弱视儿童的视知觉研究进展

弱视是较为常见的眼病,是视觉发育敏感期异常视觉经验所导致的以空间视力损害为特征的一组视力不良综合征。本文通过整理以往研究,对弱视儿童视知觉的研究作了综述,主要包括空间特征对弱视儿童形状知觉的影响、空间方位对弱视儿童立体视觉的影响、空间目标对弱视儿童视知觉的影响、不同的目标运动特征对弱视儿童视觉运动觉的影响,以及弱视儿童视知觉相关的脑机制研究。[眼科新进展,2012,32(9):893-898]     

弱视与视觉系统可塑性

弱视是一种发育性眼科疾病,其发病与视觉系统发育关键期内的异常视觉经验密切相关。传统的弱视治疗方法对已超过视觉发育关键期的大龄儿童和成年弱视患者几乎没有效果。知觉学习指经过感知觉训练引起的知觉任务成绩的特异性提高,其生理学基础是神经系统的可塑性。近年来的研究表明,视知觉学习可以显著提高正常人以及诸多高等动物的视知觉功能,并且可以显著改善弱视等视觉系统功能受损患者的视觉功能。动物电生理学研究表明视知觉学习导致了视皮层内神经元调谐特性的改善。这些研究提示我们,即使超过了视觉系统发育的关键期,视觉神经系统仍然存在一定的可塑性。     

知觉学习在弱视治疗中的应用

近年来,随着视觉神经科学与心理物理学和认知神经科学不断交叉融合发展,知觉学习逐渐被认识到具有提高多重视觉功能的能力。由此,知觉学习作为一种新的潜在的治疗弱视的方式被提出,同时出现了多种基于知觉学习理论的弱视的治疗方法。本文将在简要阐述知觉学习及其机制的基础上,介绍基于知觉学习的新的弱视治疗理念和方法,并探讨其临床应用的进展。     

视知觉学习治疗成人弱视

弱视是一种由早期异常视觉经历引起的视觉系统发育性疾病。过去多数学者认为发育成熟后,弱视治疗基本无望。对青少年及成人弱视的治疗,目前国内报道尚少。而多年来临床上成人弱视治疗主要包括遮盖加精细作业、CAM疗法、后象法、红色滤光片法、压抑疗法     

视知觉学习与注意力的关系

随着人们对弱视本质以及大脑神经可塑性研究的深入,视知觉学习的概念被逐渐引入到弱视研究领域。由于视知觉学习过程中可能涉及到注意力机制,而且先前的研究显示二者之间存在相互作用。为进一步认识视知觉学习的本质,从认知神经科学和心理物理学的角度对视知觉学习与注意力关系进行综述,如弱视的视觉缺陷表现形式与发病部位、视知觉学习的特点和机制、注意力在视知觉学习中的作用及视知觉学习对注意力的影响。     

知觉学习训练在弱视治疗中的应用

知觉学习是个体从外界环境中提取信息提高能力的过程,是练习与生理成熟相互作用的结果.许多基础研究发现知觉学习与成年人视皮层可塑性具有明确的关系,而临床试验也证实,知觉学习能够有效地治疗青少年及成年人弱视,而且具有主动、实效的特点.作为传统弱视治疗方法的补充和替代,知觉学习系统的开发,为弱视治疗开辟了新的领域.本文就知觉学习的机制、方法及其在弱视中的应用作一综述.     

知觉学习训练在弱视治疗中的应用

知觉学习是个体从外界环境中提取信息提高能力的过程,是练习与生理成熟相互作用的结果.许多基础研究发现知觉学习与成年人视皮层可塑性具有明确的关系,而临床试验也证实,知觉学习能够有效地治疗青少年及成年人弱视,而且具有主动、实效的特点.作为传统弱视治疗方法的补充和替代,知觉学习系统的开发,为弱视治疗开辟了新的领域.本文就知觉学习的机制、方法及其在弱视中的应用作一综述.     

知觉学习训练在弱视治疗中的应用

知觉学习是个体从外界环境中提取信息提高能力的过程,是练习与生理成熟相互作用的结果.许多基础研究发现知觉学习与成年人视皮层可塑性具有明确的关系,而临床试验也证实,知觉学习能够有效地治疗青少年及成年人弱视,而且具有主动、实效的特点.作为传统弱视治疗方法的补充和替代,知觉学习系统的开发,为弱视治疗开辟了新的领域.本文就知觉学习的机制、方法及其在弱视中的应用作一综述.     

知觉学习训练在弱视治疗中的应用

知觉学习是个体从外界环境中提取信息提高能力的过程,是练习与生理成熟相互作用的结果.许多基础研究发现知觉学习与成年人视皮层可塑性具有明确的关系,而临床试验也证实,知觉学习能够有效地治疗青少年及成年人弱视,而且具有主动、实效的特点.作为传统弱视治疗方法的补充和替代,知觉学习系统的开发,为弱视治疗开辟了新的领域.本文就知觉学习的机制、方法及其在弱视中的应用作一综述.     

