Multifocal electroretinogram delays reveal local retinal dysfunction in early diabetic retinopathy.

PURPOSE: To identify local retinal abnormalities in diabetic patients with and without retinopathy, by using the multifocal electroretinogram (M-ERG). METHODS: Electroretinograms were recorded at 103 discrete retinal locations in each eye of eight persons with nonproliferative diabetic retinopathy (NPDR) and eight diabetic persons without retinopathy, using VERIS (EDI, San Mateo, CA). The amplitude and implicit time of each local (first-order) retinal response were derived and compared with normal values obtained from 16 age-matched, nondiabetic subjects. Maps of local response amplitude and implicit time were compared with fundus photographs taken at the time of testing. RESULTS: In eyes with NPDR, the implicit times of responses from retinal sites manifesting clinical pathologic fundus lesions (e.g., microaneurysms and focal edema), were markedly delayed (e.g., up to 7 msec from normal). Responses from adjacent retinal sites that were more normal in clinical appearance were also delayed, but to a lesser extent (e.g., 2-5 msec). Smaller, yet significant local response delays were also found in eyes without retinopathy. By contrast, local response amplitudes bore no consistent relationship to fundus abnormalities in eyes with retinopathy, and amplitudes were typically normal in eyes without retinopathy. CONCLUSIONS: The M-ERG reveals local retinal dysfunction in diabetic eyes even before retinopathy. The magnitude of delay of local ERG implicit time reflects the degree of local clinical abnormality in eyes with retinopathy. Local response delays found in some eyes without retinopathy suggest that the M-ERG detects subclinical local retinal dysfunction in diabetes. Analysis of M-ERG implicit time, independent of amplitude, improves the sensitivity of detection of local retinal dysfunction in diabetes.     

亚临床期糖尿病视网膜病变的多焦视网膜电流图

多焦视网膜电流图(multifocalelectroretinogram,mERG或mfERG)是一种新兴的眼科检查手段,通过使用特殊m-序列刺激手段短时间内提取局部ERG信号,客观、定量地反映视网膜功能。糖尿病引起的眼部并发症是糖尿病患者致盲的一个主要原因,能够在亚临床期早期诊断糖尿病视网膜疾病(diabeticretinopathy,DR),对于预防和治疗DR有着重要的意义。mERG能够客观地检测DR,应用于研究和临床,评估那些预防和治疗DR方法的效果。     

Multifocal electroretinogram responses in Nepalese diabetic patients without retinopathy

Purpose

To determine neuroretinal function with multifocal electroretinogram (mfERG) in diabetic subjects without retinopathy.

Methods

Multifocal electroretinogram (mfERG) was performed in 18 eyes of 18 diabetic subjects without retinopathy and 17 eyes of 17 age and gender-matched healthy control participants. Among 18 diabetic subjects, two had type 1 and 16 had type 2 diabetes. MfERG responses were averaged by the retinal areas of six concentric rings and four quadrants, and 103 retinal locations; N1–P1 amplitude and P1-implicit time were analysed.

Results

Average mfERG N1–P1 amplitude (in nv/deg²) of 103 retinal locations was 56.3 ± 17.2 (mean ± SD) in type 1 diabetic subjects, 47.2 ± 9.3 in type 2 diabetic subjects and 71.5 ± 12.7 in controls. Average P1-implicit time (in ms) was 43.0 ± 1.3 in type 1 diabetic subjects, 43.9 ± 2.3 in type 2 diabetic subjects and 41.9 ± 2.1 in controls. There was significant reduction in average N1–P1 amplitude and delay in P1-implicit time in type 2 diabetic subjects in comparison to controls. mfERG amplitude did not show any significant correlation with diabetes duration and blood sugar level. However, implicit time showed a positive correlation with diabetes duration in type 2 diabetic subjects with diabetes duration ≥5 years.

