阿托品联合综合疗法治疗青少年屈光不正的疗效及安全性分析

目的:分析阿托品联合综合疗法治疗青少年屈光不正弱视的近期疗效及安全性。方法:以2017年2月至2017年5月于我院接受诊治的60例青少年屈光不正弱视患者(患眼102只)为研究对象,按接受诊治时间先后顺序分为对照组和观察组各30例。患眼分别为52和50只。观察治疗前后所有屈光不正弱视患者的视觉敏感度、图像诱发电位(P-VEP)、立体视功能的改善、治疗有效率和不良反应的发生情况。结果:治疗后,两组患眼对比度、波幅均较治疗前显著升高(P0.05),潜伏期低于治疗前(P0.05),且观察组各空间频率下的对比度、波幅均显著高于对照组(P0.05),潜伏期低于对照组(P0.05);观察组患眼的矫正幅度范围和矫正分开范围显著高于对照组,矫正近立体视锐角显著低于对照组(P0.05);观察组的治疗总有效率为92.00%,高于对照组的71.15%(P0.05);两组患者均未见明显的不良反应发生。结论:阿托品联合综合疗法对青少年屈光不正弱视的近期疗效较好,且安全性高。     

单眼远视性弱视儿童P-VEP检查的临床研究

目的:分析单眼远视性弱视儿童图形视觉诱发电位(P-VEP)检查情况,探讨外周发病机制,为临床诊疗提供依据。方法:选取2013年1月到2015年10月我院收治的单眼远视性弱视儿童75例(75只眼),另选取同期正常儿童32例(64只眼)为对照组,根据病情将弱视儿童分为轻度(A组)和对侧健眼组(B组),中度(C组)和对侧健眼组(D组),重度(E组)和对侧健眼组(F组),应用P-VEP检查各组P100波及振幅。结果:A组、C组、E组P100波潜伏期较B组、D组、F组和对照组延长(P0.05),振幅较B组、D组、F组和对照组降低(P0.05),A组、C组和、E组P100波潜伏期和振幅比较具有统计学意义(P0.05),B组、D组、F组P100波潜伏期与对照组无统计学意义(P0.05),B组、D组、F组振幅显著低于对照组(P0.05),B组、D组、F组P100波潜伏期和振幅比较无统计学意义(P0.05)。结论:单眼远视性弱视儿童弱视眼会出现P100波潜伏期延长,振幅降低,对侧健康眼会出现振幅降低。     

单眼睑缝合1周建立形觉剥夺性弱视猫模型

目的比较正常组、模型组及对照组的图形视觉诱发电位(PVEP)和扫描视觉诱发电位(SVEP)视力,研究各组的视觉电生理表现,探讨单眼睑缝合1周是否可以建立形觉剥夺性弱视模型。方法分析三组PVEP的波形变化、潜时及完成一次诱发反应的时间;比较各组由SVEP得出的客观视力。结果①正常组PVEP由2个波峰组成“M型”(正向波向上),模型组及对照组出现波的分离—波形由多个波组成,而且完成一次反应的时间延长。②缝合侧的N75延迟,SVEP视力较正常组差且差别有统计学意义。③对照组未缝合侧视力恢复到正常水平而缝合侧视力仍差且与正常组有统计学差异。结论短期形觉剥夺的视觉电生理变化是弱视猫的一种表现,单眼睑缝合1周即可建立形觉剥夺性弱视猫的模型。     

正常人眼的多焦视诱发电位特征

研究31只正常眼视野中央8.6度的多焦（多刺激野）视诱发电位(multifocal visual evoked potential, MVEP)在视野各部位的特征.观察到平均反应密度随离心度增加而减少,并且在下半视野比在上半视野相应部位高;在上半视野,MVEP波形的极性反转发生率较高.MVEP在视野中的改变反映了视网膜和大脑视皮层解剖特征及其拓扑投射关系.     

