视网膜电图检测对视网膜静脉阻塞视功能的评价

目的 探讨视网膜电图（ｅｌｅｃｔｒｏｒｅｔｉｏｇｒａｍ,ＥＲＧ）的检测对视网膜静脉阻塞（ｒｅｔｉｎａｌ ｖｅｉｎ ｏｃｃｌｕｓｉｏｎ,ＲＶＯ）视功能评价的可能性。方法 对２１例ＲＶＯ患者及２３例正常对照组分别进行ＥＲＧ检测,测ａ、ｂ波振幅、峰潜时和振汤电位振幅。结果 ＲＶＯ组最大反应ａ、ｂ波振幅对照组明显下降,峰潜时延长、振荡电位幅值也明显降低,ＣＲＶＯ与ＢＲＶＯ组间有显著差异,说明随病变程度而加     

中心性浆液性脉络膜视网膜病变PERG和PVEP的研究

目的：观察中心性浆液性脉络膜视网膜病变（中浆）的图形视网膜电图（ＰＥＲＧ）和图形视诱发电位（ＰＶＥＰ）的表现。方法：检查９２例（１２０眼）正常人、５１例（５２眼）中浆患者的ＰＥＲＧ和ＰＶＥＰ。结果；患眼的ＰＶＥＰ的Ｐ１００潜伏期和ＰＥＲＧｂ波潜伏期延长，ＰＶＥＰ的Ｐ１００振幅ＰＥＲＧ的ｂ波振幅降低，中浆病情重，视力下降明显者，ＰＶＥＰ和ＰＥＲＧ的潜伏期改变最明显。结果：中浆患者的ＰＥＲＧ和ＰＶＥＰ     

复杂性视网膜脱离暗视视网膜电图的研究

目的 研究ＥＲＧ与孔源性视网膜脱离的关系及了解其预测ＰＶＲ形成的可能性及程度。方法 对４３例孔源性视网膜脱离伴ＰＶＲ患者手术前后分别行全视野暗视ＥＲＧ检查。结果 患者ＰＶＲ不同程度组ＥＲＧ的ａ、ｂ波振幅较正常眼降低,潜伏期延长;ＰＶＲ程度愈重,ＥＲＧ呈熄灭型所占比例愈大;ＥＲＧ振幅的降低与视网膜脱离的范围及持续时间有关;术后随着视网膜复位,ＥＲＧ明显改善。结论 复杂性视网膜脱离患者ＥＲＧ异常,并随ＰＶＲ程度加重异常更明显,指导临床上及早行ＥＲＧ检测,尽量减少ＰＶＲ的形成提供依据。     

视电生理对视网膜静脉阻塞分型的临床意义

本文观察了３２例视网膜静脉阻塞病人患眼（静脉郁滞性视网膜病变与缺血性视网膜病变）与对侧健眼的暗视ＥＲＧ及振荡电位。发现（１）ｂ波波幅及ｂ／ａ值患眼较对侧眼显著下降，且ｂ波峰时值明显延长。（２）ＯＰＳ各波幅患眼较对侧眼显著下降，Ｏ１，Ｏ２，Ｏ４峰时值明显延长。（３）ＨＲ型较ＶＳＲ型ｂ波波幅及ｂ／ａ波波幅比值显著下降。（４）ＨＲ型较ＶＳＲ型Ｏ１，Ｏ２波幅值显著下降。这些对判断ＲＶＯ分型有价值，对不能行     

