OCTA应用于糖尿病视网膜病变的研究进展

糖尿病视网膜病变（DR）是糖尿病的一种常见并发症,其破坏视网膜微血管,是全球眼病患者视力下降的主要原因。目前,检测DR的金标准是眼底荧光素血管造影（FFA）技术。随着光学相干断层血管造影成像（OCTA）的出现,其提供了一种快速、安全的方法来评估视网膜微血管系统,比传统的荧光血管造影具有更高的对比度和分辨率。高质量的OC...     

光学相干断层扫描血管成像在DR中的诊疗进展

光学相干断层扫描成像(OCT)是眼科影像学中发展最快的技术之一。随着OCT技术逐步改良更新,光学相干断层扫描血管成像(OCTA)随之出现,OCTA在视网膜和脉络膜血流成像中能为多种眼底血管性疾病提供诊疗价值。本文综述了OCTA的原理,以及OCTA观察糖尿病患者眼底的微动脉瘤(MAs)、视网膜缺血、视网膜新生血管(RNV)及其在DR各期组织病理改变的特征、OCTA的局限性及其发展前景。     

Optical coherence tomography angiography: A comprehensive review of current methods and clinical applications

OCT has revolutionized the practice of ophthalmology over the past 10–20 years. Advances in OCT technology have allowed for the creation of novel OCT-based methods. OCT-Angiography (OCTA) is one such method that has rapidly gained clinical acceptance since it was approved by the FDA in late 2016. OCTA images are based on the variable backscattering of light from the vascular and neurosensory tissue in the retina. Since the intensity and phase of backscattered light from retinal tissue varies based on the intrinsic movement of the tissue (e.g. red blood cells are moving, but neurosensory tissue is static), OCTA images are essentially motion-contrast images. This motion-contrast imaging provides reliable, high resolution, and non-invasive images of the retinal vasculature in an efficient manner. In many cases, these images are approaching histology level resolution. This unprecedented resolution coupled with the simple, fast and non-invasive imaging platform have allowed a host of basic and clinical research applications. OCTA demonstrates many important clinical findings including areas of macular telangiectasia, impaired perfusion, microaneurysms, capillary remodeling, some types of intraretinal fluid, and neovascularization among many others. More importantly, OCTA provides depth-resolved information that has never before been available. Correspondingly, OCTA has been used to evaluate a spectrum of retinal vascular diseases including diabetic retinopathy (DR), retinal venous occlusion (RVO), uveitis, retinal arterial occlusion, and age-related macular degeneration among others. In this review, we will discuss the methods used to create OCTA images, the practical applications of OCTA in light of invasive dye-imaging studies (e.g. fluorescein angiography) and review clinical studies demonstrating the utility of OCTA for research and clinical practice.     

光学相干断层扫描血流成像技术(OCTA)在视网膜静脉阻塞中的应用

光学相干断层扫描血管成像技术(optical coherence tomography angiography,OCTA)是一种近年来新兴的无创、快速、高分辨率的眼底血管成像技术.OCTA拥有分层观察不同层面的视网膜血管形态,量化血流灌注的独特优势,现广泛应用于各类眼底血管疾病的诊断及随访.视网膜静脉阻塞是一种常见的眼底血管病变,本文对OCTA在视网膜静脉阻塞的应用进行综述.     

Application of optical coherence tomography angiography in diabetic retinopathy: a comprehensive review

Optical coherence tomography angiography (OCTA) is a noninvasive method that enables visualization of blood flow within retinal vessels down to the size of capillaries by detecting motion contrast from moving blood cells. OCTA provides a fast and safe procedure to assess retinal microvasculature with higher contrast and resolution than conventional fluorescence angiography. The different capillary plexuses are displayed separately and their perfusion density can be quantified. Imaging capabilities such as these have led to an emerging field of clinical application for OCTA in vascular diseases such as diabetic retinopathy (DR). Evaluation of parameters such as parafoveal capillary perfusion density could be a biomarker for disease diagnosis and progression. Typical microvascular changes in DR such as capillary nonperfusion, microaneurysms, intraretinal microvascular abnormalities, and neovascularization can be reliably detected in optical coherence tomography angiograms, characterized in detail and attributed to the different capillary plexuses. Monitoring of these lesions in vivo gives potential novel insight into the pathophysiology in DR. The aim of this article is to summarize the potential applications/utility of OCTA in DR reported in the literature.     

