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。     

多焦视网膜电图及其在青光眼早期诊断中应用

多焦视网膜电图(multifoca elelectroretinogram,mfERG)在眼科领域的应用是视觉电生理的一项重要新进展.用它评价视网膜外层和中层功能障碍(如视网膜营养不良)的价值已得到肯定.但用多焦视网膜电图检测主要以内层视网膜损害为主的青光眼,尤其是用于早期诊断,仍存在许多问题有待解决.此文介绍了多焦视网膜电图的基本原理、正常人多焦视网膜电图特征、青光眼及高眼压症多焦视网膜电图的改变以及多焦视网膜电图与青光眼视野缺损的关系.     

多焦视网膜电图在青光眼早期诊断中的应用

多焦视网膜电图（multifocalelectroretinogram，mfERG）在眼科领域的应用是视觉电生理学的一项重要新进展，用它评价视网膜外层和中层功能障碍（如视网膜营养不良）的价值已得到肯定。但用多焦视网膜电图检测主要以内层视网膜损害为主的青光眼，尤其是用于早期诊断，仍存在许多问题有待解决。本文介绍了多焦视网膜电图的基本原理、正常人多焦视网膜电图特征、青光眼及高眼压症多焦视网膜电图的改变以及多焦视网膜电图与青光眼视野缺损的关系。     

视网膜色素变性患者的多焦视网膜电图与视网膜光学相干断层扫描的观察分析

目的研究视网膜色素变性(RP)患者的多焦视网膜电图(mERG)与视网膜光学相干断层扫描(OCT)的特性及图像特征。方法对已确诊的6例(12只眼)原发性视网膜色素变性患者和10例(20只眼)正常人的视网膜进行多焦视网膜电图与视网膜光学相干断层扫描检查,并对所得数据进行统计分析。结果RP患者视网膜黄斑中心凹厚度平均值低于正常人,但两者之间无显著差异性,RP患者OCT的视网膜断层反射像与正常反射像相比有较明显的改变;RP患者的多焦视网膜电图各环的反应密度均低于正常人,且有显著性差异,4~6环的潜伏期与正常人相比显著延长。结论多焦视网膜电图可有效地评价RP患者黄斑区及周边视网膜的功能,RP患者OCT的断层扫描像与其已知的视网膜病变特点相一致。     

糖尿病视网膜病变的多焦视网膜电图的研究进展

糖尿病视网膜病变(DR)是糖尿病并发的一种严重的致盲性眼病,其复杂的病理变化破坏了视网膜的正常功能.多焦视网膜电图(mERG)作为一项新的视觉电生理检查技术,能在相对较短的时间内测量整个测视野中许多细小部位的ERG,其一阶反应可反映局部视网膜内层和外层的功能,目前这项技术在糖尿病视网膜病变的研究中得到了广泛的应用.本文就近年来糖尿病视网膜病变的多焦视网膜电图的研究进展做一综述.     

多焦视网膜电图在视网膜疾病中的应用

多焦视网膜电图通过互相关技术可以同时记录视网膜不同局域的视网膜电反应信号,继而可以显现视网膜中央40°～50°的功能地形图,其优势在于:能够在较短的时间内提供客观的中心视网膜功能评估地形图.为此,本文基于当前的文献报道,对多焦视网膜电图在常见的后天获得性视网膜疾病中的临床应用进行综述.     

多焦视网膜电图的原理及应用

多焦视网膜电图是国际上近十年逐渐发展起来的一种优于全视野和局部视网膜电图的新颖电生理记录技术,它将kemel分析法和电子计算机技术引入电生理信号记录中,较传统视网膜电图更为精细,分辨率更高.本文就多焦视网膜电图起源、记录原理和方法、波形特征、影响因素及其临床应用等作一综述,并提出了多焦视网膜电图尚需解决的问题.     

三个时期糖尿病视网膜病变多焦视网膜电图的差异

目的研究三个时期糖尿病视网膜病变的多焦视网膜电图特征及其临床意义。方法采用VERISⅣ视觉诱发反应图像系统测量和分析了34例非增殖期、15例增殖前期和15例增殖期糖尿病视网膜病变的多焦视网膜电图的差异。结果与正常对照眼比较,增殖期糖尿病视网膜病变,多焦视网膜电图的N     

