扫描翻转图像视觉诱发电位视力与对数视力表视力的比较

目的 对扫描图像视觉诱发电位视力(SPVER视力)与对数视力表视力进行比较。方法比较50例受试者的视力表和SPVER视力。在SPVER视力的测定中用了8个不同空间频率的光栅条纹连续扫描,所得数据经离散傅立叶分析后,获得振幅一空间频率曲线,并由外推法估计其视力。结果SPVER视力与视力表视力的总体相关系数r=0．699,在视力表视力大于0．5时,SPVER视力有低估现象,而在视力表视力小于0．5时SPVER视力有高估现象。结论SPVER视力与视力表视力有良好的相关性。由于视力表视力和SPVER视力所用于评估视力的指标不同,使两者结果不完全相同。     

Visual behaviours of neurologically impaired children with cerebral visual impairment: an ethological study

BACKGROUND/AIMS—Visual functions of neurologically impaired children with permanent cerebral visual impairment (CVI) can be difficult to determine. This study investigated the behavioural profile of CVI children by means of ethological observations in order to gain a better understanding of their visual functions.
METHODS—Video registrations of nine subjects who were unable to undergo more orthodox methods of visual function testing were observed and analysed by an ethologist.
RESULTS—A series of behaviours (direct signs) and supportive or confirming behavioural elements (indirect signs) indicating some visual perception in the children were found.
CONCLUSION—Detailed ethological observations of visual behaviour were shown to be useful for analysing visual functions of children with permanent CVI.

Keywords: cerebral visual impairment; visual function; visual behaviour; ethological analysis     

阅读的视觉心理物理学研究方法及影响因素的研究进展

阅读是最重要的视觉工作,许多眼部疾病的首要症状就是阅读困难。临床上通常是通过视力检查来了解阅读情况的。但阅读是一个综合行为,它要求的不仅仅是好的视力,而是受到多种因素的影响。本综述对阅读研究中常用的视觉呈现方式、阔读表现的评估和影响因素等作一简要介绍。     

视力及视野损害与交通事故

视力和视野是安全驾驶的必要条件.各国获取驾驶执照对视力和视野要求不同,但大多数国家视力标准为双眼视力不能低于0.5,水平视野为120°.在过去20年里,大量的研究关注视觉在驾驶中所起的作用,视觉损害对发生交通事故的影响.较早期的研究证明,视觉损害可使事故增加,视觉与事故有明显的相关性.但近期大量的研究认为较好视觉与较差视觉相比事故发生率无差别,因而认为视觉与交通事故无明显相关.上述两种研究结果互相矛盾,可能是由于安全驾驶是需要人、车及环境因素成功地整合及参与才能完成.因此,建议今后关于安全驾驶的研究除视觉外,尚需考虑其他因素.     

光环境对不同视力者视觉绩效的影响

目的:研究不同模拟光环境下不同视力者视觉绩效的变化,为修订飞行人员视力标准提供试验依据。方法:随机对照研究。招募24名志愿者,根据右眼/左眼视力分为1.0/1.0、0.8/0.8、0.6/0.6和0.4/0.4(小数视力)4组,每组6人,分别在模拟日光、曙暮光和云上光环境下检测双眼静态远视力、动态视力、色觉和深径觉误差及视觉搜索时间,比较不同光环境对不同视力者视觉绩效指标影响的变化。结果:不同光环境下双眼静态远视力、动态视力、色觉误差、深径觉误差和视觉搜索时间存在主效应差异(均P<0.01)。日光下双眼静态远视力、色觉辨别、深径觉和视觉搜索能力均高于曙暮光和云上光。在0.4/0.4视力组,曙暮光、云上光环境下动态视力显著低于日光环境(P<0.01)。不同视力者双眼静态远视力、动态视力、深径觉误差和视觉搜索时间存在主效应差异(均P<0.05)。与1.0/1.0视力组比较,0.6/0.6、0.4/0.4视力组动态视力、深径觉和视觉搜索能力显著下降(均P<0.05)。结论:不同光环境对视力低于正常者视觉绩效存在明显影响,对飞行安全构成潜在的威胁。     

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.     