诱发电位的检测及其应用

诱发电位(EVOKED POTENTIAL)是从放置在头皮上、皮肤上或者压迫在末梢神经上面的表面电极记录到的,由外加一定方式的刺激进行诱导而产生的生物电响应。目前,诱发电位作为一种非侵入性检查神经系统功能的手段,已广泛地用于临床诊断、大脑及脊柱功能研究和病人监护等方面。诱发电位常常还能揭示出一般手段所不能检测的神经系统功能障碍。已经证实,诱发电位在检测弱视、听觉通路损伤、昏迷、呆痴、脱髓鞘疾病、颅内肿瘤、头部创伤、视神经炎、末梢神经损伤、视网膜机能失调、中风、脑干评     

内斜弱视猫的视觉诱发电位

内斜弱视猫的视觉诱发电位蔡浩然,周毅丁,李少敏,王伟（北京医科大学儿童视觉研究中心１０００３４）用棋盘格翻转和平面均匀光作刺激,研究了三只实验性内斜视模型猫的多导程视觉诱发电位（ＶＥＰｓ）。实验动物是在生后２０天行左眼外直肌切除术,然后在９—１３月龄...     

对侧外周神经移位到损伤手臂引起的体感皮层功能动态重组

单侧肢体的外周神经损伤通常导致对侧体感皮层的功能重组. 然而,接受了对侧颈 7 (C7) 外周神经移位手术治疗单侧手臂臂丛全撕脱的病人,在术后早期当其患手被触摸时,只在其健手产生感觉. 在术后晚期,病人才逐渐恢复其患手和健手的正常、独立的功能. 我们在模拟对侧颈 7 (C7) 外周神经移位手术病例的大鼠模型上,用记录体感诱发电位的方法研究了患手和健手的体感代表区. 患手的体感和运动功能由于 C7 神经的再生而逐渐恢复. 术后第 5 个月始, 13 只大鼠患手的体感代表区只出现在其同侧的皮层,同时患手和健手的代表区在该皮层内是高度重叠的 (除掉一个例外),虽然刺激它们产生的体感诱发电位的潜伏期和反应幅度有很大的不同. 结果表明,移位到患手的对侧外周神经能够导致同侧体感皮层动态的功能重组,提示身体另侧感觉输入的介入激发了大脑显著的可塑性.     

用独立分量分析和小波变换提取听觉诱发电位晚成分的强度变化

诱发电位的提取通常依靠相干平均方法,需要进行多次的重复刺激,实验时间较长.随着实验时间的增加,受试者生理因素及环境因素的变化,会影响诱发电位的正常形态(波形、强度和相位).利用独立分量分析和小波变换方法,通过时域信息和空域信息的综合应用,可成功提取到听觉诱发电位晚成分的强度在实验过程中的变化,对由于实验时间增加对晚成分的影响做出定量评价.结果表明,在10 min左右的实验过程中,听觉诱发电位晚成分的幅度会下降约40%.     

豚鼠耳蜗核内听觉诱发电位及其频域分析

用计算机叠加平均和脑干神经核团立体定位技术记录１０只豚鼠耳蜗核内听觉诱发电位（ＣＮ－ＡＥＰ）。对ＣＮ－ＡＥＰ时域波形中主波的潜伏期、振幅进行分析,并与豚鼠脑干听觉诱发电位（ＢＡＥＰ）时域波形进行比较,认为ＣＮ－ＡＥＰ是ＢＡＥＰⅡ波的主要成分。用自回归模型谱（ＡＲ谱）估计及数字滤波技术对ＣＮ－ＡＥＰ行频域分析,发现豚鼠ＣＮ－ＡＥＰ的频谱成分主要在１０００Ｈｚ以下,在ＡＲ谱图上有３个峰,Ｆ０、Ｆ１和Ｆ２,谱峰分别位于１８０、７１０、１２００Ｈｚ左右,略高于豚鼠ＢＡＥＰ的相应谱峰频率,其原因尚待进一步探讨。     

蜘蛛的视觉

很多蜘蛛有8只眼睛,在头部前端排成2列或者3列。根据排列位置,蜘蛛的眼睛可分为前中眼、前侧眼、后中眼和后侧眼。所有蜘蛛的眼睛都是单眼,表面是角膜,在角膜下皮层的内面是由特化的视觉细胞构成的视网膜。每一个视觉细胞有一个有核的细胞体,一端有视杆。根据核和视杆位置的不同,蜘蛛的单眼可以分为后视杆眼(前中眼)和前视杆眼(前、后侧眼和后中眼)。角膜后面是反光组织和色素细胞。     