Fluorescein and OCT Angiography Features of Takayasu Disease

Purpose: Evaluate OCT (optical coherence tomography) angiography (OCTA) features in patients with Takayasau disease.

Methods: The OCTA was analyzed to evaluate perifoveal anastomatic capillary arcade disruption, microaneurysms. The foveal avascular zone (FAZ) was measured for superficial (SCP) and deep capillary plexus.

Results: There were 26 eyes included. In OCTA, 11 eyes presented ruptures of the perifoveal anastomotic capillary arcade in SCP. A total of 5 had microaneurysms. The average SCP FAZ was increased to 0.34 mm2 in Takayasu compared to 0.27 mm2 in control patients.

Conclusion: Fluorescein angiography is the gold standard to describe Takayasu retinopathy ischemic signs. Macular abnormalities are uncommon in Takayasu patients as retinopathy signs are mostly located in peripheral retina. This study reveals that most of our patients present an enlargement of the FAZ then highlights the relevance of OCTA to evaluate macular ischemia as a complement to usual retina global study in fluorescein angiography.     

Visualization of microaneurysms using optical coherence tomography angiography: comparison of OCTA en face,OCT B-scan,OCT en face,FA, and IA images

Purpose

To compare the visualization of microaneurysms (MAs) in patients with diabetic retinopathy (DR) using optical coherence tomography angiography (OCTA) with that using fluorescein angiography (FA).

Study design

Prospective, clinical, and experimental.

Methods

This study was a prospective evaluation of imaging technology. Thirty-seven eyes of 33 patients with DR were scanned using an OCTA instrument. The 83 MAs that were confirmed on OCT B-scan and OCT en face images were evaluated using OCTA, and these findings were compared with those evaluated using FA.

Results

Of the 83 MAs confirmed on OCT B-scan images, 73 (88%) were clearly visualized on the OCTA en face images as nodular or comma-shaped structures, while the remaining 12% did not present with a typical MA or vascular structure on the OCTA en face images at the relevant positions. Seventy-four of the 83 MAs (87%) confirmed on the OCT B-scan images presented as punctate hyperfluorescent spots on the FA images. On the FA images, 8 of 9 (88%) MAs absent on the OCTA en face images presented as hyperfluorescent spots. Visualization of the MAs on the OCTA en face images did not correlate with the OCT B-scan images of the MA lumens (open, closed, or heterogeneous).

Conclusions

For diabetic maculopathy, OCTA en face images do not present with comprehensive MAs images, indicating that some MAs might be overlooked with OCTA en face images.

     

Artificial intelligence in OCT angiography

Optical coherence tomographic angiography (OCTA) is a non-invasive imaging modality that provides three-dimensional, information-rich vascular images. With numerous studies demonstrating unique capabilities in biomarker quantification, diagnosis, and monitoring, OCTA technology has seen rapid adoption in research and clinical settings. The value of OCTA imaging is significantly enhanced by image analysis tools that provide rapid and accurate quantification of vascular features and pathology. Today, the most powerful image analysis methods are based on artificial intelligence (AI). While AI encompasses a large variety of techniques, machine-learning-based, and especially deep-learning-based, image analysis provides accurate measurements in a variety of contexts, including different diseases and regions of the eye. Here, we discuss the principles of both OCTA and AI that make their combination capable of answering new questions. We also review contemporary applications of AI in OCTA, which include accurate detection of pathologies such as choroidal neovascularization, precise quantification of retinal perfusion, and reliable disease diagnosis.     

Application of optical coherence tomography angiography in ocular anterior segment diseases北大核心CSCD

Optical coherence tomography angiography (OCTA) is a rapid, noninvasive new blood flow imaging technique that was first applied to retinal retinopathy and acquired retinal vascular imaging in only a few seconds. Compared with the traditional optical coherence tomography(OCT), OCTA analyze has the advantages of higher resolution, faster scanning speed, quantitative blood flow, etc. OCTA not only can more accurately and qualitatively analyze ocular vascular morphology, but also can measure blood vessels and blood flow perfusion noninvasively and quantitatively. With the application of anti angiogenesis drugs in the anterior segment, it is important to evaluate the neovascularization of the cornea and iris in order to guide the clinical medication and evaluate the therapeutic effect. This article reviewed the application of OCTA in ocular anterior segment diseases, such as cornea and iris diseases, etc. Copyright © 2018 by the Chinese Medical Association.     

