后天性内斜视晚期手术对视觉诱发电位的影响

目的 探讨不伴有弱视的后天性内斜视患者5岁以后行内斜矫正术,术后3个月VEP（Visual Evoked Potential）的变化.方法 不伴有弱视的后天性内斜视34例,正常儿童30例.于术前及术后3个月分别记录双眼及单眼刺激时全视野刺激VEP及不同空间频率（85′、21′）P100的潜伏时和振幅.结果 后天性内斜视组术后3个月VEP与术前相比,振幅值增加,二者之间差异有显著性意义（P＜0.05）.而潜伏期改变不明显,二者之间差异无显著性（P＞0.05）.术后3个月与术前相比,临床检查双眼视功能有所改善.结论 尽管在临床视觉发育期后行内斜矫正术,仍会对双眼VEP有明显的影响,而且对改善双眼融合功能有益.     

内斜视患者的双眼图形视诱发电位研究

目的：了解内斜视患者双眼图形视诱发电位的特点以及其与视觉抑制的关系。方法：正常对照组28例,共同性内斜视20例。用《立体视检查图》检查两组的红绿抑制试验及立体视锐度。视诱发电位图形刺激采用棋盘格翻转形式,频率2Hz,方格大小0．77（视角48．125′）,在不同的对比度下（50％与70％）记录右、左及双眼的图形视诱发电位的振幅峰时、B／M和BL／Lmin比值。结果：斜视组中85％红绿抑制试验阳性,正常 与内斜视组在50％与70％对比度下的P100单眼振幅、双眼振幅及其B／M比值差异均存在显著性意义。在50％的BL／Lmin比值下,两组差异亦存在显著性意义,这种差异主要由于斜视组P100单眼最小峰时与双眼峰时明显不同所致。结论：内斜视患者双眼振幅与峰时明显不同于正常对照组,这种异常与内斜视存在视觉抑制有关。     

内斜视儿童双眼视VEPs的研究

目的研究内斜视对儿童双眼视及ＶＥＰｓ双眼总和的影响。方法对４７名正常儿童及２５名不伴有弱视的内斜视儿童进行全视野刺激多导视觉诱发电位的研究。结果正常儿童组双眼刺激视觉诱发电位与单眼刺激视觉诱发电位相比，双眼刺激Ｎ７５、Ｐ１００潜伏期较短而Ｎ７５－Ｐ１００波幅较大，表明该年龄组儿童双眼视已发育成熟；但内斜视组双眼刺激与单眼刺激ＶＥＰｓ波幅、潜伏期无显著性差异，并且内斜视组双眼总和低于正常组，尤其是内斜视组中同视机检查无同时视者双眼总和明显低于正常组。结论在不伴有弱视的情况下，内斜视仍是损害双眼视功能的重要因素，即破坏双眼同时视，形成单眼抑制。同时证明视觉诱发电位双眼总和能够客观评价：在分视状态下，有无单眼抑制     

后天性共同性内斜视手术治愈后的双眼视觉

目的：探讨后天性共同性内斜视手术治愈后双眼视觉的恢复规律。方法：对40例后天性共同性内斜视经手术治愈后患者的临床资料进行分析。结果：40例后天性共同性内斜视患者术前36例(90％)无双眼视觉。术后40例(100％)具有同时知觉能力，40例(100％)可获得融合功能，但融合范围低于正常人群，26例(65％)获得远立体视，18例(45％)获得不同程度的近立体视。结论：后天性共同性内斜视患者黄斑中心凹立体视损害最严重，对于后天性共同性内斜视的临床处理应更加积极，树立婴幼儿期的持续性内斜应急诊处理的观念，使更多患儿获得良好的立体视觉。     