多焦视网膜电图一级反应的测量和分析

目的　对多焦视网膜电图一级反应进行测量并对各种变异进行分析。方法　应用 VERIS 4 .0视觉诱发反应图像系统对三组不同年龄组的正常人 (共 4 4例 5 0只眼 )及各种眼病病人 (共 12 5例 15 0只眼 )进行检查。结果　正常人多焦视网膜电图振幅在第一环处反应密度最高 ,随着离心度增加 ,反应密度值逐渐降低 ;潜伏期在第 3环处最短 ,向 1环处和 6环处渐增加 ;随年龄增加 ,各环各波振幅有所降低而潜伏期有所延长。不同类型视网膜病变的多焦视网膜电图改变模式不同。结论　多焦视网膜电图在正常人存在年龄性影响 ,在患者存在病变部位和程度的影响     

多焦视网膜电图测定的影响因素

目的：探讨多焦视网膜电图（multifocal electroretinography,MERG)测定过程的步骤及注意事项。方法：对131例受试者进行多焦视网膜电图测定过程中注意事项的回顾性研究。结果：发现多焦视网膜电图测定过程中存在许多变异因素,如受试者的配合,电极的安装,眼的固视与屈光聚焦旋钮的调整等。良好的MERG记录与检查者的技术有密切关系。结论：多焦视网膜电图的测定过程必须步骤进行,以确保结果的可靠性和可重复性。     

多焦视网膜电图在视网膜疾病中的应用进展

多焦视网膜电图(mfERG)是视网膜电图(ERG)中的一种常见类型,它能够客观、准确、定量地检测视网膜各个细小部位的功能,在临床上被广泛应用,尤其是在视网膜疾病中,它不仅在视网膜疾病的诊断与疗效评价中有着重要作用,而且最近的研究发现它在疾病的随访和预后评估中也具有重要价值,甚至其应用范围可向基础研究推广。因此本文对mfERG在视网膜疾病中的应用进展作一综述。     

Pattern-reversal electroretinograms for the diagnosis and management of disorders of the anterior visual pathway

The pattern electroretinogram is an electrophysiological test that assesses the function of inner retinal layers, particularly the ganglion cells layer of retina, using a reversing checkerboard or grating pattern that produces no change in average luminance over time. The normal pattern electroretinogram is composed of a proeminent positive component (P50) and a large later negative component (N95). Since structural damage that compromises the retinal ganglion cell layer can lead to pattern electroretinogram changes, particularly in the N95 amplitude, the test can be useful in the treatment of a number of anterior visual pathway diseases. In this article, we review the methods for recording pattern electroretinogram and its usefulness in the diagnosis and management of diseases including inflammatory, hereditary, ischemic and compressive lesions of the anterior visual pathway.     

Simplified electroretinography protocol and diagnosis of retinal dystrophies in children]

PURPOSE: To report results of a simplified electroretinogram in children. PATIENTS: 124 children under 6 years of age with nystagmus, blindness, neurological disease, cone rod dystrophy in the family, or abnormal fundus appearance were examined. METHOD: The electroretinogram was recorded by corneal electrodes in an awake state without sedation. A light-emitting orange diode stimulator was used. Stimulation was performed subsequently after 3 minutes of light adaptation and after 8 minutes of darkness. If the electroretinogram was abnormal, a second recording was done a few weeks later using the same method. In some cases, the children were re-examined, and a ganzfeld stimulation ERG was recorded. RESULTS AND DISCUSSION: This method allowed a reliable diagnosis of photoreceptor dystrophy: Leber's congenital amaurosis with or without rare metabolic diseases, X link pigmentary retinopathy or retinal dystrophy with general disease in children. It helped to differentiate isolated retinal pigment changes with normal electroretinogram from functional retinal impairment and rod-cone dystrophy from other retinal dystrophies.     

Pattern electroretinogram peak times as a clinical means of discriminating retinal from optic nerve disease

Fifty-two patients with unilateral or bilateral retinal or optic nerve disease exhibited abnormal peak times and/or amplitudes in the pattern electroretinogram. While this abnormality in patients with optic nerve diseases was confined to an amplitude reduction, 40% of the eyes with retinal diseases exhibited additionally a peak time delay of the p and/or q component. We conclude that recording of pattern electroretinogram peak times provides an additional means to distinguish retinal from optic nerve diseases.     