Conclusions

This is the first study in a Nepalese population with diabetes using multifocal electroretinography. We present novel findings that mfERG N1–P1 amplitude is markedly reduced along with delay in P1-implicit time in type 2 diabetic subjects without retinopathy. These findings indicate that there might be significant dysfunction of inner retina before the development of diabetic retinopathy in the study population, which have higher prevalence of diabetes than the global estimate and uncontrolled blood sugar level.     

多焦视网膜电图及彩色多普勒在糖尿病视网膜病变早期诊断中的应用比较

目的 比较多焦视网膜电图（mfERG）与彩色多普勒在糖尿病视网膜病变（DR）早期诊断中的应用.方法 采用横断面研究,运用mfERLG检测正常对照组22例（22眼）、糖尿病无DR组52例（52眼）及DR单纯期组32例（32眼）.在上述患者中运用彩色多普勒测量视网膜中央动脉（CRA）的血流.采用单因素方差分析方法以及S-N-K法进行统计学分析.结果 糖尿病患者中,无DR组mfERG环1至环3中P1波反应密度低于正常对照组（P＜0.05）;CRA的血流则无异常变化（P＞0.05）.在DR单纯期组,mfERG除上述指标异常以外,Pt波潜伏期也出现延长（P＜0.05）.CRA的流速比正常对照组及无DR组降低（P＜0.05）.结论 在DR的临床早期诊断中,mfERG比彩色多普勒检测CRA血流的方法更敏感.     

Multifocal electroretinogram in diabetic subjects

PurposeTo identify local retinal abnormalities and evaluate the nature and extent of retinal dysfunction in diabetics using full field electroretinogram (ERG) and multifocal ERG (MF-ERG) and to determine the correlation between features of optical coherence tomography (OCT) and MF-ERG.MethodsTwenty-eight normal subjects (Control Group; 56 eyes) and 37 patients (72 eyes) with diabetes mellitus (DM Group) were evaluated. In the DM Group, 17 eyes had no retinopathy (grade 1), 18 eyes had early non proliferative diabetic retinopathy (NPDR) (grade 3), 16 eyes had late NPDR (grade 4), 21 eyes had proliferative diabetic retinopathy (PDR) (grade 5). Full field ERG and MF-ERG, were used to assess the effects of diabetic retinopathy on retinal function. OCT and fluorescein angiography were used to assess and compare morphological changes with functional changes in diabetes mellitus.ResultsIn diabetic patients without retinopathy (17 eyes), the amplitudes of the second order component of MF-ERG were reduced and implicit times were delayed, while only implicit times of first order component of MF-ERG were delayed but the amplitudes of first order component were normal. In diabetic patients with retinopathy (55 eyes), the overall amplitudes were reduced and peak implicit time increased in the first order component and second order component.OCT of the DM Group showed the fovea of eyes with edema were thicker than the Normal Group. The fovea of eyes with cystoid macular edema (CME) were significantly thicker than the fovea of eyes with diffuse swelling. The implicit times of MF-ERG were directly correlated with foveal thickness.ConclusionMF-ERG reveals local retinal dysfunction in diabetic patients. MF-ERG offers the advantage of topographic mapping of retinal dysfunction. The magnitude of delay of MF-ERG implicit time reflects the degree of local clinical abnormalities in eyes with retinopathy. Local response delays found in eyes without retinopathy detects subclinical local retinal dysfunction in diabetics. The combination of OCT and MF-ERG may provide objective criteria for evaluation and assessment of diabetic retinopathy.     

The electroretinogram in diabetic retinopathy.

Electroretinography (ERG) is an objective method of evaluating retinal function. Since its introduction to clinical practice in the 1940s, it has become a useful and routine diagnostic clinical tool in ophthalmology. This review summarizes the role of ERG as a clinical technique for evaluating the progression of diabetic retinopathy and as a research tool for increasing our understanding of the pathophysiology of diabetic retinopathy. Most studies show unequivocally that the different types of ERG tests detect local abnormalities or widespread pathology, even in very early stages of the disease. It seems plausible that measurements from ERG recordings, particularly the oscillatory potentials, may be useful for predicting progression from nonproliferative to the more sight-threatening stages--preproliferative or proliferative--of diabetic retinopathy. Some recent work implies that the ERG can also be a useful diagnostic method for discriminating between eyes with diabetic retinopathy and those without the condition.     