屈光性调节性内斜视的双眼视觉

报告１２０例屈光性调节性内斜视（ＲＡＥＴ）的双眼视觉。经平均随访７６年后，３６％的ＲＡＥＴ患者失去了双眼单视功能。双眼单视功能的丧失与斜视发病年龄，弱视治疗效果及双眼视力参差大小有关。斜视发病年龄到戴镜正位的间隔时间，屈光状况及双眼间屈光参差≥１５０Ｄ的比率与双眼视觉无关。发生眼位回退，合并垂直斜视与原发性下斜肌功能亢进者容易破坏双单眼视功能。提出及时确诊，积极治疗弱视和对已发生眼位回退与合并垂直斜视，原发性下斜肌功能亢进的患者及时手术治疗是提高ＲＡＥＴ功能治愈的关键。     

后天性固定性内斜视临床分析

后天性固定性内斜视临床分析刘双珍吴小影夏晓波谭浅湖南医科大学湘雅医院眼科（４００００８）后天性固定性内斜视临床上少见，我院收治６例，随访６—２４个月，５例容貌改善，取得良好效果，现介绍如下：１．一般资料：本组系１９９５年２月至１９９７年２月住院病例共...     

外斜视儿童的视觉诱发电位双眼总和

本文对外斜视儿童ＶＥＰｓ的双眼总和（ＶＥＰＢＳ）进行了探讨。测试不伴有弱视的外斜视儿童３９名。结果显示，恒定性外斜组及间歇性外斜组的ＶＥＰＢＳ较正常对照组减小（Ｐ＜０．０１），ＶＥＰｓ的ＶＥＰＢＳ减小与眼位偏斜有关；恒定性外斜组ＶＥＰＢＳ小于间歇性外斜组（Ｐ＜０．０１），该结果与临床双眼视功能检查结果一致。     

弱视儿童双眼总和视觉诱发电位变化的研究

目的 探讨弱视儿童双眼视功能及总和VEP反应特点,评估总和VEP反应对双眼视觉功能检测意义.方法 选取正常儿童80名、远视性弱视儿童151例,进行双眼总和VEP检查,统计学分析总和VEP反应特点.结果 弱视组儿童总和VEP反应低于正常对照组;无同时视者与有同时视者之间总和VEP比较有显著差异.结论 总和VEP反应作为一种客观指标,可以反映弱视儿童的双眼视功能状况,对其双眼视功能的评价具有一定的价值.     

弱视儿童双眼总和视觉诱发电位变化的研究

目的探讨弱视儿童双眼视功能及总和图形视觉诱发电位（P-VEP）反应的特点,评估总和P-VEP反应对双眼视觉功能检测的意义。方法选取80名正常儿童和在南昌大学附属第二医院儿童眼科确诊的远视性弱视儿童151例,进行双眼总和P-VEP检查,分析总和P-VEP反应的特点。正常儿童与弱视儿童的人口基线学特征经统计学分析差异无统计学意义。P-VEP检查方法和刺激条件的选择参照吴乐正等的方法,记录电极的放置按照视觉电生理国际标准化的要求。视力检查采用国际标准视力表,双眼视觉功能检查采用Titmus立体图、同视机三级画片。P-VEP检测结果以双眼反应/单眼反应（B/M）比值作为评价指标。结果弱视组儿童总和P-VEP反应低于正常对照组（t=10.75,P〈0.01）;不同程度弱视组的B/M值随弱视的严重程度明显减低（F=10.93,P〈0.01）;无同时视者总和P-VEP与有同时视者比较,差异有统计学意义（t=7.835,P〈0.01）。结论总和P-VEP反应作为一种客观指标,可以反映弱视儿童的双眼视功能状况,对其双眼视功能的评价具有一定的价值。     

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。     

The Parameters of Pattern Visual Evoked Potential in the Severe Visual Loss Patients in Korean

