory potentials considered in this study were those normally seen on the rising phase of the b-wave. Following the intravenous injection of iodoacetic acid, there was a progressive decrease in the amplitude and peak time of the b-wave. This observation also was reflected in the oscillatory potential recordings, in which the long-latency oscillatory potentials (3 and 4) progressively disappeared while oscillatory potential 2 remained. We believe that these findings further support our contention that the oscillatory potentials are major components of the b-wave.     

The electroretinogram in Stargardt's disease and fundus flavimaculatus

A retrospective study was performed comparing the ERG results of 15 patients with Stargardt's disease and fundus flavimaculatus. Patients with fundus flavimaculatus had fish-tail lesions with or without macular changes, while the Stargardt's group had macular atrophy without fish-tail flecks. The mean visual acuity was 20/200 for the Stargardt's patients compared with a mean of 20/80 for the fundus flavimaculatus patients. The Stargardt's photopic and scotopic amplitudes were respectively 33% and 34% of normal, while the fundus flavimaculatus values were less impaired at 58% and 64% of normal.