知觉学习训练在弱视治疗中的应用

知觉学习是个体从外界环境中提取信息提高能力的过程,是练习与生理成熟相互作用的结果.许多基础研究发现知觉学习与成年人视皮层可塑性具有明确的关系,而临床试验也证实,知觉学习能够有效地治疗青少年及成年人弱视,而且具有主动、实效的特点.作为传统弱视治疗方法的补充和替代,知觉学习系统的开发,为弱视治疗开辟了新的领域.本文就知觉学习的机制、方法及其在弱视中的应用作一综述.     

Amblyopia: diagnostic and therapeutic options

PURPOSE: To provide an overview of the current state of knowledge of amblyopia and highlight recent advances in diagnosis and treatment. DESIGN: Review of literature and perspective. METHODS: MEDLINE search for amblyopia, with a review of all recent literature adding authors' personal perspectives on the findings. RESULTS: Increased awareness of amblyopia and better screening techniques are required to identify children who are at risk for amblyopia at a younger age. Randomized, controlled trials have established atropine penalization as a viable alternative to occlusion therapy, have suggested that less treatment may be better tolerated and as effective as more traditionally used dosages, and have found no compelling evidence that treatment is beneficial clinically for older (over age 10) children with amblyopia. CONCLUSION: Early detection and treatment of amblyopia can improve the chances for a successful visual outcome. Considering that the conditions that place a patient at risk for amblyopia can be identified, that amblyopia responds to treatment, and that well-tolerated treatments for the condition are now recognized, it is not unreasonable to imagine that, in the near future, severe amblyopia could be eliminated as a public health problem.     

弱视复发因素探讨

了解弱视治愈远期疗效的影响因素。方法　对259例(448眼)基本治愈的弱视患者进行了3年以上的随访观察。经散瞳验光后证实视力下降至≤0.9时为弱视复发眼。结果　本组弱视复发率为29.24%。屈光参差性弱视和斜视性弱视的复发率明显高于屈光不正性弱视的复发率;弱视程度越重,复发率就越高;中心注视性弱视复发率低于旁中心注视性弱视复发率。结论　弱视复发率因弱视类型和弱视程度不同而异。随停止治疗的时间逐渐延长,弱视复发病例逐渐减少。对于易复发的弱视类型应进行重点监测。     

Studies on ‘meridional amblyopia’ by VECP after pattern reversal stimulation

With the aim of investigating the so-called ‘meridional amblyopia’, the authors compared the meridional sensitivity of astigmatic subjects between the two principal meridians (meridional ratio), using the Visually Evoked Cortical Potentials (VECP) after pattern reversal stimulation. The following results were obtained: Unilateral cases with amblyopia showed a higher meridional ratio than bilateral cases with amblyopia. In unilateral as well as in bilateral cases with amblyopia, the meridional ratio decreased along with optical correction and occlusion therapy, and finally it became within a normal range. It is suggested that meridional amblyopia should be regarded either as anisometropic amblyopia or ametropic amblyopia.     

要特别重视儿童弱视诊断中的年龄因素

各国学者对弱视的视力界定数值不一,国内现行诊断标准（低于0．9）明显高于国外。我们调查发现3～6岁健康儿童的5％视力参考值下限低于0．70。矫正视力低于0．9作为弱视诊断标准对于低龄儿童过高,将一些视力发育中的低龄儿童诊断为弱视,导致数以百万计的儿童误诊误治。不能正确考虑幼儿年龄因素影响,可造成转诊率和假阳性率升高,增加筛查费用和家长经济负担。因此建议在诊断弱视时,应对不同年龄组儿童采用不同的视力标准。（中华眼科杂志,2007,43：961—964）     

强化后像综合疗法治疗儿童弱视488例观察

目的 探讨强化后像综合疗法治疗儿童弱视的疗效.方法 对确诊为弱视的488例598只眼门诊儿童患者,按不同原因引起的弱视,分别给予以强化后像为主的综合治疗,对弱视的年龄、弱视的类型、弱视的程度、弱视的性质以及弱视治疗的时间与疗效的关系分别进行分析.结果 通过强化后 像为主的综合治疗,随访1-2年,488例598只眼:基本治愈378只眼,有效170只眼,无效50只眼.弱视治疗的总有效率91.64%,其中治愈率63.21%,进步28.43,无效8.36%,3～6岁年龄组、屈光不正性弱视、轻度弱视、中心性注视治疗治愈率最高,治疗时间坚持越长治疗效果越好.结论 弱视的疗效与患儿的年龄、弱视的类型、弱视的性质、弱视的程度及弱视的治疗时间密切相关,强化后像综合疗法治疗儿童弱视疗效显著,值得临床推广.     

