Department of Ophthalmology, The Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8461, Japan.
Department of Ophthalmology, Atsugi City Hospital, Kanagawa, Japan.
Brain Struct Funct. 2018 Nov;223(8):3889-3900. doi: 10.1007/s00429-018-1702-5. Epub 2018 Jun 27.
We investigated the impact of age-related macular degeneration (AMD) on visual acuity and the visual white matter. We combined an adaptive cortical atlas and diffusion-weighted magnetic resonance imaging (dMRI) and tractography to separate optic radiation (OR) projections to different retinal eccentricities in human primary visual cortex. We exploited the known anatomical organization of the OR and clinically relevant data to segment the OR into three primary components projecting to fovea, mid- and far-periphery. We measured white matter tissue properties-fractional anisotropy, linearity, planarity, sphericity-along the aforementioned three components of the optic radiation to compare AMD patients and controls. We found differences in white matter properties specific to OR white matter fascicles projecting to primary visual cortex locations corresponding to the location of retinal damage (fovea). Additionally, we show that the magnitude of white matter properties in AMD patients' correlates with visual acuity. In sum, we demonstrate a specific relation between visual loss, anatomical location of retinal damage and white matter damage in AMD patients. Importantly, we demonstrate that these changes are so profound that can be detected using magnetic resonance imaging data with clinical resolution. The conserved mapping between retinal and white matter damage suggests that retinal neurodegeneration might be a primary cause of white matter degeneration in AMD patients. The results highlight the impact of eye disease on brain tissue, a process that may become an important target to monitor during the course of treatment.
我们研究了年龄相关性黄斑变性 (AMD) 对视力和视觉白质的影响。我们结合自适应皮质图谱和弥散加权磁共振成像 (dMRI) 和轨迹追踪技术，将视辐射 (OR) 投射到人类初级视觉皮层中不同视网膜偏心度的投影分离出来。我们利用 OR 的已知解剖结构和临床相关数据，将 OR 分割成三个主要成分，分别投射到中央凹、中周和远周。我们测量了 OR 三个主要成分上的白质组织特性——各向异性分数、线性度、平面度和球形度，以比较 AMD 患者和对照组。我们发现，与投射到初级视觉皮层视网膜损伤部位（中央凹）相对应的 OR 白质束的白质特性存在差异。此外，我们还表明，AMD 患者的白质特性与视力相关。总之，我们证明了在 AMD 患者中，视力丧失、视网膜损伤的解剖位置与白质损伤之间存在特定关系。重要的是，我们证明这些变化非常显著，使用具有临床分辨率的磁共振成像数据即可检测到。视网膜和白质损伤之间的保守映射表明，视网膜神经退行性变可能是 AMD 患者白质退化的主要原因。研究结果强调了眼部疾病对脑组织的影响，这一过程可能成为治疗过程中监测的一个重要目标。
