Neural mechanisms of recovery following early visual deprivation

Natural patterned early visual input is essential for the normal development of the central visual pathways and the visual capacities they sustain. Without visual input, the functional development of the visual system stalls not far from the state at birth, and if input is distorted or biased the visual system develops in an abnormal fashion resulting in specific visual deficits. Monocular deprivation, an extreme form of biased exposure, results in large anatomical and physiological changes in terms of territory innervated by the two eyes in primary visual cortex (V1) and to a loss of vision in the deprived eye reminiscent of that in human deprivation amblyopia. We review work that points to a special role for binocular visual input in the development of V1 and vision. Our unique approach has been to provide animals with mixed visual input each day, which consists of episodes of normal and biased (monocular) exposures. Short periods of concordant binocular input, if continuous, can offset much longer episodes of monocular deprivation to allow normal development of V1 and prevent amblyopia. Studies of animal models of patching therapy for amblyopia reveal that the benefits are both heightened and prolonged by daily episodes of binocular exposure.     

基于fMRI的屈光参差性弱视静息视觉网络的研究

利用静息功能磁共振成像技术,对屈光参差性弱视(anisometropic amblyopia)患者静息态视觉网络进行研究,分析此类患者大脑视觉皮层功能受到的影响。采用独立成分分析(independent component analysis, ICA)这一数据驱动方法对8名屈光参差性弱视患者和11名正常对照的静息数据进行分离,并采用拟合度值(goodness-of-fit scores)分析挑选出静息视觉网络,将结果进行组内分析和组间分析。结果表明,屈光参差性弱视的静息视觉网络中,多级视觉皮层均发生了明显的功能损害,其功能连接度的范围与强度显著低于正常组,而且,高级别纹外皮层比低级别纹状皮层损害更加明显。静息fMRI为深入研究弱视初、高级视觉皮层功能损害的发病机制提供了新的方法。     

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。     

间歇性外斜视患儿的注意跟踪能力异常

间歇性外斜视是儿童眼科的常见疾病之一,也是目前眼科学研究的热点领域之一.本研究使用多物体跟踪实验范式,系统考察了间歇性外斜视儿童,相对于弱视儿童以及正常对照儿童,注意的容量是否存在异常.实验结果发现间歇性外斜视儿童和弱视儿童的注意跟踪能力都显著地差于正常对照儿童,而且间歇性外斜视儿童和弱视儿童的跟踪成绩基本没有差别,他们的注意跟踪功能的受损程度相近.本研究首次报道了间歇性外斜视儿童注意能力的行为异常,对进一步研究间歇性外斜视的发病机理和早期临床诊断具有潜在的参考意义.