PurposeTo compare the characteristics of the pattern visual evoked potential (PVEP) in patients with severe visual loss and normal controls, and to demonstrate the range of PVEP parameters in normal Koreans.MethodsThe patients were divided into three groups according to visual acuity: group 1, ranging from no light perception to less than 0.02; group 2, ranging from 0.02 to 0.1; and group 3, ranging from 0.125 to 0.25. Group 4 was established as a healthy control group. The 95% confidence intervals (CIs) of the PVEP parameters were calculated for group 4. The PVEP parameters were compared among these four groups, and the amplitudes were evaluated with respect to the 95% CIs. We used the area under the curve to integrate the sensitivity and the specificity of the PVEP parameter quantitative values (7.01 to 9.57 µV and 6.75 to 10.11 µV).ResultsA total of 101 eyes were investigated. The 95% CIs of the P100 and N135 amplitudes of group 4 were 7.01 to 9.57 µV and 6.75 to 10.11 µV, respectively. The amplitudes of P100 and N135 were significantly higher in group 4 (p < 0.001). The P100 and N135 amplitude were below the 95% CI in all group 1 patients. The area under the curve of the P100 amplitude was the highest (0.789).ConclusionsNo legally blind patient in the present study exhibited a value within the 95% CI of the controls. The P100 amplitude may be the best parameter for defining blindness in patients.     

Clinical Characteristics and Surgical Effects of Type Ⅲ Acute Acquired Concomitant Esotropia

Objective: To investigate the clinical characteristics and surgical effects in type Ⅲ acute acquired concomitant esotropia (AACE Ⅲ). Methods: This was a retrospective self-control study. Thirty-one AACE Ⅲ patients, aged 14 to 39 years, who underwent routine strabismus surgery at the Affiliated Eye Hospital of Nanjing Medical University, were enrolled from July 2016 to July 2019. The following data were collected: Onset time, binocular ametropia, time of near work, the attachment point of the internal rectus muscle, pre- and postoperative deviation, fusion range, and distance and near stereopsis. The followup period ranged from 6 months to 12 months (7.4±2.6 months). A Wilcoxon signed rank test was used to compare the difference in esodeviation and binocular fusion range before and after strabismus surgery. Preand postoperative distance stereopsis were analyzed by the traditional paired Chi square test, while pre- and postoperative near stereopsis was analyzed by the enhanced paired Chi square test. Results: Among the 31 patients with AACE Ⅲ, 3 patients (10%) had high myopia, 25 patients (81%) had moderate myopia, 2 patients (6%) had low myopia, and only one patient (3%) had emmetropia. All patients had performed nearwork with an average time of 7.8±1.1 hours per day. The average distance between the attachment point of the internal rectus muscle and the corneal limbus was 4.9±0.1 mm. The median pre-operative esodeviation at near (33 cm) was 35 PD, and at distance (6 m) was 40 PD. The difference between them was statistically significant (Z=-3.136, P=0.002). In this study, all patients underwent a successful strabismus operation and at the time of the final follow-up, whether it was at 33 cm or 6 m, the median degree of postoperative strabismus was 0 PD. Compared with the pre-operative degree of strabismus at the same distance, the postoperative degree was significantly smaller (both Z=-4.865, both P<0.001). The median of pre- and postoperative binocular fusion range was 14° and 19°, respectively, and the difference between them was statistically significant (Z=-3.149, P=0.002). Compared with distance and near stereopsis before strabismus surgery, 16(84%) patients recovered distance stereopsis and 19(95%) patients recovered near stereopsis after the surgery. Both distance and near stereopsis significantly improved when comparing stereopsis before and after surgery. The difference was statistically significant (χ2 =14.063, 24.000, respectively; P<0.001, P=0.001, respectively). Conclusions: Prolonged near work, the forward attachment point of the internal rectus muscle and moderate myopia appear to be important risk factors for AACE Ⅲ. Strabismus surgery to establish the proper angle can significantly diminish the degree of esotropia and improve the binocular fusion range and stereopsis in AACE Ⅲ patients.     

