Chan Karen K W, Tang Fangyao, Tham Clement C Y, Young Alvin L, Cheung Carol Y
Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital and Alice Ho Miu Ling Nethersole Hospital, Hong Kong, China.
BMJ Open Ophthalmol. 2017 Jul 11;1(1):e000032. doi: 10.1136/bmjophth-2016-000032. eCollection 2017.
Despite the critical impact of glaucoma on global blindness, its aetiology is not fully characterised. Elevated intraocular pressure is highly associated with glaucomatous optic neuropathy. However, visual field loss still progresses in some patients with normal or even low intraocular pressure. Vascular factors have been suggested to play a role in glaucoma development, based on numerous studies showing associations of glaucoma with blood pressure, ocular perfusion pressure, vasospasm, cardiovascular disease and ocular blood flow. As the retinal vasculature is the only part of the human circulation that readily allows non-invasive visualisation of the microcirculation, a number of quantitative retinal vascular parameters measured from retinal photographs using computer software (eg, calibre, fractal dimension, tortuosity and branching angle) are currently being explored for any association with glaucoma and its progression. Several population-based and clinical studies have reported that changes in retinal vasculature (eg, retinal arteriolar narrowing and decreased fractal dimension) are associated with optic nerve damage and glaucoma, supporting the vascular theory of glaucoma pathogenesis. This review summarises recent findings on the relationships between quantitatively measured structural retinal vascular changes with glaucoma and other markers of optic nerve head damage, including retinal nerve fibre layer thickness. Clinical implications, recent new advances in retinal vascular imaging (eg, optical coherence tomography angiography) and future research directions are also discussed.
尽管青光眼对全球失明情况有着严重影响，但其病因尚未完全明确。眼压升高与青光眼性视神经病变高度相关。然而，在一些眼压正常甚至偏低的患者中，视野缺损仍会进展。基于大量显示青光眼与血压、眼灌注压、血管痉挛、心血管疾病及眼血流量之间存在关联的研究，血管因素被认为在青光眼的发展过程中起作用。由于视网膜血管系统是人体循环中唯一易于对微循环进行无创可视化的部分，目前正在探索使用计算机软件从视网膜照片测量得到的一些定量视网膜血管参数（例如管径、分形维数、迂曲度和分支角度）与青光眼及其进展之间的任何关联。多项基于人群的研究和临床研究报告称，视网膜血管系统的变化（例如视网膜小动脉变窄和分形维数降低）与视神经损伤和青光眼相关，这支持了青光眼发病机制的血管学说。本综述总结了关于定量测量的视网膜血管结构变化与青光眼以及视神经乳头损伤的其他标志物（包括视网膜神经纤维层厚度）之间关系的最新研究结果。还讨论了临床意义、视网膜血管成像的最新进展（例如光学相干断层扫描血管造影）以及未来的研究方向。
