屈光参差性弱视视放射及胼胝体的扩散张量成像研究

摘要

Objective To evaluate the development of optic radiations ( ORs) and corpus callosum in children with anisometropic amblyopia by using diffusion tensor imaging (DTI) ,and to explore the underlying mechanism of patho-genesis of amblyopia. Methods Fourteen children with anisometropic amblyopia ( all left eyes) and 30 normally sighted children underwent DTI scanning. The fractional anisotropy (FA) values and the apparent diffusion coefficient ( ADC) values of ORs and corpus callosum were measured . Comparisons of FA values and ADC values were made both within the groups (Left to Right comparison) and between the two groups. Results In both groups , the FA values of left ORs were higher than those of right ORs and the ADC values of left ORs were lower than those of right ORs ( P < 0. 05 ). The FA values of ORs in children with amblyopia were lower than those of ORs in children with normal sights ( P <0. 05) , while the ADC values of ORs were higher ( P <0. 05 ). And the ADC values of splenium corporis callosi in children with ambly -opia were higher than those of splenium corporis callosi in children with normal sights ( P < 0. 05). Conclusion The difference between the anisometropic amblyopia and the normal controls reflect the underdevelopment of ORs and splenium corporis callosi in children with anisometropic amblyopia .%目的 利用磁共振扩散张量成像技术(DTI)检测屈光参差性弱视儿童视觉通路中视放射及胼胝体的发育情况,从而探讨其发病机制.方法 采集14例左眼屈光参差性弱视儿童和30例正常对照儿童DTI数据,分别测定弱视组和对照组两侧视放射及胼胝体的各向异性分数(FA)值、表观扩散系数(ADC)值,并进行比较分析.结果 左眼弱视组和正常对照组均表现为左侧视放射的FA值高于右侧(P<0.05),ADC值低于右侧(P<0 05).组间分析,左眼弱视组两侧视放射的FA值均低于正常对照组(P<0.05),ADC值均高于正常对照组(P<0.05),胼胝体压部ADC值高于正常对照组(P<0.05).结论 屈光参差性弱视儿童的视放射及胼胝体压部的FA和ADC值与正常对照组比较差异有统计学意义,提示其神经纤维存在一定程度的发育不良,可能是屈光参差性弱视儿童单眼及双眼视功能低下的机制之一.