视网膜电图明视负波反应在开角型青光眼中的临床应用价值

目的评价视网膜电图(electroretinogram,ERG)的明视负波反应(photopic negative response,PhNR)在开角型青光眼患者中的临床应用价值。方法应用美国ESPION视觉电生理仪及一次性使用的DTL微纤维电极测量67例(67眼)正常人(年龄为21~76岁)、41例(62眼)开角型青光眼患者(年龄为21~77岁)的PhNR。全视野刺激器由LED光源发光,选用蓝色背景光(亮度为10 cd/m2),刺激光为红色光(刺激光强度分别为1 cd.s/m2、5 cd.s/m2和7 cd.s/m2)。采用Humphrey C30-2程序检查患者的视野,根据视野检查结果将青光眼患者分为早期组12例(21眼),进展期组13例(17眼)和晚期组16例(24眼)。在记录视网膜电图时,患者的眼压控制在正常范围内。检查患者的眼底并测量视盘的杯盘比。结果正常人的明视ERG都有伴随b波的缓慢的负向电位,即PhNR,其振幅随年龄的增大而降低。青光眼患者的a波及b波的振幅和潜伏期与年龄匹配的正常值对照差异无显著性,但是PhNR振幅较正常值明显降低,甚至在视野敏感度轻度缺失的早期组患者就出现PhNR的振幅下降,并且随视野敏感度缺失的增加,进展期和晚期组患者PhNR的振幅下降更加明显。在全部青光眼患者中,PhNR的振幅与视野的平均偏差(mean deviation,MD)、模式标准差(pattern stan-dard deviation,PSD)和垂直方向的杯盘比(C/D)存在明显的相关性(P<0.01)。结论开角型青光眼患者的PhNR的振幅比正常对照组低,PhNR振幅降低与青光眼病情的严重程度相关,早期青光眼患者的PhNR振幅就出现下降,并随视野敏感度缺失的增加下降更加明显。PhNR振幅降低对青光眼有较高的敏感性和特异性。PhNR可以作为开角型青光眼的早期检测及其青光眼损伤进展的一个视功能评价指标。     

视网膜电图明视负波反应在检测原发性开角型青光眼中的应用

目的 探讨视网膜电图( Electroretinogram,ERG)明视负波反应(Photopic Negative Response,PhNR)在检测原发性开角型青光眼(Primary Open angle Glaucoma,POAG)中的应用.方法 应用德国罗兰视觉电生理仪测量52例(67只眼)正常人及137例(173只眼)POAG患者的a波振幅、b波振幅、PhNR振幅和潜时.全视野刺激器由LED光源发光,选用白色背景光和白色刺激光.采用HumphreyC24-2程序检查患者视野的平均缺失(Mean Deviation,MD)和(Pattern Standard Deviation,PSD),并根据视野检查结果将POAG患者分为早期组55例(62只眼),进展期组40例(60只眼)和晚期组42例(51只眼).应用频域OCT (Cirrus OCT)检测全部POAG患者的平均视网膜神经纤维层(mean retinal nerve fiber layer,mRNFL)厚度.结果 四组中a波振幅、b波振幅、PhNR潜时、PhNR振幅的差异均具有统计学意义(P＜0.05).a波振幅、b波振幅、PhNR潜时的变异程度较大.MD、mRNFL与PhNR振幅均呈正的直线关系(P=0.000),相关系数分别为0.59、0.45.PSD与PhNR振幅呈负的直线关系(P =0.016)相关系数为-0.37.a波、b波振幅、PhNR振幅的ROC曲线下面积分别为0.853、0.830和0.918.其中,PhNR振幅的诊断价值较高.在设定特异性≥95％的情况下,其敏感性分别为60.4％、54.2％和85.4％.结论 POAG组PhNR振幅和潜时较正常对照组明显降低和延迟;PhNR振幅降低与青光眼病变的严重程度相关;PhNR振幅在POAG早期诊断方面具有较高的敏感性,因此PhNR可以作为一个评价POAG视功能的有用指标.     

