多焦视诱发电位在屈光不正性弱视眼视功能检查中的应用

本文用多焦视诱发电位研究屈光不正性弱视眼在视野不同离心度的视功能变化。刺激图形由６１个小六边形组成。刺激野直径约１３．６度。在电脑程序控制下,各六边形同时并互相独立地进行刺激,自动分离提取到各自的反应波形。屈光不正性弱视眼与正常对照眼比较,在刺激图形中心区潜伏期延长,振幅下降,差异有显著性。本研究证实,屈光不正性弱视眼视野中心区视功能下降比周边区显著     

Multifocal Visual Evoked Potential (mfVEP) and Pattern-Reversal Visual Evoked Potential Changes in Patients with Visual Pathway Disorders: A Case Series

Abstract

The purpose of this study was to evaluate multifocal visual evoked potential (mfVEP) and pattern-reversal visual evoked potential (PVEP) changes in patients with pathology at various levels of the visual pathway determined by other methods. Six patients with different visual pathway disorders, including vascular ischaemic events and compressive optic neuropathy, were reviewed. All patients were tested with both mfVEP and full-field and half-field PVEPs. Results were assessed in relation to other diagnostic tests such as magnetic resonance imaging, Humphrey visual field test, and optical coherence topography. The cases in this study demonstrate a potential higher sensitivity of mfVEP compared with conventional PVEPs in detecting lesions affecting the peripheral field, horizontal hemifields, and lesions of the post-chiasmal pathway. The limitation of the PVEP in this setting is probably due to phase cancellation and overrepresentation of the macular region. mfVEP provides a more accurate assessment of visual defects when compared with conventional PVEP. The independent assessment of different areas of the visual field improves the detection and localization of lesions and provides an objective topographical map that can be used in clinical practice as an adjunct to other diagnostic tests and to assess disease progression.     

Multifocal Visual Evoked Potential (mfVEP) and Pattern-Reversal Visual Evoked Potential Changes in Patients with Visual Pathway Disorders: A Case Series

The purpose of this study was to evaluate multifocal visual evoked potential (mfVEP) and pattern-reversal visual evoked potential (PVEP) changes in patients with pathology at various levels of the visual pathway determined by other methods. Six patients with different visual pathway disorders, including vascular ischaemic events and compressive optic neuropathy, were reviewed. All patients were tested with both mfVEP and full-field and half-field PVEPs. Results were assessed in relation to other diagnostic tests such as magnetic resonance imaging, Humphrey visual field test, and optical coherence topography. The cases in this study demonstrate a potential higher sensitivity of mfVEP compared with conventional PVEPs in detecting lesions affecting the peripheral field, horizontal hemifields, and lesions of the post-chiasmal pathway. The limitation of the PVEP in this setting is probably due to phase cancellation and overrepresentation of the macular region. mfVEP provides a more accurate assessment of visual defects when compared with conventional PVEP. The independent assessment of different areas of the visual field improves the detection and localization of lesions and provides an objective topographical map that can be used in clinical practice as an adjunct to other diagnostic tests and to assess disease progression.     

左旋多巴对弱视眼视诱发电位影响的研究

目的:探讨左旋多巴治疗弱视的效果。方法:正常眼和弱视眼服用单次剂量左旋多巴前后进行图形视诱发电位(pattem visual evoked poten-tial,PVEP)检测。结果:正常眼服药后中空间频率PVEP的N_1P_1振幅和高空间频率PVEP的P_1N_2振幅增大,弱视眼服药后低空间频率PVEP的N_1波潜伏期和中空间频率PVEP的P_1波潜伏期缩短。结论:左旋多巴可改善弱视眼的视功能,可作为弱视的一种新的治疗方法。眼科学报1997;13:182—185。     