Screening for mouse retinal degenerations

Mice with hereditary retinal degeneration have provided excellent models for human disease of the biochemical and physiological events occuring in retinal degeneration. Since a number of mouse models are available for other human conditions, more mouse retinal degenerations would be expected to be known; however, finding new models has proved difficult since the search has usually involved laborious histologic screening.We applied the clinical technique of indirect ophthalmoscopy to screen mice for retinal degeneration and then used electroretinography and histology to determine whether true retinal degeneration was present.A Dawson-Trick-Litzkow microfiber corneal electrode was used to record the electroretinogram since the fiber does not occlude the pupil in these small eyes. Normal control values were developed. As an example of the success of the technique, one strain, lethal spot (ls) on indirect ophthalmoscopy appeared to have a retinal degeneration, but these mice had a normal electroretinogram indicating a primary optic atrophy. Likewise, one ls heterozygote that was tested as a control animal and was not suspected of having a retinal degeneration had an abnormal electroretinogram and peripheral retinal degeneration.     

The multifocal electroretinogram in age-related maculopathies

To measure and compare the multifocal electroretinogram in control group and patients with age-related maculopathies, 17 eyes of control subjects, 9 eyes of wet-form ARMD, 8 eyes of dry-form ARMD and 14 eyes of idiopathic macular hole were tested with VERIS Sciences^TM 4.0. The latencies and average response densities of 6 ring retinal regions in control eyes were compared with those in ARMD and macular hole. The amplitude depression and latency prolongation were found in age-related maculopathies. The changes of multifocal ERG were dramatic in wet-form ARMD and moderate in dry-form ARMD and IMH, which were correspondent with the pathological changes of the diseases. Our results suggest that the multifocal electroretinogram can be used to quantity the visual function in age-related maculopathies.     

Late onset cone dystrophy

Cone dystrophies are a hereditary, progressive and heterogeneous group of retinal diseases with cone system degeneration. They lead to reduced visual acuity, colour vision impairment and photophobia. Full-field electroretinogram (ERG) reveals severe cone function impairment, with normal rod responses or slightly depressed in advanced stages in some cases. The purpose of the study was to present a case of late onset cone dystrophy in 47-year-old male and the proper diagnostic procedure. A 47-year-old patient presented with progressive visual loss for several years and mild photophobia, which he observed recently. The patient underwent fundus photography, fluorescein angiography, colour vision testing, Goldmann visual field testing, full-field electroretinogram (ERG) and multifocal electroretinogram (mfERG). Symptoms and signs of late onset cone dystrophy may be unclear and establishing the proper diagnosis may be difficult in these cases. Patients may be misdiagnosed as having other diseases, especially in case of absence or subtle changes in the macula. The electrophysiological testing is essential in these cases, and ERG is the most useful clinical test in early and differential diagnosis of retinal dystrophies.     

Guidelines for clinical electroretinography in the dog: 2012 update

The full-field, flash electroretinogram (ERG) is now a widely used test of canine retinal function for the clinical diagnosis of hereditary retinal dystrophies and other causes of retinal degeneration, assessment of retinal function in patients with opaque media, ruling out of generalized retinal diseases in patients with sudden loss of vision and in ophthalmological research, as well as in pharmaceutical and toxicological screening for deleterious side effects of drugs and other chemical compounds. In 2002, the first guidelines for clinical ERGs in this species adopted by the European College of Veterinary Ophthalmologists were published. This work provides an update of these guidelines.     

Pattern electroretinogram in glaucoma

PURPOSE OF REVIEW: Several studies have shown that the pattern electroretinogram, a direct, objective method of measuring retinal ganglion cell function, is altered early in ocular hypertension and glaucoma. Renewed interest in the pattern electroretinogram for early detection of pre-perimetric glaucoma has been sparked by noninvasive and reproducible methods of recording using skin electrodes. RECENT FINDINGS: With the noninvasive pattern electroretinogram, response abnormalities have been detected in up to 50% of glaucoma suspects with normal standard perimetry. In early glaucoma (with either normal or high intraocular pressure), a reduction of intraocular pressure has sometimes yielded improvement in pattern electroretinogram amplitude. A prolonged steady-state stimulus presentation reduces the pattern electroretinogram amplitude and increases optic nerve blood flow in normal subjects, suggesting that sustained activity of retinal ganglion cells is physiologically associated with autoregulatory changes of the neural-vascular system. It is unknown whether this autoregulation is altered in glaucoma. The multifocal pattern electroretinogram does not seem to have an advantage over the pattern electroretinogram in the early detection of glaucoma. The photopic negative response of the diffuse flash electroretinogram has shown changes in glaucoma, but may not be able to detect retinal dysfunction in normal tension glaucoma. SUMMARY: The pattern electroretinogram is a noninvasive, direct, objective method that may be useful to clinicians in detecting early retinal ganglion cell dysfunction in glaucoma suspects. The pattern electroretinogram may also optimize treatment strategies based on improvement of retinal ganglion cell function.