实验性眼冲击伤视网膜电图的改变

实验性兔眼冲击伤后，视网膜电图（ERG）a、b波振幅明显降低，分别约为伤前35%及54%，并于伤后14d，21d才恢复至伤前水平。地塞米松合并蝮蛇抗栓酶治疗组ERG a、b波振幅恢复早于对照组及地塞米松合并妥拉苏林或单纯用地塞米松的两个治疗组。表现一定能量的冲击波可造成明显的视网膜功能损害，ERG可作为检测损伤程度，客观评价疗效的重要指标。 （中华眼底病杂志，1995，11：169-171）     

眼铁锈沉着症的闪光视网膜电图变化

眼球穿孔伤常合并眼球内异物,较小异物常不能及时明确诊断。在眼内异物中铁最常见,铁在眼内可引起铁锈沉着症而损害视功能。为了探讨其对视网膜功能的影响,我们对29例29眼铁锈沉着症患者行闪光视网膜电图(F—ERC)测定。现将其结果分析如下。一、对象与方法 1、对象:确诊眼内铁异物29人,男15人,女14人,年龄20～69岁,平均年龄39.3岁,病程1个月到3年不等。术前X线检查阳性22人,阴性7人。手术22例取出磁性异物,7例取不出异物,其中6人X线阴性,但晶体有较明显铁锈沉着。21例同时行内障手术,术前或术后发现有明显玻璃体积血者除外,外伤前视力差者除外。以对     

大剂量地塞米松治疗兔视网膜冲击伤

目的 评价大剂量地塞米松对兔视网膜冲击伤的疗效。方法 采用ＢＳＴ－３型生物激波管建立视网膜冲击伤兔模型,将２４只兔随机分为大剂量地塞米松（６ｍｇ．ｋｇ＾－１）组治疗组和生理盐水对照组。结果 大剂量地塞米松治疗组眼底病变较对照组吸收快,病理变化减轻,视网膜电图ｂ波波幅的恢复时间缩短。结论 大剂量地塞米松的治疗可减轻视网膜冲击伤后组织的损伤,缩短病程,改善功能,具有较好的治疗效果。     

视网膜静脉阻塞的视觉眼电图改变

本实验分别记录了正常眼组及视网膜静脉阻塞组的视觉眼电图，结果表明，虽然视网膜静脉阻塞时睫状血管系统不受影响，但是其ＥＯＧ与正常眼组比较，十项诊断指标中八项指标的差异具有高度显著性。同时，ＢＲＶＯ组与ＣＲＶＯ组比较时，八项诊断指标具有显著性差异。ＢＲＶＯ组与正常眼组进行检验时，五项诊断指标的差别具有显著性。当视网膜静脉阻塞后期组与正常眼组相比时，十项诊断指标的差别均无显著性意义，可以认为，ＥＯＧ在判断视网膜缺血程度上具有一定价值，同时，本文对视网膜静脉阻塞影响ＥＯＧ的机制进行了初步的探讨。     

正常眼多焦视网膜电图分析

确定多焦视网膜电图的正常值和分析不同部位视网膜刺激反应密度的差异,为客观评价后极部视网膜病变的功能提供参考依据。方法Ｖｅｒｉｓ视网膜功能分析列扩瞳正常眼,对后极部视网膜局部反应振幅和潜伏期进行分析。结论正常眼视网膜后极部由于感光细胞剖解分布的不同,多焦视网膜电图局部反应密度振幅有一定差异。     

室内爆炸犬眼冲击伤后早期眼组织病理结构改变

目的:观察犬眼室内爆炸冲击波损伤后早期眼组织结构的病理学改变。方法:爆轰塔内B炸药爆炸致眼冲击伤,根据对眼球的不同爆炸强度随机分组:A组549mmHg;B组1089mmHg;C组2128mmHg;D组无致伤对照组。均分别于伤后0.5h和6h处死动物,取眼组织标本于40g/L中性甲醛溶液固定,行常规石蜡包埋,切片,HE染色,光镜观察,拍照。结果:眼部冲击伤后即刻出现球结膜充血、水肿,脉络膜出血,有明显的视网膜血管改变,组织水肿、渗出、出血等改变。结论:爆轰塔内B炸药爆炸致眼冲击波可造成视网膜、脉络膜、视神经的直接损伤。     