蓝／黄视野与视网膜电图明视负波反应在原发性开角型青光眼早期诊断中的应用

目的 探讨蓝/黄视野检查(B/YP)和视网膜电图(ERG)明视负波反应(PhNR)在原发性开角型青光眼早期诊断中的应用价值.方法 选择20例常规白白视野检查(W/WP)正常,眼底视乳头检查C/D≥0.5,眼压>21mm Hg的可疑青光眼(SG)患者,20例正常对照者进行B/YP检查和PhNR检查.采用OCTOPUS101全自动视野计G2程序进行B/YP检查,采用重庆爱达VETS-4000 AD视觉电生理仪进行闪光视网膜电图明视负波反应检测.结果 正常对照组和SG组的明视ERG都有伴随h波的缓慢的负向电位,即PKNR,SG患者的a波和b波的振幅和潜伏期与对照组差异无显著性,而PhNR振幅20例中有15例出现较正常降低;B/YP检查在SG组中,有11例出现异常.PhNR振幅与B/YP异常的视野平均缺损(MD)有明显的相关性(P<0.01)结论 B/YP检查能发现W/WP尚不能检出的视野缺损,PhNR振幅的降低对青光眼有较高的敏感性,两者联合应用对原发性开角型青光眼的早期诊断有较高的敏感性.     

The negative response of the flash electroretinogram in glaucoma

The existence of a negative ERG component following the b-wave has been known for a long time. Recently, in unilateral macaque experimental glaucoma, a negative response in flash electroretinograms under scotopic as well as photopic conditions has been shown to be greatly reduced or absent compared to the healthy fellow eye. The aim of this pilot study was to test whether a late negative electroretinogram component is reduced also in human glaucoma patients under different stimulus conditions. Dark-adapted ganzfeld flash electroretinograms were recorded after 30 min of dark using two test conditions, obtained as optimal in pilot studies on controls. Under the scotopic condition I white Xenon-flashes of intensity 0.53 Log photopic Td s were presented on a low white background of 1.38 Log scotopic Td. Under the more photopic condition II orange flashes of intensity –0.37 Log photopic Td s were presented on a blue-adapting background of 2.5 Log scotopic Td. Nine controls and 18 patients with advanced glaucoma were analyzed. The amplitude of the negative response was not significantly reduced in glaucoma patients (condition I: –28.5±23.7 V; condition II: –25.2±19.7 V) compared to controls (condition I: –41.4±36.6 V; condition II: –31.3±26.2 V). The peak latency of the responses under condition I and II did not differ significantly between patients and controls. Thus, the late negative electroretinogram component in ganzfeld flash electroretinograms obtained under scotopic and more photopic conditions does not seem to distinguish as easy between human controls and glaucoma patients as animal experiments suggest.     

The photopic negative response of the flash electroretinogram in retinal vein occlusion

The photopic negative response (PhNR) has recently been shown to be severely affected in central retinal artery occlusion (CRAO), despite relative preservation of the cone b-wave compared to that in the healthy unaffected fellow eye. The aim of this study was to test how the PhNR of the flash electroretinogram (ERG) is affected in human retinal vein occlusion. PhNR was elicited with red stimuli (1 cd s/m², 5 cd s/m², and 7 cd s/m² with 4 ms duration) and blue background (10 cd/m²). Standard Ganzfeld flash ERG was produced according to the ISCEV standard for the clinical electroretinogram (2004). Sixteen patients with central retinal vein occlusion (CRVO), 14 patients with branch retinal vein occlusion (BRVO), and 16 controls were analyzed. The amplitude of the PhNRs was significantly smaller in the CRVO and BRVO eyes than those in the unaffected fellow or control eyes (p = 0.000). There was a significantly greater reduction of PhNR amplitudes than that of other waves including the OPs, rod b-wave, combined a-wave and b-wave, cone a-wave and b-wave, and 30 Hz flicker ERG. Thus, PhNR amplitude in retinal vein occlusion is severely affected. There is a potential role for PhNR in assessing inner retinal damage and evaluating the effect of treatment.     

视网膜电图明视负向反应对外伤性视神经萎缩的诊断意义

目的研究外伤性视神经萎缩的视网膜电图（ERG）各成分及其明视负向反应（PhNR）的变化特点，并进行PhNR与视网膜神经纤维层厚度（RNFLT）、视野平均缺损值（MD），以及杯盘比（C／D）的相关性研究，探索在外伤性视神经萎缩中PhNR的变化规律。方法选取外伤性视神经萎缩的患者21例（25眼）和与其性别年龄相匹配的正常人25例（25眼）。分别对两组进行ERG、视野、眼底照相和光学相干断层扫描（OCT）检查，比较两组视网膜电图，并将外伤性视神经萎缩组的PhNR振幅分别与MD、C／D和RNFLT进行相关性分析。结果外伤性视神经萎缩组的PhNR振幅比对照组明显下降（P〈0．01），而外伤性视神经萎缩组和对照组的ERG中暗视反应、最大反应、30Hz震荡电位的振幅差异无统计学意义，视神经萎缩组明视反应a波和b波振幅差异也无统计学意义。PhNR的振幅与视神经损伤情况如RNFLT（r=0．665）、MD（r=0．564）、杯盘比（r=0．686）等相关，且相关关系有统计学意义（P〈0．01）。结论视网膜电图PhNR振幅在外伤性视神经萎缩眼明显地下降甚至消失，PhNR可作为外伤性视神经萎缩的诊断和神经节细胞及其轴突功能评价的良好指标。     