幼猫单眼视剥夺和反缝过程中显示的双眼竞争机制

本研究以光栅为刺激所同时产生的图形视觉诱发电位和图形视网膜电图为指标,测定了单眼视剥夺和缝的新生幼猫个体在发育不同阶段的空间频率调谐曲线,并与同龃正常猫,成年正常猫进行了比较研究。结果显示,在０．１２－１．５ｃ／ｄ空间频率范围内,正常幼猫单独刺激其左眼和右眼所驱动的Ｐ－ＶＥＰ振幅相近,但都明显地比双眼驱动的为小。在单眼剥夺的幼猫,由剥夺眼所驱动的Ｐ－ＶＥＰ振幅大幅度下降,健康眼所驱动的Ｐ－ＶＥＰ则     

左旋多巴联合综合疗法治疗屈光不正性弱视患儿的临床效果

目的:探究左旋多巴联合综合疗法治疗屈光不正性弱视患儿的临床效果。方法:选取2013年4月至2016年3月在我院接受治疗的屈光不正性弱视青少年103例(180眼),随机分为对照组52例(90眼)和观察组51例(90眼)。对照组患儿给予常规的综合治疗,观察组在对照组之上给予左旋多巴治疗。治疗6个月后,观察比较两组患儿的治疗有效率、图形视觉诱发电位(P-VEP)、视觉对比敏感度和视功能等以及不良反应的发生情况。结果:观察组的视力治疗有效率为90.00%,显著高于对照组(68.89%),差异具有统计学意义(P0.05)。治疗6个月后,两组的振幅出现明显的升高,且观察组显著高于对照组(P0.05);两组的潜伏期发生明显降低,且观察组的显著低于对照组(P0.05)。观察组患儿的100%、25%、10%及5%空间频率视觉对比敏感度均显著低于对照组(P0.05)。观察组患儿的矫正辐辏范围、矫正分开范围显著高于对照组,矫正近立体锐度显著低于对照组(P0.05)。治疗期间,两组不良反应发生情况比较差异无统计学意义(P0.05)。结论:左旋多巴联合综合疗法可有效改善屈光不正患儿的视觉中枢神经元功能,明显提高视力水平及视觉敏感度。     

神经生长因子多药联合治疗缺血性视神经病变患者的临床疗效

目的:研究神经生长因子(NGF)多药联合治疗缺血性视神经病变(AION)患者的临床疗效。方法:选择2011年5月至2013年5月在我院接受治疗的AION患者100例(100只眼),根据数字表法随机分成观察组(50例,50只眼)及对照组(50例,50只眼)。对照组给予扩血管药和维生素神经营养性药物控制高血压或糖尿病等合并症,视情况给予糖皮质类激素治疗,观察组在此基础上另给予NGF药物治疗。对比两组疗效、对数视力、视野平均缺损值(MD)及视敏度通过图形视觉诱发电位(P-VEP100)P100波的潜伏期,观察两组不良反应。结果:观察组的总有效率为90.00%(45/50),显著高于对照组的74.00%(37/50),差异有统计学意义(P0.05)。两组在治疗后的对数视力、视野MD以及P-VEP100均有改善,但观察组的改善幅度显著大于对照组,差异有统计学意义(P0.05)。两组不良反应发生率差异无统计学意义(P0.05)。结论:NGF多药联合治疗AION患者疗效更佳,可促进患者视觉功能恢复,值得临床上推广使用。     

阿托品压抑疗法和遮盖疗法在治疗小儿弱视中的效果观察

目的:探讨遮盖疗法与阿托品压抑疗法治疗儿童弱视后视功能的变化差异。方法:90例单纯屈光参差弱视儿童随机分为压抑组和遮盖组各45例,两组弱视眼均佩带适矫眼镜,压抑组采用优势眼采用阿托品完全压抑法,遮盖组优势眼6h/日遮盖治疗,均连续治疗6个月,比较两组患儿视力变化情况。结果:治疗后压抑组的视力-0.044±0.137显著优于遮盖组视力-0.217±0.196(P0.05)。压抑组治疗后的P-VEP潜时、P-VEP振幅分别为105.3±4.9(ms)、14.8±3.6(uv)显著优于遮盖组(P0.05)。压抑组的立体视重建疗效分布显著的优于遮盖组(P0.05),压抑组的有效率80%显著的高于遮盖组的60%(P0.05)。压抑组的疗效分布显著的优于遮盖组(P0.05),压抑组的有效率84.44%显著的高于遮盖组的57.78%(P0.05)。结论:阿托品压抑疗法治疗弱视儿童较遮盖疗法具有更加显著的治疗效果。     