中心性浆液性脉络膜视网膜病变PERG和PVEP的研究

目的：观察中心性浆液性脉络膜视网膜病变（中浆）的图形视网膜电图（ＰＥＲＧ）和图形视诱发电位（ＰＶＥＰ）的表现。方法：检查９２例（１２０眼）正常人、５１例（５２眼）中浆患者的ＰＥＲＧ和ＰＶＥＰ。结果：患眼的ＰＶＥＰ的Ｐ１００潜伏期和ＰＥＲＧｂ波潜伏期延长，ＰＶＥＰ的Ｐ１００振幅和ＰＥＲＧ的ｂ波振幅降低，中浆病情重、视力下降明显者，ＰＶＥＰ和ＰＥＲＧ的潜伏期均延长明显，波幅亦下降明显。四个观察指标中，以Ｐ１００潜伏期改变最明显。结论：中浆患者的ＰＥＲＧ和ＰＶＥＰ均有改变，有时较视力更敏锐，可客观反映中浆患者的视功能，检查以ＰＶＥＰ更为简便有效。     

视电生理对视网膜静脉阻塞分型的临床意义

本文观察了３２例视网膜静脉阻塞病人患眼（静脉郁滞性视网膜病变与缺血性视网膜病变）与对侧健眼的暗视ＥＲＧ及振荡电位。发现①ｂ波波幅及ｂ／ａ值患眼较对侧眼显著下降，且ｂ波峰时值明显延长。②ＯＰＳ各波幅患眼较对侧眼显著下降，Ｏ１、Ｏ２、Ｏ４峰时值明显延长。③ＨＲ型较ＶＳＲ型ｂ波波幅及ｂ／ａ波波幅比值显著下降。④ＨＲ型较ＶＳＲ型Ｏ１、Ｏ２波幅值显著下降。这些对判断ＲＶＯ分型有价值，对不能行荧光造影者，以及早期治疗、预后判断有重要临床意义。     

结晶样视网膜变性的视觉电生理改变探讨

目的探讨结晶样视网膜变性的视觉电生理改变。方法采用眼电图（ＥＯＧ）和视网膜电图（ＥＲＧ）检测１４例２８眼结晶样视网膜变性患者（病例组）和１５例３０眼正常人（对照组）、观察指标：（１）ＥＯＧ的基值电位（ＢＶＰ）、暗谷电位（ＤＴＰ）、暗谷时间（ＤＴＴ）、光峰电位（ＬＰＰ）、光峰时间（ＬＰＴ）、ＱＡｒ－ｄｅｎ、ＱＧｌｉｅｍ、（２）暗适应和明视ＥＲＧａ、ｂ波振幅、峰时值。采用ｔ检验对上述各项指标做两组间比较分析。结果病例组ＥＯＧ的ＢＶＰ、ＤＴＰ、ＬＰＰ、ＱＡｒｄｅｎＱＧｌｉｅｍ均较对照组明显降低,峰两组间有极显著性差异（Ｐ＜０．０１）;而ＥＯＧ的ＤＴＴ、ＬＰＴ与对照组比无明显改变,两组间无显著性差异（Ｐ＞０．０５）。病例组暗适应和明视ＥＲＧａ、ｂ波振幅、峰时值较对照组均有明显改变,两组间有极显著性差异（Ｐ＜０．０１）;但在２例早期患者中,其ＥＲＧａ、ｂ波振幅、峰时值均在正常范围。结论ＥＯＧ、ＥＲＧ作为客观定量的视功能检查方法,可为结晶样视网膜变性的视网膜功能损害程度提供客观指标。对结晶样视网膜变性早期患者ＥＯＧ可能较ＥＲＧ更具诊断价值。     

视网膜电图对视网膜血管阻塞的功能评估

目的：用视网膜电图评估视网膜血管阻塞的功能改变。方法：３０例视网膜中央静脉阻塞,１５例视网膜分支静脉阻塞,７例视网膜中央动脉阻塞和６例视网膜分支动脉阻塞按照ＩＳＣＥＶ的ＥＲＧ标准进行全视野网膜电图的检测。用Ｉ１蓝光、Ｉ１６红光和Ｉ１６白光估计暗视ＥＲＧ,用Ｉ１６红光和Ｉ８白光估计明视ＥＲＧ。记录ａ波和ｂ波的振幅和潜伏期及震荡电位。结果：视网膜血管阻塞的震荡电位异常率最高,其次为ｂ波;ＥＲＧ的异常率     