The photopic negative response of the macaque electroretinogram: reduction by experimental glaucoma

PURPOSE: To investigate the photopic flash electroretinograms (ERGs) of macaque monkeys in which visual field defects developed as a consequence of experimental glaucoma. METHODS: Unilateral experimental glaucoma was induced in 10 monkeys by argon laser treatment of the trabecular meshwork. Visual field sensitivity was assessed behaviorally by static perimetry. Photopic ERGs were recorded to brief- (< or = 5 msec) and long-duration (200 msec) red ganzfeld flashes on a rod-suppressing blue-adapting background. Electroretinograms were recorded in four other monkeys, after intravitreal injection of tetrodotoxin (TTX; 3.8-8 p.M) to suppress action potentials of retinal ganglion and amacrine cells, and in six normal adult human subjects. RESULTS: Experimental glaucoma removed a cornea-negative response, the photopic-negative response (PhNR), from the ERG. The PhNR in control eyes was maximal approximately 60 msec after a brief flash, 100 msec after onset, and 115 msec after offset of the long-duration stimulus. The PhNR in experimental eyes was greatly reduced when the mean deviation of the visual field sensitivity was as little as -6 dB. As visual sensitivity declined further, the PhNR was reduced only slightly more. The a- and b-waves were unchanged, even when sensitivity decreased by more than 16 dB. Tetrodotoxin also selectively reduced the PhNR. The PhNR was observed in normal human ERGs. CONCLUSIONS: The cornea-negative PhNR of the photopic ERG depends on spiking activity and is reduced in experimental glaucoma when visual sensitivity losses are still mild. The PhNR most likely arises from retinal ganglion cells and their axons, but its slow timing raises the possibility that it could be mediated by glia. Regardless of the mechanism of its generation, the PhNR holds promise as an indicator of retinal function in early glaucomatous optic neuropathy.     

The relationship between stimulus intensity and response amplitude for the photopic negative response of the flash electroretinogram

The aim of this study was to investigate the relationship between stimulus intensity and response amplitude for the photopic negative response (PhNR) of the flash ERG. Specific aims were (i) to determine whether a generalized Naka–Rushton function provided a good fit to the intensity–response data and (ii) to determine the variability of the parameters of the best-fitting Naka–Rushton models. Electroretinograms were recorded in 18 participants, on two occasions, using both DTL fibre and skin active electrodes, in response to Ganzfeld red stimuli (Lee filter “terry red”) ranging in stimulus strength from −1.30 to 0.53 log cd.s.m⁻² (0.28–2.11 log phot td.s) presented over a steady blue background (Schott glass filter BG28; 3.9 log scot td). PhNR amplitude was measured from b-wave peak and from pre-stimulus baseline. The Naka–Rushton function was fitted to all intensity–response data, and parameters, ‘n’, ‘Vmax’ and ‘K’ were obtained. Coefficients of variation (CoV), and inter-ocular and inter-session limits of agreement (LoA) were calculated for both Naka–Rushton parameters. A generalized Naka–Rushton function was found to provide a good fit to the intensity–response data, except at the highest stimulus intensity, where a reduction in amplitude occurred in many individuals. The ‘Vmax’ parameter was less variable than ‘K’ for all intensity–response data. Variability was lower for DTL than skin electrodes, and for peak-to-trough PhNR measurements, compared to baseline-to-trough. This study has demonstrated for the first time that the Naka–Rushton model provides a useful means of quantifying the intensity–response relationship of the PhNR.     

