不同类型原发性青光眼的扩散张量成像研究

The study of different kinds of primary glaucoma by diffusion tensor imaging

目的探讨不同类型原发性青光眼视觉通路白质纤维束扩散张量成像(diffusion tensor imaging,DTI)特征及其与青光眼严重程度相关性。材料与方法收集慢性闭角型青光眼(chronic angle-closure glaucoma,CACG)、急性闭角型青光眼(acute angle-closure glaucoma,AACG)、开角型青光眼(primary open-angle glaucoma,POAG)各10例(每组20只眼);正常对照组10例(20只眼)。行视野平均缺损(mean defect,MD)及磁共振DTI检查,测量并比较各组视神经、视辐射区部分各向异性(fractional anisotropy,FA)、平均扩散系数(average diffusion coefficient,ADC),并行统计学分析。结果CACG、AACG、POAG视神经区FA值低于自身视辐射区(P<0.05),正常对照组视神经与自身视辐射FA值差异无统计学意义(P>0.05);与正常对照组相比,三组青光眼双侧视神经、视辐射FA值降低(P<0.05),CACG、AACG双侧视神经及AACG右侧视辐射ADC值升高(P<0.05);AACG右侧视神经FA值较CACG、POAG为低(P=0.015、0.005),AACG双侧视神经ADC值较POAG为高(P=0.011、0.040),AACG右侧视辐射ADC值较POAG为高(P=0.003);CACG、AACG右侧视神经FA值与MD呈正相关(r=0.844,P=0.002;r=0.648,P=0.043)。结论DTI能够量化评价原发性青光眼视神经纤维通路的微观损伤,可为青光眼早期诊断、疗效评价提供信息。

Objective:To evaluate the microscopic changes of optic pathway in different kinds of primary glaucoma by diffusion tensor imaging(DTI),and investigate the relationship to the severity of glaucoma.Materials and Methods:There were 10 cases(20 eyes in each group)in each group of chronic angle-closure glaucoma(CACG),acute angle-closure glaucoma(AACG)and primary open-angle glaucoma(POAG).And 10 cases(20 eyes)of control subjects were recruited in this study.The mean defect(MD)of view was checked.All subjects underwent DTI examination.The fractional anisotropy(FA),average diffusion coefficient(ADC)of optic nerve and optic radiation were measured by MR post-processing software and were analyzed statistically.All these were analyzed by SPSS 22.0.Results:FA of optic nerve were lower than that of optic radiation in CACG,AACG and POAG(P<0.05).There were no significant statistical difference in control group(P>0.05).FA of optic nerves and optic radiation in group CACG,AACG and POCG were significantly lower than the controls(P<0.05).The ADC values of optic nerve in group CACG,AACG and the right optic radiation in AACG were significantly higher than controls(P<0.05).FA of right optic nerves in group AACG were significantly lower than group CACG and POAG(P=0.015,0.005),ADC of optic nerves in group AACG were higher than group POAG(P=0.011,0.040),ADC of right optic radiation in group AACG were higher than group POAG(P=0.003).FA of right optic nerve in CACG and AACG were positively correlated with MD(r=0.844,P=0.002;r=0.648,P=0.043).Conclusions:The parameters of DTI reflected the microstructures of the optic pathway in different kinds of primary glaucoma,which wouldbe helpful in the diagnosis,curative effect evaluation of glaucoma.