正常眼多焦视网膜电图特征的初步探讨

目的 :初步分析正常人眼多焦视网膜电图 (m ERG)测量值 ,并探讨正常眼视网膜后极部不同部位的电生理功能。方法 :对 19例 (2 5眼 )散瞳正常眼作多焦视网膜电图检查 ,记录 6 1个部位反应波形图 ,分析视网膜后极部不同区域的a波 (第 1个负波 )和b波 (第 1个正波 )的潜伏期、振幅值及振幅密度。结果 :视网膜后极部中心环 (第 1环 )振幅密度为最高 ,a波为 (33.92± 18.95 )nV/deg2 ,b波为 (6 8.78±19.84 )nV/deg2 ,随着离心度的增加 ,各振幅密度逐渐下降 ,差异有显著性 (P <0 .0 1)。a波及b波潜伏期、振幅及振幅密度在四个象限的差异均无显著性 (P >0 .0 5 )。结论 :多焦视网膜电图能客观、定位、定量地测定视网膜后极部不同部位的视功能 ,其测定的正常值为临床研究提供了参考数值     

早期糖尿病视网膜病变的视网膜电图研究

目的：研究早期糖尿病视网膜病变（diabeticretinopathy,DR) 的视网膜电图震荡电位（Oscillatory potentials,OPs)和图形视网膜电图（Pettern electroretinogram,P-ERG)的变化特点,借以早期诊断DR。方法：对20例（40眼）正常和50例（113眼）糖尿病病人进行OPs和P－ERG检测。结果：当糖尿病病人眼底尚未出现改变时,P－ERG的b波波幅和OPs各子波波幅及总波幅已降低。随着DR的发展,各参数的异常率逐渐上升,各波波幅也随之下降,潜伏期延长。OPs的O3波波幅和总波幅以及P－ERG的b波波幅较其它指标具有较高的敏感性,其中O3波波幅为最敏感的指标。结论：OPs的O3波波幅和总波幅等参数能够作为视觉电生理的功能性指标预测DR的发生,在DR的早期诊断和评价DM的疗效方面有临床应用价值。     

视网膜脱离手术复位后ERG的恢复

为探讨视网膜脱离手术复位后ERG的改变，对35例（35眼）患者进行手术前后ERG检测，结果表明；（1）视网膜脱离术前ERGa、b波幅明显低于有视网膜格子样变性而无脱离者。（2）手术复位后ERGa、b波幅随时间延长逐渐回升。（3）视网膜脱离范围二个象限以内者ERGa、b波幅回升高于二象限以上者。（4）手术范围一个象限以内者与超过一个象限者相比前者ERG恢复优于后者。（5）视网膜脱离时间2月以内与超过2月相比，ERG恢复前者明显优于后者。结果证实视网膜脱离术后ERG恢复与手术后时间、脱离范围、病程及手术范围密切相关。     

兔视网膜不同缺血时间再灌注后ERG的变化

目的：观察兔眼视网膜不同缺血时间再灌注后ERG的变化。方法：20只大白兔,双眼均行ERG测定后随机分成A组10只,均左眼视神经结扎30min,右眼暴露视神经后不结扎。B组10只,均左眼视神经结扎60min,右眼视神经结扎90min。分别测定再灌注0,3,24,48,168h ERGa、b波振幅（aA、hA）值。结果：未结扎组视网膜缺血-再灌注0,3,24,48,168h ERGaA、bA值未见显著性差异。结扎后兔ERGaA、bA值均明显下降,结扎30min与90min组ERGaA、bA值随着再灌注时间的延长逐渐上升,再灌注168h,结扎30min组的ERGaA、bA值恢复正常。结扎60min组,ERGaA、bA值在再灌注24h进一步下降,后又逐渐上升。结论：缺血60min,再灌注24h时视网膜功能受到进一步损伤,缺血30min和90min,再灌注期间未观察到视网膜功能进一步损伤的现象。     

家兔视网膜缺血-再灌注损伤后形态学的动态变化

目的　观察家兔视网膜缺血 -再灌注后视网膜结构的动态变化。方法　通过前房灌注加压至 16 .7k Pa,维持 1h,建立缺血模型 ,观察再灌注 2～ 14d内其结构变化及内层视网膜平均厚度的变化。结果　家兔视网膜在缺血 -再灌注后 2～ 14d内表现为神经细胞持续丢失 ,视网膜层次逐渐不清 ,萎缩、变薄。其中神经节细胞、神经纤维及视锥、视杆对缺血最敏感 ,外颗粒层次之 ,内颗粒层最能耐受缺血 -再灌注后的损伤。结论　视网膜缺血 -再灌注损伤是个持续性、进行性的损伤过程 ,与功能变化相一致     