早期开角型青光眼患者多焦视网膜电图的研究

目的探讨早期开角型青光眼(POAG)患者多焦视网膜电图(mfERG)的改变和在视网膜不同象限及六个环的分布特性。方法对早期POAG36例(36只眼),正常对照组40例(40只眼)行mfERG检测,记录不同视野区域和6个环的一阶、二阶反应N1波、P1波的振幅密度和潜时,并与正常对照者进行比较。结果一阶反应鼻上(SN)、鼻下(IN)、颞下(IT)、颞上(ST)4个象限N1、P1波的振幅密度值与潜时,两组之间均无显著差异。二阶反应鼻上(SN)、颞下(IT)、颞上(ST)P1波的振幅密度值,青光眼组显著降低(P<0.05)。随偏心度增大,两组mfERG一阶反应、二阶反应P1波、N1波振幅密度逐渐减小,青光眼组与对照组振幅密度的差值在5环(视野周边)较大,在1和2环(视野中央)较小。青光眼组患者的mfERG指标与视力无线性相关关系。结论早期POAG患者mfERG有明显改变,证实了POAG患者早期视神经损害的特点,为早期POAG的诊断提供有效的依据。     

原发性开角型青光眼患者的多焦视网膜电图研究现状

原发性开角型青光眼是一种慢性进行性视神经病变,可以导致严重的视力损害,是眼科重要的致盲性眼病。多焦视网膜电图是一种最新的测量整个视野中许多细小部位视网膜电图的检测方法,能够非常准确、快速地反映某一局部的视网膜功能,对于原发性开角型青光眼患者的早期诊断具有极其重要的价值。本文依据相关文献,对多焦视网膜电图在原发性开角型青光眼诊断中的研究现状进行综述。     

视网膜电图明视负向反应研究进展

视网膜电图（ERG）的明视负向反应（PhNR）是在明适应条件下用亮光刺激时在正向b波后记录到的一负向电位。灵长类动物实验研究及临床研究证实,PhNR的产生与视网膜神经节细胞（RGCs）及其轴突有关,而研究啮齿类动物发现,PhNR起源于无长突细胞的电活动。就灵长类动物PhNR记录条件的改进、不同记录条件下其波形特点、啮齿类动物PhNR的记录条件及特点,以及局部视网膜PhNR在临床应用中的新进展进行综述。     

正常人视网膜电图明视负波反应的研究

目的 建立国人正常人视网膜电图明视负波反应(Photopic negative response,PhNR)的振幅和潜伏期的正常值,探讨其PhNR振幅和潜伏期的变异程度和与年龄、性别、眼别的关系.方法 应用ROLAND生产的视觉电生理仪测量正常人150名(150只眼)在蓝-红和白-白两种刺激下的PhNR潜伏期和振幅.分别按间断年龄20岁进行分组和性别统计其正常值范围并进行比较,用Spss17.0对数据进行统计学处理.结果 蓝-红和白-白PhNR潜伏期在四个年龄组之间差异无统计学意义(P=0.348);而蓝-红PhNR振幅在四个年龄组之间差异有显著性(P =0.007),但白-白PhNR振幅在四个年龄组之间差异无统计学意义(P =0.077).在各年龄组PhNR潜伏期和振幅的变异系数中,＜20岁的PhNR潜伏期和振幅变异系数最小,20～ 40岁的PhNR潜伏期和振幅变异系数最大.在两种刺激下,PhNR潜伏期与年龄无直线相关关系(P =0.210,0.646);而PhNR振幅与年龄呈负的直线相关关系(P =0.007,0.006).PhNR潜伏期和振幅在左右眼之间的差异无统计学意义(P＞0.05),其在男女之间的差异也无显著性(P＞0.05).结论 在蓝-红和白-白两种刺激下PhNR潜伏期和振幅不受性别和眼别的影响;但PhNR振幅受年龄的影响,随着年龄的增长而下降.在进行PhNR检查时,应综合考虑上述因素的影响.     

正常眼视网膜电图明视负向反应研究

目的研究不同性别、年龄正常眼的视网膜电图（electroretinogram，ERG）中明视负向反应（photopic negative response，PhNR）的潜伏期和振幅，并分析性别、年龄对PhNR的影响。方法选取正常健康者和单眼外伤者共54例（60眼），进行ERG检查，记录其视网膜电图PhNR的潜伏期和振幅，分别按年龄（〈20岁组，20-40岁组，〉140岁组）和性别统计其正常值范围并进行比较。结果PhNR潜伏期女性较男性略短，PhNR振幅女性较男性略低，但差异无显著性（P〉0.05）。随年龄增大，PhNR的潜伏期延长，各组间差异均有显著性（P〈0．01）；随年龄增大，PhNR的振幅下降，差异出现在40岁以上组与其他两组之间（P=0．02）。结论与其他ERG成分类似，PhNR的潜伏期和振幅亦受年龄和性别的影响，故在进行视网膜电图PhNR分析时应综合考虑性别、年龄等因素。     