光学相干断层扫描血管成像技术在糖尿病视网膜病变中的应用

光学相干断层扫描血管成像技术( optical coherence tomography angiography,OCTA)是近年来光学相干断层扫描( optical coherence tomography,OCT)的新兴技术,是一种无创、快速、高分辨率的眼底血管成像技术,现已被逐渐应用于各类眼底血管疾病的诊治及随访,如糖尿病视网膜病变、脉络膜新生血管等。 OCTA拥有能分层观察不同层面的视网膜脉络膜血管结构及形态和量化一定范围内的血流指数及病灶血流面积的独特优势。但OCTA存在观察视网膜范围有限、观察视网膜血管屏障功能有限、要求高固视力高配合度等不足,如果克服这些局限,将有助于我们提升对视网膜血管疾病的认识,完善对视网膜血管疾病的诊治和观察。     

Role of OCT Angiography in the Detection of Retinal Vascular and Macular Abnormalities in Subjects with Asteroid Hyalosis

Purpose: To study the role of Optical coherence tomography (OCT) Angiography (OCTA) in detecting retinal vascular and macular abnormalities as compared to Fundus Fluorescein Angiography (FFA) in subjects with Asteroid hyalosis (AH).

Methods: In a prospective study, patients with AH underwent OCTA and FFA. AH graded as Grade 1 in 8 (optic disc, second order vessels visible), Grade 2 in 4 (optic disc, first-order vessels visible), Grade 3 in 11 (hazy view of optic disc) and Grade 4 (no view of fundus) in 2 eyes.

Results: A total of 20 patients (25 eyes) with AH were included. In comparison to FFA, OCTA was able to similarly detect Diabetic Retinopathy changes such as Neovascularization, microaneurysms, capillary dropout, and foveal avascular zone extent in vascular occlusion in all grades of AH.

Conclusion: OCTA, a noninvasive imaging tool, could detect various retinal vascular and macular abnormalities in patients with all grades of AH in comparison to FFA.     

OCTA对年龄相关性黄斑变性的诊断评价及图像特征分析

光学相干断层血管造影(OCTA)是一种快速、无创的成像方法,可以提供视网膜和脉络膜的实时血流信息。与传统的血管造影相比较,OCTA可以产生更详细、更高分辨率的血管图像,而不增加造影剂相关风险。年龄相关性黄斑变性(ARMD)是全球主要的老年性致盲眼病,OCTA能很好地显示脉络膜新生血管的影像,为ARMD的早期诊断及干预提供可能。本文将对OCTA在ARMD的相关图像特征及其诊断价值进行综述。     

Practical guidance for imaging biomarkers in exudative age-related macular degeneration

We provide an overview of current macular imaging techniques and identify and describe biomarkers that may be of use in the routine management of macular diseases, particularly exudative age-related macular degeneration (AMD). This perspective includes sections on macular imaging techniques including optical coherence tomography (OCT) and OCT angiography (OCTA), classification of exudative AMD, and biomarkers in structural OCT and OCTA.Fluorescein angiography remains a vital tool for assessing the activity of neovascular lesions, while indocyanine green angiography is the preferred option for choroidal vessel imaging in neovascular AMD. OCT provides a non-invasive three-dimensional visualization of retinal architecture in vivo and is useful in the diagnosis of many imaging biomarkers of AMD-related neovascular lesions, including lesion activity. OCTA is a recent advance in OCT technology that allows accurate visualization of retinal and choroidal vascular flow. OCT and OCTA have led to an updated classification of exudative AMD lesions and provide several biomarkers that help to establish a diagnosis and the disease activity status of neovascular lesions.Individualization of therapy guided by OCT and OCTA biomarkers has the potential to further improve visual outcomes in exudative AMD. Moving forwards, integration of technologically-advanced imaging equipment with AI software will help ophthalmologists to provide patients with the best possible care.     

重视光相干断层扫描血流成像的临床应用及其图像的判读

光相干断层扫描血流成像(OCTA)是在OCT的基础上发展而来的眼病诊断新技术,也是目前眼科影像学检查中发展最快速的检查方法之一.目前,对眼底血管性疾病的主要检查方法包括荧光素眼底血管造影(FFA)和吲哚青绿血管造影(ICGA),具有对血管异常动态显现的特点,能对异常血管形态和病变特征提供有用的诊断信息,但其为有创的检查方法,且无法对病变进行分层分析.与FFA和ICGA相比,OCTA除了具备无创、快速、高分辨率的特点外,还具有无创性对血流显影的能力,其不受血管渗漏和视网膜出血的影响,能够提供三维测量的病变图像,并能实现病变的定量检测和分层检测,目前已用于多种眼科疾病的诊断和病情监测.OCTA技术的临床应用丰富了眼科影像学对疾病的诊疗信息及发病机制的探索结果.OCTA的检测过程和正确判读是基于对其原理和眼部待测组织解剖知识的理解和掌握,因此理解其原理及临床应用是临床眼科医师的必修课程.     