球内铅异物伤时ERG与视网膜形态变化

研究了兔眼球内铅异物伤后的视网膜电图(ERG)和视网膜形态学变化。伤后2个月,ERG a 波降低75%,b 波降低66%;伤后3个月,视网膜各层细胞广泛出现肿胀、变性、甚至坏死。并对实验结果进行了分析和讨论。提出球内铅异物伤后,应在4周内手术取出异物。     

笃斯越橘对兔眼光损伤前后视网膜电流图及组织结构的影响

目的 探讨笃斯越橘对兔眼光损伤前后视网膜电流图(ERG)及组织结构的影响.方法 对照实验研究.采用随机数字表法将35只青紫蓝兔分为5组,每组7只兔.各组自由进食、摄水,对A、D组兔加用笃斯越橘匀浆.4周后,在光镜下观察D、E组兔视网膜组织学结构变化并测量光感受器细胞外核层(ONL)厚度及凋亡指数(AI);按照国际临床视觉电生理学会标准化方案确立的最大混合反应ERG及振荡电位(Ops)对A、B、C组兔视网膜进行检测.随后进行光损伤照射.照射后A组停用笃斯越橘,C组加用笃斯越橘,B组保持不变.在光照后1 d、1和2周进行ERG检测.检测完毕,取A、B、C组兔视网膜进行组织学分析.对各组兔视网膜ERG潜伏期、振幅、ONL厚度及AI值比较采用双因素及单因素的方差分析,进一步两两比较采用LSD检验法.结果 (1)最大混合反应ERG检测结果:A组饲养4周后,潜伏期:a波(14.079±0.841)ms,b波(35.629±6.865)ms;振幅:a波(83.936±10.807)μV,b波(280.931±27.807)μV.A组光照2周后,潜伏期:a波(15.571±1.087)ms,b波(38.915±7.683)ms;振幅:a波(66.478±9.709)μV,b波(245.887±11.797)μV.B组饲养4周后,潜伏期:a波(15.635±1.661)ms,b波(42.985±3.164)ms;振幅:a波(69.331±12.355)μV,b波(197.331±16.157)μV.B组光照2周后,潜伏期:a波(18.783±1.966)ms,b波(52.322±4.784)ms;振幅:a波(57.562±8.217)μV,b波(159.569±17.859)μV.C组饲养4周后,潜伏期:a波(15.115±0.940)ms,b波(43.242±4.662)ms;振幅:a波(72.812±4.403)μV,b波(207.815±14.373)μV.C组光照2周后,潜伏期:a波(15.957±2.154)ms,b波(44.081±9.506)ms;振幅:a波(66.804±8.755)μV,b波(186.271±29.349)μV.A、B、C组间最大混合反应ERG在饲养4周后及光照2周后差异有统计学意义(潜伏期a波:饲养4周后F=6.057,P＜0.05;光照2周后F=13.296,P＜0.05.潜伏期b波:饲养4周后F=9.949,P＜0.05;光照2周后F=11.145,P＜0.05.振幅a波:饲养4周后F=8.468,P＜0.05;光照2周后F=4.844,P＜0.05.振幅b波:饲养4周后F=70.194,P＜0.05;光照2周后F=62.161,P＜0.05);3组间ΣOPs值振幅差异有统计学意义(饲养4周后F=17.482,P＜0.05;光照2周后F=11.748,P＜0.05).进一步两两比较,显示光照前最大混合反应ERG振幅B组的a、b波及C组的a、b波均低于笃斯越橘饲养4周后的A组(B组的a波、b波振幅与A组比较:P=0.003,0.000;C组的a波、b波振幅与A组比较:P=0.001,0.000);光照1 d、1和2周后,A组的振幅b波较同期B组均明显升高(均P=0.000);光照后随用药时间延长,C组ERG检测值逐渐改善;光照2周后,C组较B组的b波潜伏期缩短,振幅提高(潜伏期P=0.008,振幅P=0.007).(2)视网膜组织学观察结果:光照前在光镜下观察兔视网膜组织,D、E组兔视网膜结构形态正常,光感受器细胞内外节排列整齐规则.B组视网膜结构排列紊乱,有光感受器细胞外节碎解.A、C组视网膜结构改变介于D、E和B组之间.各组间ONL厚度差异有统计学意义(F=330.506,P＜0.05).(3)各组间AI值差异有统计学意义(F=230.126,P＜0.05);B组AI值为(10.960±1.534)%,较各组明显增高(均P=0.000);D组AI值为(1.817±0.203)%,小于E组(P=0.000).结论 笃斯越橘对于暴露于正常昼夜日光交替下的兔视网膜有减少细胞凋亡、减轻光化学损伤的作用;预防性地使用笃斯越橘能明显降低光损伤的程度;光损伤后应用笃斯越橘有助于视网膜组织的修复.     

