Michelson G, Wärntges S, Engelhorn T, El-Rafei A, Hornegger J, Dörfler A
Augenklinik, Universitätsklinikum Erlangen.
Klin Monbl Augenheilkd. 2012 Feb;229(2):143-8. doi: 10.1055/s-0031-1299262. Epub 2012 Feb 14.
In primary open angle glaucoma (POAG) and its non-barotraumatic subgroup, normal tension glaucoma (NTG), the pathophysiological differences are not clear. A participation of the 4th neuron of the visual pathway (optic radiation) appears possible on the basis of related experimental studies. The goal of the present study was the evaluation of the optic radiation by diffusion tensor imaging (DTI), which is based on the magnetic resonance imaging. The diffusion and anisotropy parameters of the optic radiation as a marker of axonal integrity and demyelination/damage of glial cells, respectively, were used to investigate the relation between the morphology of the papilla (BLDF, linear discriminant function of Burk) and the contrast sensitivity (FDT, frequency doubling test).
In this prospective observational study 13 POAG patients, 13 NTG patients, and 7 control patients of the same mean age were included. For segmentation of the optic radiation a semi-automated algorithm was applied and the diffusion and anisotropy parameters were calculated. The importance of the covariates age, BLDF, and FDT for the DTI parameters was determined using partial correlation analysis.
Analysis of the covariates partially showed a clear autocorrelation. The correlations between the DTI parameters and BLDF were significant in all groups after correction of the measurement values for the covariates. FDT correlated with DTI parameters in controls and POAG. The NTG group did not show this correlation due to a strong spreading of the FDT values.
After statistical elimination of the autocorrelation of the covariates age, BLDF, and FDT the morphology of the papilla correlated with the axonal integrity and demyelination/glia cell impairment of the optic radiation in controls and glaucoma. In NTG the impaired contrast sensitivity is highly variable and is not associated with the condition of the 3rd or 4th neuron, respectively, as compared to POAG. The autocorrelation between individual covariates represents an important element for the judgement of the visual pathway.
在原发性开角型青光眼（POAG）及其非气压性损伤亚组正常眼压性青光眼（NTG）中，病理生理差异尚不清楚。基于相关实验研究，视觉通路的第四神经元（视辐射）可能参与其中。本研究的目的是通过基于磁共振成像的扩散张量成像（DTI）评估视辐射。视辐射的扩散和各向异性参数分别作为轴突完整性和神经胶质细胞脱髓鞘/损伤的标志物，用于研究视乳头形态（BLDF，伯克线性判别函数）与对比敏感度（FDT，频率加倍试验）之间的关系。
在这项前瞻性观察研究中，纳入了13例POAG患者、13例NTG患者和7例平均年龄相同的对照患者。采用半自动算法对视辐射进行分割，并计算扩散和各向异性参数。使用偏相关分析确定协变量年龄、BLDF和FDT对DTI参数的重要性。
协变量分析部分显示出明显的自相关性。在对协变量测量值进行校正后，所有组中DTI参数与BLDF之间的相关性均显著。FDT在对照组和POAG组中与DTI参数相关。由于FDT值的强烈离散，NTG组未显示出这种相关性。
在对协变量年龄、BLDF和FDT的自相关性进行统计学消除后，视乳头形态与对照组和青光眼患者视辐射的轴突完整性及脱髓鞘/神经胶质细胞损伤相关。与POAG相比，NTG中受损的对比敏感度高度可变，且分别与第三或第四神经元的状况无关。个体协变量之间的自相关性是判断视觉通路的重要因素。