Binocular Summation and Control of Intermittent Exotropia

Background: Binocular summation (BiS), or improvement in binocular vision exceeding the better eye alone, is affected by strabismus. Being easily measured, BiS may be a useful indicator for subjective outcomes like stereopsis in strabismus. This study aims to investigate the relationship between BiS and measures of control of intermittent exotropia (IXT). Methods: Patients with IXT were recruited before undergoing strabismus surgery and underwent tests of binocular and monocular high- and low-contrast visual acuity, stereopsis at distance and near, and Newcastle Control Score (NCS), a score developed by incorporating home control and clinic control criteria into a control rating scale. BiS was calculated using high-contrast Early Treatment of Diabetic Retinopathy Study (ETDRS) and Sloan low-contrast acuity charts (LCA) at 2.5% and 1.25% contrast as the difference between the binocular score and that of the better eye. The relationship between BiS and measures of IXT control (NCS and distance near stereoacuity disparity) was evaluated using a correlation analysis by Spearman correlation coefficients and the Kruskal-Wallis test. Results: Thirty-four patients were included (mean [± standard deviation (SD)] age 19±16 years) having a mean (±SD) of 26±16Δ IXT at distance and 20±16Δ at near. Mean (±SD) BiS for ETDRS and Sloan LCA at 2.5% and 1.25% was 0.8±3.6, 1.9±6.0, and -2.3±7.2, respectively. The Spearman correlation coefficient of BiS and NCS was -0.53 (95% CI -0.85 to -0.25) for 2.5% LCA and -0.43 (95% CI -0.77 to -0.13) for 1.25% LCA. BiS at 2.5% LCA (P=0.006) and at 1.25% LCA (P=0.029) significantly differed between the groups based on NCS score groupings (1-3, 4-6, and 7-9), with patients who had better control scores having higher levels of BiS. BiS did not differ significantly between patients grouped according to the difference between stereoacuity measured at near versus distance. Conclusion: Significantly lower low-contrast BiS in patients with higher NCS may suggest that decreased BiS is associated with less control in IXT. This finding suggests that BiS may reflect control in IXT across a population of patients with IXT.     

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.     

The Acute Effect of Cigarette Smoking on Pattern Visual Evoked Potentials

Reports of tobacco-induced electrocortical activation and decrements in ocular blood flow in the acute faze indicated that this effect is mediated via nicotin’s action or neuronal systems. In this study, pattern visual evoked potentials were investigated in a group of male smokers (22 right eyes of 22 subjects) in separate real smoking and sham smoking sessions. On each session, pattern visual evoked potentials were recorded before smoking, immediately after smoking, and five minutes after smoking. Latency and amplitude values for P100 peaks were assessed and analyzed in each smoking condition for both real smoking and sham smoking sessions. Real smoking significantly decreased P100 latency values (p value related to difference between pre-smoking and immediately after smoking conditions is 0.009) and increased P100 amplitude values (p value related to difference between pre-smoking and fifth minute after smoking is 0.039). Statistically no significant difference was observed in sham smoking sessions. Our results are consistent with smoking-induced stimulant effects on pattern visual evoked potentials.     

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。     

Flash Visual Evoked Potential as a Prognostic Factor for Vitreous Operations in Diabetic Eyes

In 116 diabetic eyes scheduled for vitreous surgery, the visual evoked potential (VEP) after flash stimulation was recorded prior to surgery. Latencies of the flash evoked potentials show a distribution suggestive of a Gaussian curve with an abnormal extension. Dividing the material into two groups based on a latency shorter or longer than 100 milliseconds revealed a highly significant difference in the visual improvement following surgery between patients with a short and patients with a long latency (P < 0.001). With a latency longer than 100 millisec. most patients showed no visual change after operation, and among the few who did the change, consisted more often in visual reduction than improvement. Additional investigations in the study reveal that it is likely that the prolonged latency of the flash VEP is due to pathology of the retina or visual pathways.     

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.