基于空间频率通道的弱视眼与正常眼对比敏感度差异研究

发布时间：2019-01-16 05:43

【摘要】：对比敏感度是衡量人眼在不同空间明暗对比下分辨物像的能力，反映人眼识别空间复杂物体的能力。对比敏感度由空间频率通道进行调谐，空间频率通道调谐曲线的包络构成对比敏感度函数。对比敏感度作为弱视诊断和疗效评价的手段之一，已在临床和科学研究中得到广泛应用。研究弱视眼与正常眼对比敏感度的差异对理解弱视的病理机制及其诊疗具有十分重要的意义。本文通过对174例正常儿童眼和100例儿童弱视眼的对比敏感度数据进行分析，正常眼与弱视眼对比敏感度存在差异，此差异进一步通过“对比敏感度-空间频率通道”模型，得到正常眼和弱视眼的空间频率通道数目相同，并计算通道带宽。为了确保推导出的空间频率通道及其带宽的有效性，，另取独立的48例儿童弱视眼的对比敏感度数据进行交叉验证。从空间频率通道探讨弱视眼和正常眼的对比敏感度存在差异的原因。本文的主要工作如下： 1、首先阐述对比敏感度研究的重要性，综述了国内外取得的研究成果和研究现状，在此基础上提出本文的研究目的和研究内容。 2、借助OPTEC6500视功能测试仪，采用心理物理学方法，设计了对比敏感度检测的实验方案。 3、在浙江大学医学院附属第二医院医院眼科中心，对174例正常儿童眼和148例儿童弱视眼进行眼科检查，详细记录每例受试者的视功能检查数据。 4、对采集到的174例正常眼和100例弱视眼的对比敏感度数据进行统计分析。通过对比敏感度-空间频率通道模型，PCA和Promax旋转推导弱视眼和正常眼的空间频率通道的调谐曲线，利用半高宽法计算通道带宽。空间频率通道的有效性采用独立的48例弱视眼对比敏感度数据进行交叉验证。通过分析弱视眼和正常眼空间频率通道数目及带宽的异同，探讨儿童弱视眼对比敏感度缺损的原因。数据分析结果表明：空间频率为1.5～18.0c/deg时，弱视眼和正常眼均存在3个空间频率通道；空间频率峰值为3.0、6.0、12.0c/deg时，正常眼的通道带宽分别为：1.04、1.03、0.98octaves，弱视眼的通道带宽分别为：1.04、1.02、0.75octaves，表明弱视眼在中、高空间频率的通道带宽比正常眼小，由此推测弱视眼对比敏感度的缺损由对应空间频率通道带宽的减小引起。
[Abstract]:Contrast sensitivity is a measure of the ability of human eyes to distinguish objects under different spatial contrast, reflecting the ability of human eyes to recognize complex objects in space. Contrast sensitivity is tuned by spatial frequency channel, and the envelope of tuning curve of spatial frequency channel constitutes contrast sensitivity function. As one of the methods of amblyopia diagnosis and evaluation, contrast sensitivity has been widely used in clinical and scientific research. It is very important to study the difference of contrast sensitivity between amblyopia and normal eyes in understanding the pathological mechanism and diagnosis and treatment of amblyopia. The contrast sensitivity data of 174 normal children and 100 children with amblyopia were analyzed. The contrast sensitivity of normal eyes and amblyopia eyes was different. The number of spatial frequency channels in normal eyes and amblyopic eyes was the same, and the channel bandwidth was calculated. In order to ensure the validity of the derived spatial frequency channels and their bandwidth, the contrast sensitivity data of 48 children with amblyopia were cross-validated. To explore the causes of difference in contrast sensitivity between amblyopia and normal eyes from spatial frequency channels. The main work of this paper is as follows: 1. Firstly, the importance of contrast sensitivity research is expounded, and the research results and research status at home and abroad are summarized. On the basis of this, the purpose and content of this paper are put forward. 2. With the help of OPTEC6500 visual function tester and psychophysical method, the experimental scheme of contrast sensitivity testing is designed. 3. In the ophthalmology center of the second affiliated Hospital of Zhejiang University Medical College, 174 normal children's eyes and 148 children's amblyopic eyes were examined by ophthalmology. The visual function examination data of each subject were recorded in detail. 4. The contrast sensitivity data of 174 normal eyes and 100 amblyopia eyes were statistically analyzed. The tuning curves of the spatial frequency channels of amblyopia and normal eyes were derived by contrast sensitivity spatial frequency channel model PCA and Promax rotation. The bandwidth of the channel was calculated by using the half height width method. The validity of spatial frequency channels was cross-validated by 48 independent contrast sensitivity data of amblyopic eyes. By analyzing the similarities and differences of spatial frequency channels and bandwidth between amblyopia and normal eyes, the causes of contrast sensitivity defect in amblyopic eyes were discussed. The results of data analysis showed that there were three spatial frequency channels in amblyopia and normal eyes when the spatial frequency was 1.5~18.0c/deg. When the spatial frequency peak value was 3.0 ~ 6.0 ~ 12.0c/ deg, the channel bandwidth of normal eyes was 1.04v 1.03v 0.98octaves. the channel bandwidth of amblyopic eyes was 1.041.02 卤0.75octaves. it indicated that amblyopic eyes were in amblyopia. The channel bandwidth of high spatial frequency is smaller than that of normal eye, so the defect of contrast sensitivity of amblyopia is caused by the decrease of channel bandwidth of corresponding spatial frequency.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R777.44

【参考文献】