视网膜色素变性的多焦视网膜电图

目的研究视网膜色素变性（ＲＰ）的多焦视网膜电图（ＥＲＧ）特性和评价多焦ＥＲＧ应用价值。方法检测了 １２例（２４眼）ＲＰ患者的多焦 ＥＲＧ,测试野为２６．６°×２２．１°,记录 １０３个部位的反应,同时检测全视野 ＥＲＧ。结果ＲＰ眼在各个环的ａ波和ｂ波潜伏期、ｂ波振幅密度和振幅之和均较正常值有显著延长和降低（Ｐ＜０．０５或Ｐ＜０．０１）。５０％患眼在第１环可记录到潜伏期正常、振幅密度和总和均降低的ｂ波,而７５％患眼的全视野ＥＲＧ呈平坦反应。结论 多焦ＥＲＧ能更有效地评价ＲＰ的黄斑区功能。     

早期原发性开角型青光眼彩色图形视觉电生理改变分析

目的 探讨早期原发性开角型青光眼彩色图形视网膜电图（ＣＰ－ＥＲＧ）,彩色图形视觉诱发电位（ＣＰ－ＶＥＰ）的改变特征。方法 采用电生理方法记录早期原发性开角型青光眼（ＰＯＡＧ）患者在白／黑、红／黑、蓝／黑翻转图形刺激下的ＣＰ－ＥＲＧ、ＣＰ－ＶＥＰ,结果 （１）ＰＯＡＧ组ＣＰ－ＥＲＧ的ｂ波幅值下降,潜伏期延长;ＣＰ－ＶＥＰ的Ｐ１００波幅值下降,潜伏期延长;（２）ＰＯＡＧ组ＣＰ－ＥＲＧ和ＣＰ－ＶＥＰ的异     

视网膜电图在视网膜中央静脉阻塞分型中的应用价值

我们选择不同的刺激条件，对32例早期视网膜中央静脉阻塞(central retinal vein occlusion,CRVO)患者进行视网膜电图(electroretinogram,ERG)的检测．缺血型CRVO13例的a、b波潜伏期延长，b波振幅明显下降：非缺血型CRVO19例的a、b波潜伏期延长，b波振幅表现为轻度降低、升高或正常．提示b波振幅和b/a是区分缺血型与非缺血型CRVO的最敏感指标．我们还探讨了ERG在早期CRVO分型中的应用价值。 （中华眼底病杂志，1994，10：7-10）     

Electroretinogram b/a wave ratio improvement in central retinal vein obstruction.

The electroretinogram (ERG), especially the b/a wave ratio, is considered a good indicator of retinal ischaemia in central retinal vein obstruction (CRVO). Seven CRVO patients who showed b/a wave ratio improvement from < 1.0 [negative type (-) ERG] to > or = 1.0 and one from 1.07 to 1.53 were studied. Three mechanisms of change were observed: firstly, the b-wave amplitude increased without an a-wave amplitude decrease (group A, n = 2); secondly, the b-wave amplitude increased with an a-wave amplitude decrease (group B, n = 4); and, thirdly, both decreased, but the a-wave amplitude decreased more markedly (group C, n = 2). In group A, the visual acuities improved markedly. In group B, the visual acuities improved in two cases in which the b-wave amplitude reached the normal range; the visual acuities did not improve in two cases in which the b-wave amplitude did not reach the normal range. In group C, the visual acuities remained poor. The negative (-) ERG or significantly reduced b/a wave ratio is associated with ischaemic CRVO and did not occur because of the filtering effect of the haemorrhage, which may reduce the stimulus light for the ERG. Improvement of the reduced b/a wave ratio with an increased b-wave amplitude was accompanied by improvements in fundus appearance and visual acuity in CRVO. The results suggest that the retinal ischaemia in CRVO, as revealed by the ERG and fluorescein angiogram, may be reversible in some cases.     