Two spatio-temporal filters in human vision

We have used the psychophysical methods described in the first paper of this series (Holliday and Ruddock, 1983) to determine selected spatial and temporal response characteristics of the ST1 and ST2 filters for subjects suffering visual defects. Data are given for 19 amblyopes, an albino and a hemianope, and comparison data are also given for a number of subjects with normal vision. The ST1 spatial responses for both the "normal" and "amblyopic" eyes of 12 convergent strabismic amblyopes are displaced to low spatial frequencies compared to the normal curve, which implies that there is a loss of fine spatial tuning. In all but one subject, the curve for the "amblyopic" eye peaks at a spatial frequency lower than that for the "normal" eye, thus the former deviates further from the normal pattern than the latter. The ST1 spatial responses of 6 refractive amblyopes are also displaced to the low frequency side of the normal curve, although on average the shift is smaller than in the case of the strabismic amblyopes. For each subject, the response curve of the "amblyopic" eye peaks at a lower spatial frequency than does that for the "normal" eye. ST1 spatial responses were measured for targets located up to 30 degrees off-axis along the horizontal meridian and sample data are given for one strabismic and one refractive amblyope and for two normal subjects. It is concluded from these data that the changes in the spatial responses associated with amblyopia do not simply reflect eccentric fixation of the target. The ST2 spatial response was measured for the "normal" and "amblyopic" eyes of 9 amblyopes (7 strabismic and 2 refractive). There is no significant difference between the average amblyopic response and that of normal subjects, and only in one case does the response for an "amblyopic" eye peak at a frequency lower than the peak frequency for normal vision. The ST2 temporal response for 9 amblyopes shows no systematic deviations from the normal response. For the albino, both the ST1 and ST2 spatial responses peak at around 0.3 cycles deg-1, and both curves are displaced considerably to the low spatial frequency side of the normal ST2 spatial response. The albino's ST2 temporal response is essentially normal. Measurements for the hemianope's "blind" hemifield under conditions appropriate to the isolation of the ST1 and ST2 spatial responses reveal no tuning curves. The ST2 temporal response for the "blind" hemifield, however, is of large amplitude, with a peak at 2 Hz, well below the normal frequency response peak. It is argued that the loss of fine spatial tuning which occurs in the ST1, but not the ST2, spatial responses of the amblyopes is consistent with the sequential organisation of these two filter classes proposed by Holliday and Ruddock (1983). Further, for the only two subjects whose ST2 spatial response curves are displaced to abnormally low frequencies (the albino and a strabismic amblyope) the ST1 spatial response is shifted to low spatial frequencies compared to the normal ST2 curve...     

Clinical evaluation of VEPs to interleaved checkerboard reversal stimulation of central,hemi- and peripheral fields

The VEPs of 195 patients referred for supportive evidence of multiple sclerosis or optic neuritis were studied by a new method of interleaved checkerboard reversal stimulation of different areas of the visual field. In the first group of 95 patients checks of 40′ subtense reversed in the whole field (28° × 20°), alternately in the left and right hemifields and alternately in the central (5° radius) and peripheral fields. In the second group of 100 patients checks reversed in the whole field and in interleaved mode in 3 visual field areas, comprising the central (4° radius) and left and right hemisurround fields.In the first group abnormal responses were recorded from 52 eyes and there was partial disagreement among the stimulus conditions in 10 of the 52. Abnormalities were seen uniquely to central field stimulation in 3 eyes but never to whole field stimulation alone. In the second group abnormal responses were recorded in 58 eyes, again never uniquely to whole field stimulation, while abnormalities confined to one or two areas of the visual field were seen in 24, providing evidence of peripheral field involvement alone in 8 eyes.In the first group, waveforms created from the sum of the left and right hemifield and central and peripheral field responses showed quite close conformity to the whole field VEP, although amplitudes were significantly lower and latencies significantly shorter. In 7 eyes responses would have been differently classified (normal or abnormal) using the sum as compared with the whole fields. The sum of the 3 interleaved stimuli was less reliable, its morphology often not closely approximating whole field responses.It is suggested that interleaved stimulation of two or more areas of the visual field is a sensitive and reliable method which reduces the time necessary to perform the test and helps control the patients' concentration, fixation and alertness. Whole field stimulation is probably necessary only in patients with severely degraded responses.     