Multifocal electroretinogram

The paper presents current state of knowledge regarding multifocal electroretinography (mfERG). The theoretical basis of this technique, procedure, methods and examples of use in clinical diagnostics are presented.     

早期糖尿病视网膜病变的视网膜电图分析

目的 分析早期糖尿病视网膜病变(DR)的闪光视网膜电图(F—ERG)和视网膜电图震荡电位(OPs)各参数的变化特点，寻找反映早期DR的敏感指标。方法 对16例(32只眼)正常人进行OPs和F-ERG检测。对27例(53只眼)糖尿病病人进行眼底荧光血管造影(FFA)、OPs和F—ERG检测。结果 OPs中Os波幅、O4波幅、OPs总波幅及F-ERG中b波峰潜时较其他指标敏感，其中O4波幅和b波峰潜时为最敏感指标，但均不能反映早期DR的严重程度。结论 OPs的O4波幅和F—ERG的b波峰潜时可作为早期糖尿病视网膜病变诊断的敏感指标。     

The electroretinogram in minimal diabetic retinopathy.

The pattern and diffuse flash electroretinograms were measured in 20 normal subjects and 40 diabetic patients who had either normal fundi or microaneurysms only. The amplitudes of the pattern electroretinogram were found to be similar in both normals and diabetics. In the case of the flash electroretinogram the diabetic patients showed a division into two main groups. One group was not dissimilar to the group of normal subjects, while the second group showed hypernormal amplitudes. No explanation could be given, from the data collected, for this subdivision, though it is suggested it might reflect the degree of metabolic disturbance.     

不同类型糖尿病性黄斑水肿的多焦视网膜电图分析

背景了解糖尿病患者的视网膜功能变化对于指导临床治疗非常重要。目前对糖尿病性黄斑水肿（DME）患者的研究包括荧光素眼底血管造影（FFA）、多焦视网膜电图（mfERG）等,但对不同类型DME患者mfERG特征的研究较少。目的探讨不同类型DME患者的mfERG改变。方法病例对照研究。对确诊糖尿病视网膜病变（DR）合并临床显著黄斑水肿的40例57眼进行mfERG和FFA检查,同时对年龄和性别相匹配的正常对照组35例35眼行mfERG检查,并进行比较。依照FFA表现将DME分为局限型DME13例16眼、弥漫型DME17例22眼和囊样型DME12例17眼,分析各类型DME患者mfERG的特征。结果与正常对照组比较,局限型DME组患者mfERG1环的P．波反应密度显著下降,P。波4环、5环隐含时明显延迟,差异均有统计学意义（t=2．170,P=0．038;t=2．519,P=0．017;t=2．451,P=0．020）;4环N1波隐含时明显延迟,差异有统计学意义（t=2．858,P=0．008）。弥漫型DME组患者1、3、5环P。波反应密度显著下降,1、3、4、5环N1波反应密度显著下降,差异均有统计学意义（P〈0．05）;3环、4环P,波隐含时明显延迟,差异均有统计学意义（t=2．446,P=0．019;t=2．759,P=0．009）。与正常对照组比较,囊样型DME组患者1～5环P,波反应密度显著下降,1、3、4、5环N．波反应密度显著下降,差异均有统计学意义（P〈0．05）;3、4、5环P。波隐含时明显延迟,4环N,波隐含时明显延迟,差异均有统计学意义（P〈0．05）。黄斑区功能在中心凹处严重受损,外环功能虽有不同程度下降,但均较中心凹功能下降程度轻。结论不同类型DME的局部视网膜功能改变程度与FFA的形态学表现结果一致,各型DME患者中黄斑中心凹功能受累程度由重至轻依次为囊样型DME、弥漫型DME及局限型DME。FFA与mfERG联合诊断可以全面、多角度地反映糖尿病患者黄斑区功能的变化情况。     