单眼弱视与双眼弱视病儿视觉诱发电位的分析

分别对单眼弱视和双眼弱视两组病儿进行了图形反转视觉诱发电位及白光、红光、蓝光闪光视诱发电位P100波的观察,结果表明单眼弱视与双眼弱视的发病机制不同。     

视网膜色素变性的多焦视诱发电位及其与视野的比较

目的:探讨视网膜色素变性(retinitispigmentosa,RP)的多焦视诱发电位(multifocalvisualevokedpotential,mfVEP)特性及评价mfVEP作为RP客观视野检测方法的可能性。方法:检测12例(19只眼)RP患者和15例(30只眼)正常人的mfVEP,刺激野为带图形的含60个小块的飞镖盘,单侧对应视角为26°。比较RP患者与正常人mfVEP的二阶函数核第一片的P1波的振幅。对RP患者还进行30°阈值视野检测,检验对应区域mfVEP的P1波振幅总和与视野光敏感度总和的相关性。结果:与正常人相比,RP患者各环的mfVEP的P1振幅总和的降低均有显著意义(P<0.05)。除了下1环和下2环外,其余各环mfVEP的P1振幅总和与视野光敏感度总和均有显著相关(P<0.05)。结论:mfVEP与视野间存在着一定的相关性,mfVEP可作为评价RP患者视功能的客观方法。     

用视诱发电位和富里叶变换作视力客观估计

目的:研究用图形视觉诱发电位(PVEP)和离散富里叶变换(DFT)作视力客观估计的方法。方法:检测对象为33只正常眼。用翻转频率为10次/秒,条纹张角分别为30、20、18、12、10、6、4和2弧分的垂直方波光栅图形刺激,记录相应的稳态图形视诱发电位。用离散富里叶交换提取WEP频谱中10Hz成分的幅值。以光栅条纹张角为横坐标、相应的VEP频谱幅值为纵坐标作关系曲线,取阈值附近的近似线性部分的数据点作直线回归,用外推法求得阈值和视力。结果:比较VEP所测之视力与用国际标准视力表所测之视力,可见在本研究中70％的受检眼VEP视力估计较准确。结论:用本研究中的VEP技术客观地测量视力可靠性较高。眼科学报1997;13:59～61。     

Multifocal VEP Difference between Early- and Late-onset Strabismus Amblyopia

Purpose: To measure and compare the multifocal visual evoked potentials (mfVEP) difference between early- and late-onset strabismus amblyopia. Methods: Eleven patients with early- and 11 with late-onset strabismus amblyopia with similar range of visual acuity and 11 normal control subjects were recorded with mfVEP. Results: There was no significant difference in latency or amplitude between amblyopic and fellow eyes for the early-onset amblyopic group, whereas in the late-onset amblyopic group, latencies were significantly prolonged and amplitudes were attenuated in the central region of visual field in the amblyopic eye. The responses in the central region of visual field in both amblyopic and fellow eyes of the early-onset amblyopic group were of longer latency and smaller amplitude than normal. In the late-onset group, the responses from amblyopic eye were of increased latency and decreased amplitude in the central visual field compared with normal, but either latency or amplitude from fellow eye did not differ from normal significantly. Conclusions: There is significant difference in the mfVEP characteristics of patients with early- and late-onset strabismus amblyopia.     

屈光参差性弱视mfVEP的临床分析

目的分析屈光参差性弱视患者多焦视觉诱发电位(mfVEP)的特征性变化,以探讨弱视发病的可能机制。方法采用VERISScienceTM4.2多焦电生理系统对23例屈光参差性弱视患者、30例正常人进行双眼图形mfVEP检查,以潜伏期与振幅为分析指标,进行了屈光参差性弱视眼、对侧眼和正常对照三组mfVEP的对比研究。结果在六个离心度上弱视眼反应振幅密度较其对侧眼和正常眼均显著降低,潜伏期延长。弱视眼波形异常程度随离心度增加而减小,在六个离心度上弱视眼mfVEP的波形异常程度都与弱视眼的视力异常程度有相关性。结论屈光参差性弱视患者的mfVEP具有明显的特征性改变,表明弱视患者的视觉传导通路存在明显损害,在中心区损害重于周边区,弱视眼波形异常程度与视力异常程度有明显的相关性,mfVEP检查对于弱视的诊断、治疗和预后判断具有一定的指导意义。     

多焦视觉诱发电位及其在青光眼中的应用

多焦视觉诱发电位(mVEP)近来在青光眼中多有介绍。较之传统的VEP，它具有更佳的空间定位能力，同时，相对于主观视野检查，因为没有学习曲线，更容易让患接受。本就mVEP的记录方法，正常人的mVEP及其在青光眼中的应用，特别是它与主观视野的关系作一综述。     