Visual function and visual perception in cerebral palsied children

PURPOSE: To investigate visual function and perception in cerebral palsied (CP) children. METHODS: A total of 105 congenitally CP children (aged 6-15 years), without severe mental retardation, were classified into three groups: those with spastic quadriplegia, spastic diplegia and spastic hemiplegia. Data collected included patient history, IQ, refraction, far and near visual acuity, position of the eyes and eye movements, visual fields, colour perception, stereoacuity, slit lamp and fundoscopic examinations, and evaluation of visual perception. The results were compared with a control group from the general paediatric population. RESULTS: The IQ of the CP children ranged between 70 and 100. A total of 59% of them had best corrected distance visual acuity <6/6, with 25.5% <6/9. Near visual acuity was also reduced (70.1% scored <6/6 and 38.4% scored <6/9). Incidence of refractive errors was higher than in the control group (hypermetropia in 43.8% of the eyes, myopia 16.19% and astigmatism 40.9%) as was the incidence of strabismus (26.7% esotropic and 27.6% exotropic). In visual field testing, 80.95% of CP children were normal. A total of 94.28% had normal colour perception and 89.52% were free of ocular pathology. Stereopsis was abnormal or absent in 85.71% of the cases. Visual perception was markedly reduced: in 57.14% of the cases it was less than or equal to that of 6-year-old children; in 26.66% equal to that of 6- to 7.5-year-old children, and in 16.2% of the cases greater than or equal to that of 7.5-year-old children. CONCLUSIONS: In the absence of severe mental retardation, CP children have deficient visual skills. It is suggested that the poor visual skills of CP children are a separate, identifiable factor compounding the adverse effects of mental retardation.     

两种干涉条纹视力计对白内障患者术后视力预测的对照研究

目的通过国产干涉条纹视力计与Heine干涉条纹视力计在预测白内障患者术后视力中的应用对比,探讨国产干涉条纹视力计预测白内障患者术后视力的准确性、实用性、可行性。方法将71例(92眼)白内障患者平均分成2组,术后的视功能情况分别用国产干涉条纹视力计与Heine干涉条纹视力计2种方法进行预测,结果与患眼术后最佳矫正视力进行相关性分析对比。结果国产干涉条纹视力计预测的准确率为81.0%(预测视力与术后视力相差2行以内者认为准确),平均预测视力(4.695)与平均术后最佳矫正视力(4.771)比相差不到1行。Heine干涉条纹视力计预测的准确率为43·9%,平均预测视力(4.481)与平均术后最佳矫正视力(4.771)比相差约3行。结论比起Heine干涉条纹视力计,国产干涉条纹视力计检查更能合理的反映视觉功能,对白内障术后视力具有较好的预测性。     

视觉噪声双视力表在弱视检查中的临床应用

目的 探讨视觉噪声双视力表在弱视视觉敏感度检测中的临床应用价值.方法 弱视门诊随机选择100例弱视患者作为弱视组,同时随机抽取100例屈光不正患者作为对照组,使用视觉噪声双视力表分别检测2组患者在有、无视觉噪声条件下视力.然后分别将2组中有、无视觉噪声条件下的视力求差后进行对比研究,以明确视觉噪声双视力表在弱视检查中的应用价值.结果 2组中所有患者在有视觉噪声下的视力均低于无视觉噪声条件下的视力,其中弱视组有、无视觉噪声条件下测得的视力相差(1.62±1.11)行,对照组的视力相差(0.97±0.61)行,2组之间差异有统计学意义(t=5.355,P<0.05).结论 视觉噪声双视力表能够提示弱视者的视觉噪声加工缺陷,借此将弱视者和其他视觉异常者区分开来;可作为常规枧力检查的有益补充,用于弱视的临床检测和诊断.     

噪声视力表在儿童视力检查中的可重复性分析

目的探讨噪声视力表对儿童视力检查的可重复性及其相关影响因素。方法在门诊首诊患儿中,随机选择无理解障碍及除屈光不正外无其他器质性眼病儿童200例,使用噪声视力表进行噪声视力重复检查。采用配对t检验进行统计学分析。结果两次视力测量之间差异的均数为O.03行,（P=0.515）;两次视力测量结果按性别分组无明显差异（P=1.0,P=0.262）;按年龄分组亦无明显差异（P=0.159,P=0.786）;按屈光不正分组,其中近视组两次视力测量结果有明显差异（P=0.010）。近视儿童视力检查一致性较差,而正视及远视儿童的视力检查一致性较好（P=0.133,P=0.083）。结论结果提示噪声视力表适合儿童视力检查,建议推广使用。     