光学相干断层扫描血管成像在糖尿病微血管病变中的应用

糖尿病视网膜病变(DR)和糖尿病肾病(DN)是糖尿病患者最常见、最严重的两大微血管并发症，是引起致盲和终末期肾病的主要原因。视网膜血管是糖尿病早期常见的损害靶点，也是人体血管系统中唯一可直视的活体血管，其形态结构或功能的变化可直接或间接反映糖尿病引起的微血管病变。特别是近年来光学相干断层扫描血管成像(OCTA)这一新型、无创技术的发展，在血管成像分辨率、血管深度以及血管形态方面都有新的突破，并能提供客观的定量数据，在糖尿病微血管病变中具有一定应用价值。因此，本文旨在对OCTA及其在糖尿病微血管病变中的应用作一综述。     

OCTA测量近视人群视网膜血管密度及中心凹无血管区的研究进展

光学相干断层扫描血管成像（OCTA）作为近几年不断发展的一项新兴技术,可以快速无创地得到高分辨率的眼底视网膜成像,并可以得到眼底血管密度及中心凹无血管区面积的量化值,为研究近视疾病早期的眼底病变提供极大帮助。现回顾OCTA的发展史,详细介绍并总结OCTA测量近视人群眼底视网膜血流变化及其影响因素,及辅助病理性近视诊断的...     

A Review of OCT Angiography in Glaucoma

ABSTRACT

There is growing evidence that vascular dysfunction plays a role in the pathogenesis of glaucoma. The details of this relationship have remained elusive partially due to limitations in our ability to assess blood flow in the optic nerve. Optical coherence tomography angiography (OCTA) has emerged as a promising new technology well positioned to become the first clinically suitable test of optic nerve perfusion. OCTA uses the motion of red blood cells as an intrinsic contrast agent to create reproducible images of microvascular networks rapidly and non-invasively. A significant body of research regarding the use of OCTA in glaucoma has emerged in recent years. This review aims to provide an overview of the basic principles underlying OCTA technology, summarize the current literature regarding the application of OCTA in the management of glaucoma, and address the role of OCTA in explicating the vascular pathogenesis of glaucoma.     

Multimodal imaging of experimental choroidal neovascularization

AIM: To compare choroidal neovascularization (CNV) lesion measurements obtained by in vivo imaging modalities, with whole mount histological preparations stained with isolectin GS-IB4, using a murine laser-induced CNV model. METHODS: B6N.Cg-Tg(Csf1r-EGFP)1Hume/J heterozygous adult mice were subjected to laser-induced CNV and were monitored by fluorescein angiography (FA), multicolor (MC) fundus imaging and optical coherence tomography angiography (OCTA) at day 14 after CNV induction. Choroidal-retinal pigment epithelium (RPE) whole mounts were prepared at the end of the experiment and were stained with isolectin GS-IB4. CNV areas were measured in all different imaging modalities at day 14 after CNV from three independent raters and were compared to choroidal-RPE whole mounts. Intraclass correlation coefficient (ICC) type 2 (2-way random model) and its 95% confidence intervals (CI) were calculated to measure the correlation between different raters'' measurements. Spearman''s rank correlation coefficient (Spearman''s r) was calculated for the comparison between FA, MC and OCTA data and histology data. RESULTS: FA (early and late) and MC correlates well with the CNV measurements ex vivo with FA having slightly better correlation than MC (FA early Spearman''s r=0.7642, FA late Spearman''s r=0.7097, and MC Spearman''s r=0.7418), while the interobserver reliability was good for both techniques (FA early ICC=0.976, FA late ICC=0.964, and MC ICC=0.846). In contrast, OCTA showed a poor correlation with ex vivo measurements (Spearman''s r=0.05716) and high variability between different raters (ICC=0.603). CONCLUSION: This study suggests that FA and MC imaging could be used for the evaluation of CNV areas in vivo while caution must be taken and comparison studies should be performed when OCTA is employed as a CNV monitoring tool in small rodents.