多焦视诱发电位在青光眼视野损害检测中的应用

目的了解多焦视诱发电位(mfVEP)在青光眼视野损害检测中的作用。设计病例对照研究。研究对象 20例正常人和20例原发性青光眼患者。方法对20例正常人和20例原发性青光眼患者应用RETIscan mfVEP记录系统3．20行检查, 分别测量所有受试者mfVEP每一位点记录曲线的振幅,并计算受试者的双眼视网膜反应不对称系数(RAC)。比较青光眼患者 mfVEP检查的暗点与OCTOPUS 101型自动视野计G2程序检查的视野缺损区的对应性。主要指标振幅、RAC。结果在与自动视野计检查发现的视野缺损相对应的部位,90％患眼的mfVEP表现为至少3个相邻位点的振幅降低或RAC超出正常人数据库均数的2倍标准差(SD)。其中63％患眼表现为至少3个相邻位点的振幅降低超出正常人均数的2 SD,70％患眼表现为至少3个相邻位点的RAC超出正常人均数的2 SD。有2例患者(2眼)的自动视野计检查结果正常,但mfVEP显示有视野异常。正常人中无一眼的mfVEP表现为视野异常。结论 mfVEP有可能作为青光眼视野损害的客观检查手段。     

多焦视觉诱发电位诊断青光眼的价值

目的:记录正常人和青光眼患者的多焦视觉诱发电位(multifocalvisualevokedpotential,mfVEP),评价mfVEP在青光眼诊断及病情监测中的价值。方法:采用法国VisionMonitor多焦视觉电生理仪的二阶kernel技术检测21例32只正常对照眼、37例58只原发性青光眼的mfVEP,比较同一个体双眼间的振幅均方根(rootmeansquare,RMS),并分析原发性青光眼患者的mfVEP与Humphrey视野(Humphreyvisualfield,HVF)的相关性。结果:正常人RMS值与年龄、眼别无关,但女性RMS值大于男性,差异有显著性意义(P<0.05);正常眼mfVEP的RMS值个体间变异大(变异系数CV=43.05%),但同一个体双眼间反应差异不大;双眼损害程度相近的青光眼,双眼mfVEP的RMS值无明显差异(P=0.251);双眼损害程度不一的青光眼,双眼RMS值不同(P=0.024);mfVEP的RMS值总和与视野的平均缺损值(meandefect,MD)具有较强的相关性(rs=-0.487,P=0.000)。结论:正常人mfVEP个体间变异性大,但同一个体双眼间反应差异不大。对于青光眼双眼损害程度不一或单眼损害者,进行双眼间mfVEP非对称分析,可以早期发现青光眼损害并进行病情监测。青光眼患者的mfVEP振幅与视野平均缺损值相关性较好,在一定程度上可以弥补主观视野检查的不足。     

Evoked Potential and Preferential Looking Estimates of Visual Acuity in Pediatric Patients

Pattern visual evoked potentials (VEPs) and behavioral visual acuity measured with forced-choice preferential looking techniques (FPL) were obtained from 172 pediatric patients between the ages of 4 months and 10 years. More children younger than 2 years of age successfully completed monocular testing by pattern VEP than by FPL methods. For children older than 2 years, we were equally successful in completing each of the two tests. Of those children who completed both tests, the VEP results agreed with Snellen, Allen, and “E” acuity measures more often (66%) than did the FPL results (50%). Both tests were more sensitive than Allen single characters in detecting interocular acuity differences in children younger than 3 years of age.     

多焦视诱发电位地形图

目的阐明多焦视诱发电位成分是如何从多通道双极记录中得出和进行地形学分析的.并研究不同的视皮层记录位置对多焦视诱发电位的波形、潜伏期(ms)和振幅(mV)的影响.方法采用多通道罗兰电生理系统(Retiscan,Wiesbaden/Brandenburg,Germany)分别测量50位正常人双眼不同视野的多焦视诱发电位(visual evoked potential,VEP)(最大的离心率为30°).两眼分别给予刺激.伪随机改变的刺激由多通道罗兰系统产生.刺激图形由60个刺激扇形组成,每个扇形又含16个方格,8个白色方格(＞130 cd/m2)和8个黑色方格(＜2 cd/m2).各个刺激单元的刺激翻转由一个伪随机序列控制.电极放置参照双极枕叶电极放置法,同时从4个前-后矢状中线及4个水平连线(横贯枕叶视皮层)上的皮肤电极上记录视觉诱发电位波形.上述电极可以是正极或负极.结果在记录的枕叶皮层区,不同记录通道所记录的VEP显示了不同的平均峰潜伏期和振幅值.在矢状中线上记录到的mVEP,其最大振幅值小于水平线上的记录值.另外,刺激视网膜不同部位所诱发的电位在头皮的位置是不同的.结论双极枕叶电极在矢状中线上记录到的mVEP与视野地形图记录的有良好的相关性.双极记录位置负极在枕骨粗隆,而正极在枕骨粗隆矢状轴上2 cm或4cm或正极在枕骨粗隆水平左、右4 cm时,记录得到的VEP结果更具可比性.为了更准确地评估客观视野缺损,可进行上下1/2或者水平1/2的多焦VEP记录.     