虹膜荧光素血管造影在虹膜新生血管诊断中的应用

目的 探讨虹膜荧光素血管造影(IFA)在缺血性视网膜中央静脉阻塞(CRVO)虹膜新生血管(NVI)诊断中的价值.方法 经荧光素眼底血管造影(FFA)检查确诊的CRVO患者51例51只眼纳入研究.所有患者均行视力、裂隙灯显微镜检查、眼前节彩色照相、眼压及FFA+IFA检查.根据FFA检查结果分为非缺血性和缺血性CRVO,分别为20、31只眼.非缺血性CRVO20只眼中,男性11只眼,女性9只眼;年龄41～59岁.缺血性CRVO31只眼中,男性21只眼,女性10只眼;年龄28～62岁.采用德国海德堡眼底荧光血管造影仪进行FFA+IFA检查,将典型图像存入计算机图像处理系统进行分析.对比观察裂隙灯显微镜和IFA NVI的检出率.缺血性CRVO31只眼均行全视网膜激光光凝(PRP)治疗,其中,完成治疗27只眼,未坚持完成治疗4只眼.完成治疗后6个月,随访观察NVI消退情况.结果 非缺血性CRVO20只眼裂隙灯显微镜检查瞳孔缘及虹膜未见新生血管,占100.0%;IFA检查虹膜未见显影,呈色素遮蔽荧光,占100.0%.缺血性CRVO31只眼中,裂隙灯显微镜检查显示瞳孔缘及虹膜有细小新生血管13只眼,占41.9%;IFA检查显示NVI 23只眼,占74.2%.2种检查方法NVI检出率比较,差异有统计学意义(Z=-3.425,P=0.001).IFA检查NVI分别表现为小团状、细线状或不规则交叉网状强荧光染色及渗漏.完成PRP治疗的27只眼IFA检查结果显示,瞳孔缘及虹膜表面未见荧光染色及渗漏;未坚持完成PRP治疗4只眼,1～2个月后出现新生血管性青光眼(NVG).结论 IFA可以提示眼前节的缺血状态,具有较高的特异性,辅助CRVO缺血型早期诊断,预测是否发展NVG.

Abstract：

Objective To evaluate the application value of iris fluorescein angiography (IFA) in the diagnosis of ischemic center retinal vein occlusion (CRVO). Methods Fifty-one patients (51 eyes) with CRVO which had been diagnosed by fundus fluorescein angiography (FFA) were studied. All patients underwent the examination of visual acuity, slit lamp biomicroscope, anterior segment color photography,intraocular pressure, FFA and IFA. The patients were classified as non-ischemic CRVO (20 eyes) and ischemic CRVO (31 eyes). The 20 non-ischemic CRVO patients included 11 males and nine females, aged from 41 to 59 years. The 31 ischemic CRVO patients included 21 males and 10 females, aged from 28 to 62 years. FFA and IFA were performed for all the patients using Heidelberg retina angiograph, and the classic pictures were analyzed by the computer image processing system. The detection rate of iris neovascularization (NVI) by slit lamp biomicroscope and IFA was analyzed. All ischemic CRVO eyes underwent panretinal photocoagulation (PRP), and PRP was completed in 27 eyes and not completed in four eyes. Six months after PRP the regression of iris NVI was followed up. Results All non-ischemic CRVO eyes (100. 0% ) had no neovascularization on papillary margin and iris by slit lamp biomicroscopy, and had no fluorescence (pigment blocked fluorescence) on IFA. Thirteen eyes (41.9%) and 23 eyes (74.2%) of the 31 ischemic eyes had NVI by slit lamp biomicroscope and IFA, respectively. The NVI detection rate of those two methods was statistically different (Z= - 3. 425, P = 0. 001 ). NVI showed strong fluorescence and leakage with variable patterns (small blocks, thin lines and irregular cross-links) by IFA. There was no fluorescence staining and leakage on papillary margin and iris in 27 eyes who completed the PRP, but the neovascular glaucoma (NVG) occurred in one eyes who discontinued the PRP treatment after one to two months. Conclusions IFA has a high specificity in CRVO which hints the ischemic state of anterior segment. It is helpful to the early diagnosis of ischemic CRVO and the turnover of NVG.     

