Kasa Loxlan W, Donovan Stephanie, Kwon Eryn, Holdsworth Samantha, Schierding William, Danesh-Meyer Helen
Mātai Medical Research Institute, Tairāwhiti Gisborne, New Zealand.
Department of Ophthalmology, The University of Auckland, Auckland, New Zealand.
Front Neurosci. 2025 May 21;19:1577991. doi: 10.3389/fnins.2025.1577991. eCollection 2025.
Glaucoma is a leading cause of blindness globally, with emerging research suggesting that glaucoma-related degeneration may affect the visual pathway. Recent advancements in magnetic resonance imaging (MRI) offer promising non-invasive methods for evaluating glaucoma, including advanced diffusion MRI (dMRI) and computational techniques. One such technique is tractometry, which quantifies white matter (WM) microstructural properties. While the application of tractometry in glaucomatous patients is developing, several key studies have explored structural changes in the brain, particularly within the visual pathways, in individuals with glaucoma. This systematic review comprehensively evaluates the application of tractometry using advanced dMRI models and techniques to quantify WM in the visual pathway of individuals with glaucoma.
PubMed-Medline and PubMed-Central were screened for articles published until April 11th, 2024. The studies based on patient cohorts affected by primary open-angle glaucoma (POAG), primary angle closure glaucoma (PACG), and normal tension glaucoma (NTG) with the following dMRI techniques and tract-specific analysis approach were included in this review: diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), neurite orientation dispersion and density imaging (NODDI), fixel-based analysis (FBA), and dMRI tractometry.
The selected seven studies incorporate tractometry and advanced diffusion models and techniques (DKI, NODDI and FBA), including DTI. Each study investigated microstructural changes along the visual pathway of glaucomatous patients, finding glaucomatous WM degeneration in the optic nerve (ON), optic tract (OT), and optic radiation (OR), as well as significantly altered WM connections between the brain's visual cortex and non-visual areas. Additionally, tractometric findings correlated with clinical measures of glaucoma, such as intraocular pressure, visual field loss, and retinal nerve fiber layer thickness, indicating the potential that changes in tractometric parameters could provide a complementary marker of the disease.
This review enhances our understanding of WM changes in glaucoma and highlights the potential for dMRI tractometry as a promising tool for early detection and monitoring of the disease. By quantifying WM changes, tractometry offers valuable insights not only into the visual pathway but also into brain regions affected by glaucoma. This could lead to more accurate diagnoses, improved tracking of disease progression, and the development of targeted treatment strategies.
青光眼是全球失明的主要原因，新出现的研究表明，青光眼相关的退变可能会影响视觉通路。磁共振成像（MRI）的最新进展为评估青光眼提供了有前景的非侵入性方法，包括先进的扩散MRI（dMRI）和计算技术。其中一种技术是纤维束成像，它可以量化白质（WM）的微观结构特性。虽然纤维束成像在青光眼患者中的应用正在发展，但一些关键研究已经探索了青光眼患者大脑中的结构变化，特别是在视觉通路内。本系统评价全面评估了使用先进的dMRI模型和技术进行纤维束成像，以量化青光眼患者视觉通路中的WM。
对截至2024年4月11日发表的文章进行PubMed-Medline和PubMed-Central检索。本综述纳入了基于受原发性开角型青光眼（POAG）、原发性闭角型青光眼（PACG）和正常眼压性青光眼（NTG）影响的患者队列，采用以下dMRI技术和特定纤维束分析方法的研究：扩散张量成像（DTI）、扩散峰度成像（DKI）、神经突方向离散度和密度成像（NODDI）、基于固定点的分析（FBA）和dMRI纤维束成像。
所选的七项研究纳入了纤维束成像以及先进的扩散模型和技术（DKI、NODDI和FBA），包括DTI。每项研究都调查了青光眼患者视觉通路中的微观结构变化，发现视神经（ON）、视束（OT）和视辐射（OR）存在青光眼性WM退变，以及大脑视觉皮层和非视觉区域之间的WM连接明显改变。此外，纤维束成像结果与青光眼的临床指标相关，如眼压、视野缺损和视网膜神经纤维层厚度，表明纤维束成像参数的变化有可能提供该疾病的补充标志物。
本综述增进了我们对青光眼患者WM变化的理解，并强调了dMRI纤维束成像作为一种有前景的早期检测和监测该疾病工具的潜力。通过量化WM变化，纤维束成像不仅为视觉通路，也为受青光眼影响的脑区提供了有价值的见解。这可能会带来更准确的诊断、改善疾病进展的跟踪以及制定针对性的治疗策略。
