Ogawa Shumpei, Takemura Hiromasa, Horiguchi Hiroshi, Terao Masahiko, Haji Tomoki, Pestilli Franco, Yeatman Jason D, Tsuneoka Hiroshi, Wandell Brian A, Masuda Yoichiro
Department of Psychology, Stanford University, Stanford, California, United States Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan.
Department of Psychology, Stanford University, Stanford, California, United States Department of Psychology, The University of Tokyo, Tokyo, Japan.
Invest Ophthalmol Vis Sci. 2014 Sep 25;55(10):6976-86. doi: 10.1167/iovs.14-14737.
Patients with Leber hereditary optic neuropathy (LHON) and cone-rod dystrophy (CRD) have central vision loss; but CRD damages the retinal photoreceptor layer, and LHON damages the retinal ganglion cell (RGC) layer. Using diffusion MRI, we measured how these two types of retinal damage affect the optic tract (ganglion cell axons) and optic radiation (geniculo-striate axons).
Adult onset CRD (n = 5), LHON (n = 6), and healthy controls (n = 14) participated in the study. We used probabilistic fiber tractography to identify the optic tract and the optic radiation. We compared axial and radial diffusivity at many positions along the optic tract and the optic radiation.
In both types of patients, diffusion measures within the optic tract and the optic radiation differ from controls. The optic tract change is principally a decrease in axial diffusivity; the optic radiation change is principally an increase in radial diffusivity.
Both photoreceptor layer (CRD) and retinal ganglion cell (LHON) retinal disease causes substantial change in the visual white matter. These changes can be measured using diffusion MRI. The diffusion changes measured in the optic tract and the optic radiation differ, suggesting that they are caused by different biological mechanisms.
患有Leber遗传性视神经病变（LHON）和视锥视杆营养不良（CRD）的患者会出现中心视力丧失；但CRD会损害视网膜光感受器层，而LHON会损害视网膜神经节细胞（RGC）层。我们使用扩散磁共振成像（MRI）来测量这两种类型的视网膜损伤如何影响视束（神经节细胞轴突）和视辐射（膝状体-纹状体轴突）。
成年发病的CRD患者（n = 5）、LHON患者（n = 6）和健康对照者（n = 14）参与了该研究。我们使用概率纤维束成像来识别视束和视辐射。我们比较了沿视束和视辐射多个位置的轴向扩散率和径向扩散率。
在这两种类型的患者中，视束和视辐射内的扩散测量值与对照者不同。视束的变化主要是轴向扩散率降低；视辐射的变化主要是径向扩散率增加。
光感受器层（CRD）和视网膜神经节细胞（LHON）的视网膜疾病都会导致视觉白质发生显著变化。这些变化可以使用扩散MRI进行测量。视束和视辐射中测量到的扩散变化不同，表明它们是由不同的生物学机制引起的。