Electroretinogram b-wave implicit time and b/a wave ratio as a function of intensity in central retinal vein occlusion.

The ability of electroretinogram (ERG) b-wave implicit time and b/a wave ratio to predict iris neovascular response was analyzed as a function of stimulus intensity over a 3.6 log unit intensity range in 39 patients with central retinal vein occlusion (CRVO). Predictive power for CRVO patients was evaluated using ROC area at intensities of 1.23, 1.83, 2.43, and 3.03 effective log quanta/rod, where reliable data for both parameters were obtainable from most patients. The relative predictive power of b-wave implicit time and b/a wave ratio were shown to vary with stimulus intensity. The predictive power of b-wave implicit time, as measured by ROC area, declined to below significance at high intensity (above 1.83 log quanta/rod), while b/a wave ratio performed best at middle intensities (1.83 and 2.43 log quanta/rod) and not as well at high and low intensities. Further analysis of statistical behavior of both ERG parameters was obtained from the t statistic. Insight into the mechanism influencing predictive power of b-wave implicit time was derived from measurements on normal adults and CRVO patients with response data taken at high intensities. These results suggest that an optimal stimulus intensity range can be found for these ERG parameters in the evaluation of CRVO.     

视网膜静脉阻塞患者视力预后相关因素分析

目的研究各型视网膜静脉阻塞患者的视力预后、并发症及视力降低的相关因素.方法视网膜静脉阻塞患者913例(944只眼),年龄15～89岁,平均(52.8±11.9)岁;平均随访时间20.7个月.患者所有临床资料均输入计算机,应用SPSS软件进行统计学处理.结果 (1)按部位分型总干阻塞406只眼,占43.0%;半侧阻塞60只眼,占6.4%;分支阻塞478只眼,占50.6%.(2)按缺血分型944只眼中,缺血型633只眼,占67.1%;非缺血型311只眼,占32.9%.(3)患者视力预后各型静脉阻塞患者治疗前、后视力比较,总干阻塞和半侧阻塞的差异无显著性(t=1.45,1.62;均P>0.05),分支阻塞的差异有显著意义(t=7.89,P<0.05).(4) 患者初诊视力水平与预后3种类型静脉阻塞患者视力预后均差;患者的初诊视力水平均与视力预后密切相关(χ2=175.261,21.357,106.408;均P<0.01).(5) 静脉阻塞导致的低视力和盲目率各型静脉阻塞患者的低视力与盲目率比较,差异有显著意义(χ2=85.251,P<0.01).(6) 缺血型与非缺血型患者视力预后比较视网膜静脉总干阻塞、半侧阻塞、分支阻塞患者中缺血型与非缺血型比较,差异均有显著意义(χ2=157.819,19.637,56.737;P<0.01).(7)导致静脉阻塞的危险因素高血压占57.8%,动脉硬化占67.4%,血液黏稠度增高占24.6%,原发性青光眼占1.5%,糖尿病占6.2%.(8) 静脉阻塞患者并发症的发生率黄斑囊样水肿占46.7%,视网膜和(或)视乳头新生血管占21.5%,玻璃体出血占11.4%,新生血管性青光眼占4.2%.其中总干阻塞发生新生血管性青光眼39只眼,占总干阻塞的9.6%,占半侧阻塞的1.7%.(9)并发症导致的低视力和盲目率低视力者中,黄斑囊样水肿占37.9%,新生血管占29.9%;盲目者中,黄斑囊样水肿占19.5%,新生血管占23.0%.新生血管性青光眼导致的盲目者中,视力<0.05者占95.0%.结论视网膜静脉阻塞的致盲率较高,影响视力预后的最重要因素是缺血型视网膜静脉阻塞.初诊视力水平与视力预后关系密切,黄斑囊样水肿、新生血管及新生血管性青光眼为致盲的重要原因.     