The technique, validity and clinical use of the sweep VEP

Vision scientists have concentrated on studying two visual functions when it comes to assessing the sensory visual development in human: visual acuity and contrast sensitivity. The methods used to measure these visual functions can be either behavioral or electrophysiological. A relatively new technique for measuring the visual acuity and contrast sensitivity electrophysiologically is the sweep visual evoked potential (sVEP). This paper is a review of the literature on the sVEP technique: stimulus parameters, threshold determination, validity and reliability of sVEP are discussed. Different studies using the sVEP to study the development of visual acuity, contrast sensitivity, and vernier acuity are presented. Studies have demonstrated that the sVEP is a potentially important tool for assessing visual acuity and contrast sensitivity in non-verbal individuals with disorders affecting their visual system.     

Properties of visual evoked potentials to onset of movement on a television screen

In 80 subjects the dependence of movement-onset visual evoked potentials on some measures of stimulation was examined, and these responses were compared with pattern-reversal visual evoked potentials to verify the effectiveness of pattern movement application for visual evoked potential acquisition. Horizontally moving vertical gratings were generated on a television screen. The typical movement-onset reactions were characterized by one marked negative peak only, with a peak time between 140 and 200ms. In all subjects the sufficient stimulus duration for acquisition of movement-onset-related visual evoked potentials was 100ms; in some cases it was only 20ms. Higher velocity (5.6°/s) produced higher amplitudes of movement-onset visual evoked potentials than did the lower velocity (2.8°/s). In 80% of subjects, the more distinct reactions were found in the leads from lateral occipital areas (in 60% from the right hemisphere), with no correlation to handedness of subjects. Unlike pattern-reversal visual evoked potentials, the movement-onset responses tended to be larger to extramacular stimulation (annular target of 5°–9°) than to macular stimulation (circular target of 5° diameter).Abbreviation PREP pattern-reversal visual evoked potentials     

慢性青光眼患者不同程度视野缺损情况分析

目的:研究单眼视野已严重缺损的慢性青光眼患者对侧眼视野缺损情况,并分析其视野缺损的相关危险因素。方法:对47例单眼视野已严重缺损(视野缺损计分≥12分)的慢性青光眼患者[原发性慢性闭角型青光眼(primary chronic angle-closed glaucoma,PACG)23例和原发性开角型青光眼(primary openangle glaucoma,POAG)24例]的对侧眼视野进行视野缺损计分,分析对侧眼视力、最高眼压和平均眼压、年龄、屈光度、诊断、病程、性别及抗青光眼手术与否与对侧眼视野缺损计分的关系。应用Spearman相关分析分析上述因素与对侧眼视野缺损计分的相关性。结果:23例PACG患者中,对侧眼视野缺损情况为:无视野缺损者(计分为0分)4例,轻度视野缺损者(计分为1~5分)5例,中度视野缺损者(计分为6~11分)7例,严重视野缺损或终末期视野缺损者(计分为12~20分)7例。24例POAG患者中,对侧眼视野缺损情况为:轻度视野缺损者(计分为1~5分)4例,中度视野缺损者(计分为6~11分)9例,严重视野缺损或终末期视野缺损者(计分为12~20分)11例。PACG患者病程大于或等于10年...     

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Abstract

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.     

A Review of Strategies for Screening of the Visual Fields

: Some strategies for rapid investigation of the visual fields are reviewed. Those aspects considered are the testing of central and peripheral fields, the pattern and density of sampling the visual field with static stimuli and the most suitable stimulus intensity at which to begin the screening of each subject. Some of the design features of 10 visual field screeners and 3 automated perimeters are tabulated to indicate the importance of control of perimetric variables and how strategies for screening have developed from earlier to later designs.     