Processing Deficits of Motion of Contrast-Modulated Gratings in Anisometropic Amblyopia

Several studies have indicated substantial processing deficits for static second-order stimuli in amblyopia. However, less is known about the perception of second-order moving gratings. To investigate this issue, we measured the contrast sensitivity for second-order (contrast-modulated) moving gratings in seven anisometropic amblyopes and ten normal controls. The measurements were performed with non-equated carriers and a series of equated carriers. For comparison, the sensitivity for first-order motion and static second-order stimuli was also measured. Most of the amblyopic eyes (AEs) showed reduced sensitivity for second-order moving gratings relative to their non-amblyopic eyes (NAEs) and the dominant eyes (CEs) of normal control subjects, even when the detectability of the noise carriers was carefully controlled, suggesting substantial processing deficits of motion of contrast-modulated gratings in anisometropic amblyopia. In contrast, the non-amblyopic eyes of the anisometropic amblyopes were relatively spared. As a group, NAEs showed statistically comparable performance to CEs. We also found that contrast sensitivity for static second-order stimuli was strongly impaired in AEs and part of the NAEs of anisometropic amblyopes, consistent with previous studies. In addition, some amblyopes showed impaired performance in perception of static second-order stimuli but not in that of second-order moving gratings. These results may suggest a dissociation between the processing of static and moving second-order gratings in anisometropic amblyopia.     

Spectral analysis of dual jerk waveforms in congenital nystagmus

Congenital nystagmus (CN) is a disorder of the ocular motility characterized by oscillatory eye movements preventing the correct fixation of a target. Many typical waveforms of eye position recordings have been recognized and classified in the literature: in jerk CN a slow phase eye movement is followed by a fast phase, giving rise to a typical saw-tooth waveform, while in pendular CN the eyes exhibit a periodic motion, giving rise to an approximately sinusoidal waveform. Dual jerk waveforms seemed to show small, rapid oscillations superimposed on a jerk-like waveform, thus being originary classified as a mixture of jerk and pendular CN. On the contrary, a theoretical model of CN has appeared recently, which suggests a possible interpretation of the small amplitude oscillations in dual jerk waveforms as consecutive pieces of growing and decaying exponentials.By spectral analysis of dual jerk waveforms in a number of patients with CN, we show that the oscillations are truly sinusoidal in nature, thus suggesting the possibility of a different explanation of dual jerk waveforms in CN.Preliminary results of this work were presented at XIV ICMP —International Congress of Medical Physics, Espoo, Finland, 11–16 August 1985     

Interactions between bacteria-feeding nematodes and bacteria in the rape rhizosphere: effects on root exudation and distribution of bacteria

Abstract Effects of rhizosphere bacteria (RB), and rhizosphere bacteria with bacteria-feeding nematodes (RBN), on the composition of root exudate were examined after 2 weeks in gnotobiotic culture systems with rape seedlings ( Brassica napus (L.)). The amounts of low molecular weight carbohydrates and of some free amino acids, per unit root dry weight, in the exudates were lower in the RB and RBN treatments than in the axenic control (R treatment). The growth of nematodes implied a production of bacterial cells in the RBN treatment 2.6 times that in the RB treatment. The bacterial growth in the RB treatment and the bacterial growth in combination with grazing by nematodes in the RBN treatment implied 24 and 63 times as much exudation of organic carbon, respectively, as in the R treatment.
Most bacteria were attached to sand particles. The nematodes being suspension-feeders, decreased the proportion of free bacteria from 6% in the RB treatment to 2% in the RBN treatment. The numbers of attached bacteria in the RBN treratment were positively correlated with the numbers of nematodes, indicating stimulation of bacterial growth by the grazing.