Central retinal vein occlusion in a young patient with seropositive syphilis

Central retinal vein occlusion (CRVO) is a common retinal vasculopathy typically affecting adults in the fifth to seventh decade of life. Systemic disease, particularly hypertension, is often a contributing factor in this sight-threatening condition. CRVO in young adults, however, is an uncommon occurrence with relatively few reported cases in the ophthalmic literature. Two studies performed on young adults (less than 40 years of age) presenting with CRVO revealed that, in most cases, there was not a strong correlation with hypertension or other systemic diseases. In more severe cases, namely those with poor visual outcome from the ischemic type of CRVO, there was a strong correlation with cardiovascular disease and diabetes mellitus. Systemic inflammatory conditions represent a small contributing factor in patients presenting with CRVO. This paper reports on a 21-year-old female with non-ischemic CRVO who was serologically positive for syphilis.     

视网膜中央静脉阻塞与阻塞性睡眠呼吸暂停综合征的相关性

目的　探讨视网膜中央静脉阻塞(central retinal vein occlusion,CRVO)与阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)的相关性。方法　选择CRVO组患者及非CRVO患者（对照组）各24例进行研究。采用多导睡眠呼吸记录仪在夜间对CRVO患者及对照组的呼吸暂停低通气指数(apnea-hypopnea index，AHI)、夜间平均最小氧饱和度等指标进行监测。根据AHI对OSAS进行诊断。对两组的OSAS发生率、AHI、夜间平均最小氧饱和度、年龄、体质量指数(body mass index,BMI)等进行比较。结果　CRVO组BMI（25.49±4.17）kg·m^-2和AHI（18.89±14.54）与对照组［BMI:(22.57±5.25)kg·m^-2、AHI:8.25±6.98］相比均明显升高，而CRVO组夜间平均最小氧饱和度（80.04±11.63）%与对照组（89.14±7.22）%相比明显降低，差异均有统计学意义（均为P<0.05）。其中，CRVO组OSAS患病率为75.00%，显著高于对照组（37.50%），差异有统计学意义（P<0.05）。OSAS组［年龄（59.67±9.32）岁、BMI(27.59±5.19)kg·m^-2和AHI (21.16±12.08)］与非OSAS组［年龄（53.31±7.04）岁、BMI（22.15±4.94）kg·m^-2、AHI（3.76±1.13）］相比均明显升高，而患者夜间平均最小氧饱和度（81.42±6.61）%与非OSAS组（87.08±5.77）%相比明显降低，差异均有统计学意义（均为P<0.05）。13例非缺血型CRVO患者中有OSAS 11例（84.62%），11例缺血型CRVO患者中有OSAS 7例（63.64%），OSAS在非缺血型及缺血型CRVO患者中的患病率差异无统计学意义（P>0.05）。结论　CRVO患者中OSAS的患病率较高，提示OSAS在CRVO的发病进程中起重要作用或者是CRVO发病的使动因素。     