强化后像综合疗法治疗儿童弱视488例观察

目的 探讨强化后像综合疗法治疗儿童弱视的疗效.方法 对确诊为弱视的488例598只眼门诊儿童患者,按不同原因引起的弱视,分别给予以强化后像为主的综合治疗,对弱视的年龄、弱视的类型、弱视的程度、弱视的性质以及弱视治疗的时间与疗效的关系分别进行分析.结果 通过强化后 像为主的综合治疗,随访1-2年,488例598只眼:基本治愈378只眼,有效170只眼,无效50只眼.弱视治疗的总有效率91.64%,其中治愈率63.21%,进步28.43,无效8.36%,3～6岁年龄组、屈光不正性弱视、轻度弱视、中心性注视治疗治愈率最高,治疗时间坚持越长治疗效果越好.结论 弱视的疗效与患儿的年龄、弱视的类型、弱视的性质、弱视的程度及弱视的治疗时间密切相关,强化后像综合疗法治疗儿童弱视疗效显著,值得临床推广.     

强化后像综合疗法治疗儿童弱视488例观察

目的 探讨强化后像综合疗法治疗儿童弱视的疗效.方法 对确诊为弱视的488例598只眼门诊儿童患者,按不同原因引起的弱视,分别给予以强化后像为主的综合治疗,对弱视的年龄、弱视的类型、弱视的程度、弱视的性质以及弱视治疗的时间与疗效的关系分别进行分析.结果 通过强化后 像为主的综合治疗,随访1-2年,488例598只眼:基本治愈378只眼,有效170只眼,无效50只眼.弱视治疗的总有效率91.64%,其中治愈率63.21%,进步28.43,无效8.36%,3～6岁年龄组、屈光不正性弱视、轻度弱视、中心性注视治疗治愈率最高,治疗时间坚持越长治疗效果越好.结论 弱视的疗效与患儿的年龄、弱视的类型、弱视的性质、弱视的程度及弱视的治疗时间密切相关,强化后像综合疗法治疗儿童弱视疗效显著,值得临床推广.     

Amblyopia: prevalence,natural history,functional effects and treatment

Amblyopia, defined as poor vision due to abnormal visual experience early in life, affects approximately three per cent of the population and carries a projected lifetime risk of visual loss of at least 1.2 per cent. The presence of amblyopia or its risk factors, mainly strabismus or refractive error, have been primary conditions targeted in childhood vision screenings. Continued support for such screenings requires evidence‐based understanding of the prevalence and natural history of amblyopia and its predisposing conditions, and proof that treatment is effective in the long term with minimal negative impact on the patient and family. This review summarises recent research relevant to the clinical understanding of amblyopia, including prevalence data, risk factors, the functional impact of amblyopia and optimum treatment regimes and their justification from a vision and life skills perspective. Collectively, these studies indicate that treatment for amblyopia is effective in reducing the overall prevalence and severity of visual loss from amblyopia. Correction of refractive error alone has been shown to significantly reduce amblyopia and less frequent occlusion can be just as effective as more extensive occlusion. Occlusion or penalisation in amblyopia treatment can create negative changes in behaviour in children and impact on family life, and these factors should be considered in prescribing treatment, particularly because of their influence on compliance. Ongoing treatment trials are being undertaken to determine both the maximum age at which treatment of amblyopia can still be effective and the importance of near activities during occlusion. This review highlights the expansion of current knowledge regarding amblyopia and its treatment to help clinicians provide the best level of care for their amblyopic patients that current knowledge allows.     

目前我国弱视临床防治中亟待解决的问题

多年来,矫正视力低于0.9(≤0.8)一直是我国眼科临床诊断弱视的视力标准,没有不同年龄儿童正常视力的参考值,出现了弱视诊断扩大化的现象.目前在弱视诊断中存在两个"单一"弊病:忽视形成弱视的诸多相关因素,只考虑视力单一因素;忽视视觉发育规律,不分年龄大小只用0.9一个视力标准诊断弱视.因此.对学龄前不同年龄组儿童应采用不同的视力标准,同时强调诊断弱视须具有弱视形成的相关因素.     

Amblyopia therapy: an update

We review the findings of trials of mainstay amblyopia treatment conducted within the last 5 years. These have confirmed that an initial period of full-time refractive correction is beneficial in all types of amblyopia. Adopting this practice may allow up to 30% of children to avoid any further treatment. Studies that have investigated the role of atropine occlusion as a first-line treatment for amblyopia have shown "weekend atropine" to be as effective as patching for children with both moderate and severe amblyopia. Where patching is prescribed, 2-4 hours/day of occlusion appears sufficient to provide an optimum outcome for the majority of children, although those over 6 years tend to require a larger dose to achieve best outcome, their amblyopia being more resistant to treatment. Educational interventions such as cartoons and written and video explanations of treatment aimed at improving compliance appear to raise it to a therapeutic level in those who may otherwise have poor compliance or drop out from treatment. Formal, evidence-based practice guidelines for the management of amblyopia have emerged although their adoption by practitioners, at least in the United Kingdom, has been questioned.