增生型糖尿病视网膜病变多焦视网膜电图的观察分析

目的:观察增生型糖尿病视网膜病变(proliferative diabetic retinopathy,PDR)的多焦视网膜电图(multifocal electroretinogram,mf-ERG)的图像特征及临床意义.方法:对临床确诊的PDR患者40例44眼(PDR组)和正常对照组40例40眼进行mf-ERG检查,并对所得数据进行统计分析.结果:PDR患者组mf-ERG 1~5环的反应密度均低于正常对照组,且有显著性差异,N1波潜伏期在4环、P1波潜伏期在2~5环与正常对照组相比显著延长.结论:Mf-ERG可有效地评价PDR患者视网膜的功能.     

多焦视网膜电图在亚临床期糖尿病视网膜病变中的变化

目的:探讨多焦视网膜电图(multifocal electroretinogram,mf-ERG)的一阶(first order kernel,FOK)和二阶(second order kernel,SOK)反应在亚临床期糖尿病视网膜病变的变化.方法:回顾性分析,选取2014-06/2015-05确诊为2型糖尿病,但眼底无糖尿病视网膜病变患者32例58眼作为糖尿病组,进行多焦视网膜电图一阶反应、二阶反应检查,并与同期门诊检查的正常组对照.结果:与正常对照组相比,糖尿病组FOK总和反应b波潜伏期无明显延迟,而b波的振幅降低,差异有统计学意义(t=3.099,P=0.012).糖尿病组SOK总和反应b波的峰时延迟,差异有统计学意义(t=2.643,P=0.025),且b波的振幅降低,差异有统计学意义(t=4.833,P<0.01).糖尿病组a波在FOK和SOK中的振幅和潜伏期变化差异均无统计学意义.将b波振幅、潜伏期分别与糖尿病病程行相关性分析,结果显示b波振幅与病程呈负相关,而b波潜伏期与病程无相关性.结论:在亚临床期糖尿病视网膜病变中FOK、SOK均有变化,主要反映在b波的振幅变化.     

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.     

糖尿病视网膜病变黄斑区视网膜厚度与mERG的观察研究

目的探讨糖尿病视网膜病变(DR)黄斑区视网膜厚度与多焦视网膜电图(mERG)的变化及相互关系。方法采用视网膜厚度分析仪(RTA)对34例(68眼)糖尿病患者及mERG对23例(45眼)糖尿病患者进行检测。结果从无视网膜病变的糖尿病(NDR)患者到Ⅰ期、Ⅲ期DR患者的黄斑区视网膜厚度呈增加趋势,Ⅲ期DR患者的黄斑区各部位视网膜厚度均较正常对照组增加,经统计学分析差异有显著性意义(P<0.01或0.05);且与视力呈显著负相关(P<0.05)。Ⅰ期DR患者的P1波及N2波反应密度较NDR患者减少(P<0.01或0.05),Ⅲ期DR患者的N1波、P1波、N2波潜伏期分别较NDR患者或Ⅰ期DR患者延长,各波反应密度分别较NDR或Ⅰ期DR患者减少(P<0.01或0.05)。中心凹区视网膜平均厚度与P1波潜伏期及反应密度呈显著相关(P<0.05);黄斑区及旁中心凹区的视网膜平均厚度与N2波反应密度及潜伏期呈显著相关(P<0.01或0.05)。结论当黄斑区视网膜厚度增加时,相应的视网膜功能出现损害,RTA结合mERG的检查,可更加全面地反映DR患者黄斑区视网膜的变化。     

视网膜电图诊断早期糖尿病视网膜病变

视网膜电图是一项评价视网膜功能的客观检查,适用于评价多种眼科疾病的视网膜功能情况。近年研究发现,在早期糖尿病患者中,视网膜电图能够发现先于眼底视网膜形态学改变的功能变化,这一点为糖尿病视网膜病变的病理机制研究、早期诊断、以及预后评估提供了新思路,进而可能为治疗糖尿病视网膜病变提供新途径。我们就运用视网膜电图诊断早期糖尿病视网膜病变进行综述。