视网膜电图明视负向反应在视网膜静脉阻塞中的变化

目的 观察视网膜静脉阻塞(RVO)患者视网膜电图(ERG)明视负向反应(PhNR)的变化特点.方法 对间接检眼镜、荧光素眼底血管造影(FFA)检查确诊的RVO患者30例30只患眼以及对侧健康眼进行视力、视野、闪光ERG(FERG)检查,同时选取与其性别、年龄相匹配的正常人25例50只眼作为正常组进行FERG检查.所有检查均按常规方法进行.RVO患者中,视网膜中央静脉阻塞(CRVO)患者14例14只眼、视网膜分支静脉阻塞(BRVO)患者16例16只眼.根据其病史及FFA检查结果,将其按病程时间划分为小于1个月、1～3个月、大于3个月组;另外再根据RVO分型标准及具体检查结果,将RVO患者分为缺血型和非缺血型.对比分析RVO患眼与对侧健康眼以及正常眼PhNR振幅变化及ERG其他参数指标,包括振荡电位(Ops),视锥细胞反应(Cone-a、Cone-b),视杆细胞反应(Rod-b),暗适应眼的最大反应(Max-a、Max-b),30 Hz闪烁光反应(30 Hz)的差异以及PhNR振幅变化与RVO疾病缺血类型、病程的关系.结果 PhNR振幅在CRVO患眼为(28.20±5.80)μV,BRVO患眼为(36.96±4.71)μV,对侧健眼为(61.25±3.93)μV,正常眼为(59.33±16.92)μV.CRVO组与对侧健眼、正常组比较,差异有统计学意义(F=10.69,9.80;P＜0.001),BRVO组与对侧健眼、正常组比较,差异有统计学意义(F=9.69,9.75;P＜0.001).CRVO组中缺血型PhNR值为(22.77±5.73)μV,非缺血型为(36.63±12.91)μV,二者差异有统计学意义(t=6.54,P＜0.01);BRVO组缺血型PhNR值为(32.39±13.22)μV,非缺血型为(46.73±10.43)μV,二者差异无统计学意义(t=2.12,P＜0.05);病程小于1个月组CRVO与BRVO分别为(24.58±4.60)、(27.94±15.73)μV,1～3个月组分别为(50.39±13.80)、(58.69±12.43)μV,大于3个月组为(25.40±19.94)、(34.48±16.72)μV,CRVO中1～3个月组与大于3个月组差异有统计学意义(F=4.30,P＜0.01).结论 RVO患眼的PhNR振幅较对侧健康眼以及正常对照眼明显降低,缺血型较非缺血型降低,随病程变化呈现下降、上升、下降的变化趋势.     

Transient increased retinal hemorrhage and the retinal venous blood flow change in the course of non-ischemic central retinal vein occlusion treated with an anticoagulant

PURPOSE: To investigate transient increased retinal hemorrhage during anticoagulant therapy and changes in the retinal venous blood flow in the course of non-ischemic central retinal vein occlusion (CRVO). METHODS: Seventeen patients(eighteen eyes) with non-ischemic CRVO were studied. The retinal vein diameter, blood velocity, and blood flow were determined by the laser Doppler method in seven patients. RESULTS: The retinal hemorrhage increased in nine eyes (50%); however, the retinal hemorrhage was transient and it finally decreased without vision loss in seven of the eyes. The retinal hemorrhage increased in the other two eyes and they became ischemic. The vessel diameter decreased and both velocity and blood flow increased in six of the seven patients two weeks after the treatment. There was no significant change in blood flow in cases which showed a transient increase in retinal hemorrhage, and they did not show a decrease in vision; however, only one eye which became ischemic showed a decrease in blood flow. CONCLUSION: We can judge whether an increase in retinal hemorrhage is transient or the clinical condition is getting worse in an early stage by measuring the retinal vein blood flow quantitatively by laser Doppler flowmetry.     

The variability of the b-wave of the electroretinogram with stimulus luminance

We measured the variability of the b-wave of the electroretinogram as a function of stimulus luminance in two young normal individuals. We also estimated b-wave variability by examining residuals from Naka—Rushton curves fit to intensity-response data. The change of variability with amplitude was similar with both techniques. The standard deviation of b-wave amplitude rose with b-wave amplitude at low stimulus intensities. At higher intensities, the standard deviation of b-wave amplitude became constant. The point at which the standard deviation became constant was LogK for the eye, as determined by fitting the data with the Naka—Rushton equation. These changes suggest that the mechanisms underlying the growth of the b-wave with luminance change near LogK.Abbreviations CRVO central retinal vein occlusion - PMR photomyoclonic reflex