视雪综合征的研究进展

本文系统介绍了视雪综合征(visual snow syndrome,VSS),这是一种无明确原因,表现为无数闪烁的小点持续存在于整个视野中,并可能伴有后像、内视、畏光、夜盲的视觉现象。目前已经有文献对该疾病进行了临床及病理生理学研究,最新的文献资料中,更倾向于视雪综合征是一种视觉处理功能障碍,需与偏头痛等疾病相鉴别。在治疗方面,目前多是试验性研究,有病例报道显示抗癫痫、抗抑郁药、乙酰唑胺等和有色滤光片对缓解患者症状可能有积极作用。     

视皮层背侧、腹侧流视觉通路的研究进展

视皮层是大脑视觉信息的处理整合中心,灵长类动物的视皮层存在背侧和腹侧流2条相对独立而又相互联系的平行视觉信息通路。笔者总结了视皮层背侧通路（即where+how通路）、腹侧通路（即what通路）的发现、定位、功能以及二者的联系,并从视觉通路临床应用角度系统梳理了视觉皮层背侧、腹侧平行通路的研究进展。目前2条通路结构和功能相关性研究资料较少,对视皮层视觉通路的视觉信息分拣处理、相互作用及通路信息传递过程编码和神经整合处理机制尚缺乏深入研究。此外,关于2条通路的临床研究缺乏系统性和完整性,且研究结果分歧较大,今后需改进研究方法,加强深入研究视觉疾病视通路损害的结构和功能。本文通过对视皮层背侧通路、腹侧通路做—综述,以期为视觉信息的传递、加工和相关临床眼病防治研究提供理论基础。     

临床视觉电生理学检查技术在动物实验研究中的应用

There are different techniques or methods to record visual or retinal function changes in laboratory animals. Clinical visual electrophysiological testing is a non-invasive diagnostic method that can record animal visual function in vivo. It can be used as a tool to investigate the visual physiological phenomena. It is also taken as an objective indicator to monitor visual function changes, such as the effect of various factors （whether physical, chemical or biological） on visual functions, evaluation of therapeutic efficiency, diagnosis for disease or drug development. There are many factors that might affect visual electrophysiological testing results so experimental control studies are necessary. The investigation of the new methods, indicators and analysis methods are the focus of research in this field. Establishing a standard experimental methodology is crucial for the technique to become widespread with good quality control.     

Perceptual visual dysfunction in children - An Indian perspective

Perceptual visual dysfunction (PVD) comprises a group of vision disorders resulting from dysfunction of the posterior parietal and/or temporal lobes. Often, affected children have normal/near normal visual acuities and/or visual fields, but have difficulties in activities of daily living involving the use of vision. PVDs are known to be common among children with risk factors such as a history of prematurity and/or neurodevelopmental disorders. The inferior temporal lobes and ventral stream transform visual signals into perception, while the posterior parietal lobes and dorsal stream transform visual signals to non-consciously map the scene to guide action and facilitate attention. Dysfunction of these can lead to specific visual impairments that need to be identified during history taking, triggering ascertainment of further details by a structured inventory approach. Clinical tests to elicit dorsal and ventral stream visual dysfunctions have good specificity but low sensitivity. Neuropsychologists are rarely available in the developing world to perform detailed assessments, but there are a few tests that can be used by eye care professionals with some training. Optical coherence tomography (OCT) showing thinning of the ganglion cell layer and retinal nerve fiber layer is being explored as a potential tool for rapid assessment in the clinic. The behavioral outcomes of PVD can mimic psychological conditions including autism spectrum disorder, attention deficit hyperactivity disorder, specific learning disability, and intellectual impairment, and one needs to be aware of overlap among these differential diagnoses. A practical functional approach providing working solutions for each child''s set of difficulties in day-to-day activities is needed.     

视觉电生理检查判断白内障预后的临床分析

目的:探讨分析超声乳化手术前作视觉电生理检查对白内障预后的临床价值。方法:选取2009-01/2010-10在我院行白内障超声乳化手术治疗的白内障患者,针对直接和间接眼底镜下眼底窥不清253例,术前作视觉电生理检查了解视网膜和视神经情况以判断预后。结果:该253例患者中有47例经视觉电生理检查提示预后较差,其中接受白内障手术37例,有35例术后视功能恢复也相应较差(术后视力提高≤2行),2例术后视功能恢复情况相对较好(术后视力提高>2行),另10例放弃手术;206例经视觉电生理检查提示预后较好,其中201例接受白内障手术,有199例术后视功能恢复也相应较好(术后视力提高>2行),2例术后视功能恢复情况相对较差(术后视力提高≤2行),5例因有全身其他疾病不能手术。结论:白内障术前作视觉电生理检查了解视网膜及视神经情况,对于判断手术预后有良好的可预测性。