眼底老化是年龄相关性黄斑变性(age-related macular degeneration, AMD)发生和进展的关键因素及病理基础，在组织病理学上主要表现为脉络膜毛细血管萎缩、布鲁赫膜(Bruch's membrane, BrM)增厚以及视网膜色素上皮(retinal pigment epithelium, RPE)异常。BrM增厚可由多种眼底老化沉积物聚集引起，在AMD的病理机制中具有重要作用。其中，基底薄层沉积物(basal laminar deposit, BLamD)代表了RPE基底膜的弥漫性增厚，通常作为一种正常眼底老化改变。而以酯化和未酯化胆固醇等中性脂质为主的RPE基底膜下沉积物，即基底线性沉积物(basal linear deposits, BLinD)和软性玻璃膜疣，均可参与破坏脉络膜与外层视网膜间物质交换稳态，造成外层视网膜缺血、缺氧及氧化应激，是AMD早期重要病理改变。硬性玻璃膜疣主要分布于周边视网膜，多见于正常老化眼底；表皮玻璃膜疣是RPE基底膜局灶性结节状增厚的结果，眼底表现与硬性玻璃膜疣相似，但其主要分布于后极部，数量更多且密度更高。近年来逐渐加深了对视网膜下玻璃膜疣样沉积物(subretinal drusenoid deposit, SDD)的认识和研究，其是位于RPE上方的沉积物，在AMD发病机制中亦具有深刻意义。文章就几种眼底老化相关沉积物(包括硬性玻璃膜及表皮玻璃膜疣)的病理特征和多模态影像学表现进行综述，旨在帮助认识和理解这些沉积物的眼底表现、病理特征和形成机制，以及在AMD发生及进展中的临床意义。
Fundus aging is a key factor and pathological basis for the development and progression of age-related macular degeneration (AMD), which is histopathologically characterized by choroidal capillary atrophy, Bruch’s membrane (BrM) thickening, and abnormalities of retinal pigment epithelium (RPE). BrM thickening can be induced by the aggregation of age-related fundus deposits and plays an essential role in the pathogenesis of AMD. Basal laminar deposits (BLamD) represent diffuse thickening of the basement membrane of RPE, usually considered to be a normal fundus aging. Basal linear deposits (BLinD) and soft drusen, mainly composed of neutral lipids such as esterified and unesterified cholesterol, can disrupt the homeostasis of material exchange between the choroid and the outer retina, resulting in ischemia, hypoxia, and oxidative stress in the outer retina, which are important pathological changes in the early AMD. Hard drusen is mainly distributed in the peripheral retina and is very common in aging fundus; Cuticular drusen are resulted from focal nodular thickening of the basement membrane of RPE, with similar appearance as hard drusen, but mainly distributed in the posterior pole and more numerous and denser. Recently, our understanding of subretinal drusenoid deposits (SDD), deposits above the RPE, has been gradually deepened and it also has profound significance in the pathogenesis of AMD. In this review, we presented the pathologic features and multimodal imaging of age-related fundus deposits (including hard drusen and cuticular drusen), aiming to help recognize and understand the manifestations, pathologic features, and formation mechanisms of these deposits, as well as their clinical significance in the development and progression of AMD.
目的：获取眼表图像的综合信息，建立眼表疾病综合诊断和评估。方法：将超高分辨率光学相干断层成像仪(ultra-high resolution optical coherence tomography，UHR-OCT)与基于裂隙灯生物显微镜的微血管成像系统相结合，开发了一种多模态、非接触式的眼科光学成像平台。结果：UHR-OCT模块在组织中实现轴向分辨率约为2 μm 。眼表微血管成像模块在最大放大倍率下横向分辨率约为3.5 μm。通过集成在裂隙灯显微镜成像光学路径的不同模块，多模态成像平台能够执行实时前段OCT结构成像、结膜微血管成像和传统裂隙灯成像功能。利用自主开发的软件，进一步分析结膜血管网络图像和血流图像，获取血管分形维数、血流速度、血管直径等定量形态学和血流动力学参数。结论：通过在健康受试者和角膜炎患者的在体成像测试，表明多模态眼前段成像设备可为眼科临床应用及人工智能提供结构和功能信息数据。
Objective: To obtain the comprehensive information of the anterior eye image, establish complementary information for the diagnosis and evaluation of ocular diseases. Methods: We developed a multi-modal, non-invasive optical imaging platform by combining ultra-high resolution optical coherence tomography (UHR-OCT) with a microvascular imaging system based on slit-lamp biomicroscopy. Results: The uHR-OCT module achieved an axial resolution of approximately 2 μm in tissues. The lateral resolution of the ocular surface microvascular imaging module under maximum magnification was approximately 3.5 μm. By combining the imaging optical paths of different modules, the customized multi-modal eye imaging platform was capable of performing real-time cross-sectional UHR-OCT imaging of the anterior eye, conjunctival vessel network imaging, high-resolution conjunctival blood flow videography, and traditional slit-lamp imaging on a single device. With self-developed software, a conjunctival vessel network image and blood flow videography were further analyzed to acquire quantitative morphological and hemodynamics parameters, including vessel fractal dimensions, blood flow velocity and vessel diameters. Conclusion: The ability of the multi-modal anterior eye imager to provide both structural and functional information for ophthalmic clinical applications can be demonstrated in a healthy human subject and a keratitis patient.