ERG changes in albino and pigmented mice after optic nerve transection

Optic nerve transection (ONT) triggers retinal ganglion cell (RGC) death. By using this paradigm, we have analyzed for the first time in adult albino and pigmented mice, the effects of ONT in the scotopic threshold response (STR) components (negative and positive) of the full-field electroretinogram. Two weeks after ONT, when in pigmented mice approximately 18% of the RGC population survive, the STR-implicit time decreased and the p and nSTR waves diminished approximately to 40% or 55%, in albino or pigmented, respectively, with respect to the values recorded from the non-operated contralateral eyes. These changes were maintained up to 12 weeks post-ONT, demonstrating that the ERG-STR is a useful parameter to monitor RGC functionality in adult mice.     

Pigment epithelial changes in a strain of pigmented rabbits with low ERG b-wave amplitudes

Retinas from a strain of rabbits with low dark-adapted electroretinographic (ERG) b-wave amplitudes, and declining ERG responses with time, were examined by light and electron microscopy. Seven rabbits from the affected strain (13 months to 5 years old) and six control animals (6-26 months old) were included in the study. Small inclusions with an electron dense border, about 0.2-1.5 microm in diameter, were significantly (p<0.01) more numerous within the retinal pigment epithelial (RPE) cells in the affected rabbits than in the control animals. No morphological evidence of retinal degeneration was found. Further studies are needed to establish the functional defect in this strain of rabbits.     

Dose-related changes in retinal function and PKC-alpha expression in rabbits on vigabatrin medication

Background  To investigate, in a rabbit model, the effect of two different doses of vigabatrin (VGB) on retinal function and morphology. Methods  Twenty-nine rabbits of mixed strain were divided into two groups, receiving either high-dose (n = 15) or low-dose (n = 14) oral VGB treatment (cumulative dose 29.8 ± 2.9 g and 14.2 ± 0.6 g respectively). Ten rabbits receiving water served as control animals. The rabbits underwent three baseline ff-ERG measurements before initiation of VGB medication and two ff-ERG registrations during treatment, after 8 and 12–14 weeks respectively. At the end of the study, the expression of protein kinase C-alpha (PKC-alpha), gamma amino butyric acid (GABA) A receptors, vimentin, glial fibrillary acidic protein (GFAP) and peanut agglutinin (PNA) was examined in retinal sections from all rabbits. Results  In animals of the high-dose group, the ff-ERG measurements revealed a significant decrease of isolated rod b-wave amplitudes, combined rod-cone b-wave amplitudes and amplitudes of oscillatory potentials (OPs); OP1, OP2 and OP3. In the low-dose group, the b-wave amplitudes of combined rod-cone responses as well as OP2 and OP3 were significantly reduced. PKC-alpha labeling demonstrated a dose-related translocation of the enzyme in rod bipolar cells, also revealing a significant decline of the number of PKC-alpha labeled rod bipolar cells in treated animals. Vimentin labeling showed a dose-related deviant labeling pattern of Müller cells, with strikingly low labeling intensity in the outer parts of the cells; in the outer limiting membrane (OLM) as well as the outer nuclear layer (ONL). Labeling with antibodies against GABA A receptors and GFAP, as well as PNA staining, revealed no differences between treated animals and controls. Conclusions  In this study, VGB medication was associated, in a dose-related manner, with a decrease of ff-ERG amplitudes as well as with altered protein expression in rod bipolar cells and Müller cells, suggesting alterations of inner retinal function. The dose-related morphological and electrophysiological changes indicate a retinal pathology that may explain the constricted visual fields seen in some patients treated with VGB. The authors have no financial interest in the material presented, and none of the authors has any conflict of interest to disclose. The authors have full control of the primary data, and agree to allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review the data upon request.