Changes in the Binocular Fixation Patterns and the Visually Evoked Potential in the Treatment of Esotropia with Amblyopia

Using the binocular fixation pattern (BFP) and the visually evoked potential (VEP), thirteen amblyopic patients with comitant, non-accommodative esotropia with an angle range up to 30Δ were studied before and during occlusion therapy. A graded BFP with a stronger preferred fixation could be used to diagnose amblyopia. The BFP, however, showed no significant change with therapy despite improvement in acuity. In contrast, the VEP amplitudes, initially reduced in amblyopia, increased significantly as the vision responded to patching. The VEP was useful in diagnosing strabismic amblyopia and giving a predictive range of acuities.     

斜视性弱视儿童多焦视觉诱发电位的研究

目的:研究斜视性弱视多焦视觉诱发电位特征,探讨弱视发病机制。方法:采用德国Roland公司的RETIscan3.15多焦视觉电生理仪,记录和分析了斜视性弱视儿童80眼,外斜43眼内斜37眼,并与正常对照组儿童60眼作比较。结果:弱视眼N1-P1波振幅密度平均值和P1-N2波振幅平均值较正常组儿童在中央视野有下降,随离心度增加,这种现象呈下降趋势。P1波潜伏期平均值无明显异常。正常组和各斜视性弱视组N1-P1波振幅密度平均值:颞侧<鼻侧,P1波潜伏期平均值:颞侧>鼻侧。结论:斜视性弱视mfVEP中心区损害重于周边区,波形异常程度与弱视程度无关。内斜性弱视波形异常程度大于外斜性弱视。     

Multifocal VEP in patients with optic nerve disease

AIM:To determine whether the multifocal visual evoked potential (mfVEP) can be used as a clinical method to assess the patients with optic nerve disease. METHODS:Fifteen patients with optic nerve disease were examined in this study. All patients underwent visual acuity examination, slit-lamp inspection, ophthalmoscopy, Goldmann perimeter, fundus fluorescein angiography, visual field and mfVEP. Although these patients with unilateral optic nerve damage,data from both eyes were included in the analysis. RESULTS:In all patients the visual fields defect was demonstrated on the mfVEPand showed good correspondence in location of the scotoma. However, we also found some slight difference between visual field and mfVEP. In some locations, when the local visual fields were normal, mfVEP showed that its amplitude reduced. In reverse, when the local mfVEPseemed normal, visual field showed abnormity. CONCLUSION:Multifocal visual evoked potential could be used as a clinical diagnosis option in patients with optic nerve disease. Local monocular damage to the optic nerve can be measured by an interocular comparison of the mfVEP     

多焦视觉诱发电位用于诊断视神经病变

目的:探讨多焦视觉诱发电位在视神经病变诊断中的应用价值.方法:对15例视神经病变患者行常规眼科视力、裂隙灯检查、眼底检查、Goldmann眼压测定、眼底荧光血管造影、视野和mfVEP检查.对受检者双眼mfVEP检查的波形结果进行相互比较,并与视野检查结果进行相互比较及对应一致性分析.结果:在所有视神经病变眼均检测到明显的mfVEP波形改变,其与视野的改变具有对应一致性.部分视神经病变眼局部mfVEP波形改变同视野改变略有差别.结论:mfVEP在视神经病变的诊断中具有独特的优势,有望成为一种视神经病变诊断的新方法.双眼间比较有助于发现单眼局部的视神经损害.     

弱视儿童多焦视觉诱发电位的分析

目的分析儿童多焦视觉诱发电位的变化,探讨弱视眼视野各部位视功能的损害。方法采用多焦视觉电生理仪检查54只弱视眼,并与48只正常眼结果比较。结果弱视眼mfVEP振幅密度的下降和潜伏期的延长在中央视野较显著,在周边部分无明显差异。弱视程度与振幅密度及潜伏期之间存在相关性。结论儿童弱视眼在视野中央部分视功能下降较显著。