图形视网膜电图检测原发性开角型青光眼视网膜功能的意义

目的 观察原发性开角型青光眼图形视网膜电图的改变及其特点,了解ＰＥＲＧ在检测ＰＯＡＧＰＹ视网膜功能方面的意义。方法 对３６例（５９只眼）ＰＯＡＧ及３２例（５９只眼）年龄相匹配的正常人进行ＰＥＢＧ检测。结果 ＰＯＡＧ患者ＰＥＲＧ的ＡＰ１、ＡＮ２、ＡＮ１、ＡＮ２／ＡＰ１下降;运用ＡＮ２＋ＡＰ１〈２．７及ＡＮ２／ＡＰ１下降;运用ＡＮ２＋ＡＰ１〈２．７及ＡＮ２／ＡＰ１〈０．７的方法,对已确认的ＰＯＡＧ进行     

The photopic negative response of flash ERG in nonproliferative diabetic retinopathy

Purpose To evaluate with electrophysiological responses and Optical Coherence Tomography (OCT), the short term functional and structural effects at the macula following intravitreal injection of bevacizumab for macular edema. Methods Prospective, non-randomized, interventional case study. In total, 17 eyes of 17 patients with macular edema due to vein occlusions and diabetic retinopathy received intravitreal bevacizumab. All Patients underwent complete ophthalmic examination including Snellen visual acuity testing, Multifocal Electroretinography (mfERG) and Full Field Electroretinography (FERG), OCT scanning at baseline at 1 week and 2 months after intravitreal bevacizumab. Results FERG did not show any change in waveform parameters following intravitreal injection of bevacizumab. Average mfERG macular responses within central 20° showed increased P₁ amplitude (P < 0.05) at 2 months after treatment as compared to the baseline recordings in all subjects. No changes were seen in the implicit time. There was 22% improvement in central retinal thickness (CRT) at 2 months compared to the baseline (P < 001). Conclusion Intravitreal injection bevacizumab resulted in reduction in the central retinal thickness and mild to moderate improvement in the mfERG amplitudes in this short-term study. The visual acuity changes did not directly correlate with the reduced central retinal thickness or improvement in mfERG. The short-term results showed no serious ocular adverse effects. Therefore on short-term follow up the off label drug showed improvement of macular edema secondary to vein occlusion and diabetic retinopathy with no demonstrable toxic effects.     

明视负波反应在青光眼早期诊断中的临床意义

视网膜电图的明视负波反应(PhNR)是在明适应条件下,用亮光刺激时,在正向b波后记录到缓慢的负向电位,但当用色光作背景和色光作为刺激光时,PhNR反应明显增大。动物实验证实PhNR产生于视网膜神经节细胞及其轴突,在实验性青光眼的视野轻度缺失时出现PhNR振幅下降。PhNR可以在开角型青光眼患者中呈特征性的振幅降低,并在可疑开角型青光眼中表现PhNR振幅降低。提示PhNR可以作为早期开角型青光眼损伤或者其青光眼损伤进展的一个视功能评价指标。     

The effect of broadband and monochromatic stimuli on the photopic negative response of the electroretinogram in normal subjects and in open-angle glaucoma patients

The aim was to investigate the effects of monochromatic and broadband stimuli on the amplitude of the photopic negative response (PhNR) and to compare the sensitivities of these stimuli for the detection of ganglion cell damage in glaucoma patients. Forty-one healthy subjects were studied, along with 16 patients with open-angle glaucoma. Photopic electroretinograms (ERGs) were elicited with monochromatic red, amber, green, and broadband white stimuli of progressively brighter intensities in a blue background. Pattern ERGs were also recorded using a 0.8° checkerboard pattern on a 21.6° × 27.8° screen. In the photopic ERGs of the control subjects, the PhNR amplitude was significantly higher (P < 0.01) to red than to monochromatic amber, green, and broadband white stimuli of the same intensity. In glaucoma patients, the percentage of amplitude reduction was greater for the PhNR to red (68%, P < 0.001) than to the broadband stimulus (38%, P = 0.001). The PhNR to red monochromatic stimulus appeared to be a more sensitive parameter, with a larger area enclosed by the receiver-operating characteristic curve (0.97) than for the PhNR to broadband stimulus (0.76). Also, the PhNR to red stimulus showed a more significant correlation with the pattern ERG and the visual field defects (P < 0.05) than the PhNR elicited with broadband stimulus. These findings suggest that ganglion cell activity can be more efficiently evaluated with the PhNR elicited with a red than with a broadband stimulus. The PhNR thus appears to be a promising test for the diagnostics of the ganglion cell dysfunction.