Ultra-wide-field fluorescein angiography of the ocular fundus

PURPOSE: To evaluate the clinical applicability of a novel scanning laser ophthalmoscopy imaging system for ultra-wide-field fluorescein angiography. DESIGN: Observational case report. METHODS: Wide-field fluorescein angiography images were captured in normal volunteers and in patients with a variety of clinical disorders with a newly developed scanning laser ophthalmoscope (Optomap; Optos PLC., Dunfermline, Scotland, United Kingdom) that produces high-resolution images of the fundus up to a 200-degree field. Fluorescein angiograms were performed using standard sequence times. RESULTS: Peripheral vascular perfusion of all four quadrants of a normal fundus was observed with good detail of the capillary architecture. Patients with diabetes and ocular inflammatory eye disease showed evidence of peripheral retinal nonperfusion. The relative degrees of retinal perfusion and nonperfusion could be compared in single images. CONCLUSIONS: Ultra-wide-field fundus fluorescein angiography offers the possibility of evaluating and quantitating peripheral retinal perfusion and vascular pathology in fundus disease.     

Anterior segment imaging in glaucoma: An updated review

Anterior segment imaging allows for an objective method of visualizing the anterior segment angle. Two of the most commonly used devices for anterior segment imaging include the anterior segment optical coherence tomography (AS-OCT) and the ultrasound biomicroscopy (UBM). AS-OCT technology has several types, including time-domain, swept-source, and spectral-domain-based configurations. We performed a literature search on PubMed for articles containing the text “anterior segment OCT,” “ultrasound biomicroscopy,” and “anterior segment imaging” since 2004, with some pertinent references before 2004 included for completeness. This review compares the advantages and disadvantages of AS-OCT and UBM, and summarizes the most recent literature regarding the importance of these devices in glaucoma diagnosis and management. These devices not only aid in visualization of the angle, but also have important postsurgical applications in bleb and tube imaging.     

Clinical use and research applications of Heidelberg retinal angiography and spectral-domain optical coherence tomography – a review

Fluorescein angiography (FA) was discovered by Nowotny and Alvis in the 1960s of the 20th century and has evolved to become the 'Gold standard' for macular diagnostics. Scanning laser imaging technology achieved enhancement of contrast and resolution. The combined Heidelberg retina angiograph (HRA2) adds novel innovative features to established fundus cameras. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure providing comfort and safety for the patient. Enhanced contrast, details and image sharpness image are generated using confocality. For the visualization of the choroid an indocyanine green angiography (ICGA) is the most suitable application. The main indications for ICGA are age-related macular degeneration, choroidal polypoidal vasculopathy and choroidal haemangiomas. Simultaneous digital FA and ICGA images with three-dimensional resolution offer improved diagnosis of retinal and choroidal pathologies. High-speed ICGA dynamic imaging can identify feeder vessels and retinal choroidal anastomoses, ensuring safer treatment of choroidal neovascularization. Autofluorescence imaging and fundus reflectance imaging with blue and infrared light offer new follow-up parameters for retinal diseases. Finally, the real-time optical coherence tomography provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combination of various macular diagnostic tools, such as infrared, blue reflectance, fundus autofluorescence, FA, ICGA and also spectral domain optical coherence tomography, lead to a better understanding and improved knowledge of macular diseases.     

非增生型糖尿病视网膜病变超广角眼底彩色照相与眼底自发荧光图像特征分析

目的　分析非增生型糖尿病视网膜病变（non-proliferative diabetic retinopathy，NPDR）超广角眼底彩色照相与眼底自发荧光（fudus autofluorescence，FAF）的图像特征。方法　使用欧堡全景200激光扫描检眼镜对40例（80眼）NPDR患者进行免散瞳模式下的超广角眼底彩色照相及FAF检查，对所有图像进行分析，得出两种模式下NPDR眼底改变的图像特征及阳性率。结果　超广角眼底彩色照相和FAF的图像质量基本一致，均能反映周边部视网膜的情况。在各种典型的眼底病变中，极其微小的血管瘤以及点片状视网膜出血的显影在FAF上有增强，有助于细微病变的诊断。渗出在FAF上的显影并不明显，分辨率不够。视网膜新鲜性光凝斑在两种模式检查上均显影清晰，陈旧性光凝斑在FAF上易与出血混淆，应谨慎诊断。结论　超广角眼底彩色照相图像清晰，周边部显示好，可以提供直观的视网膜图像；FAF可以观察到组织结构的细微改变及视网膜色素上皮细胞的代谢情况。两种模式相辅相成，能为NPDR的诊断、分期和治疗提供更好的帮助。     

超广角荧光血管造影在视网膜疾病中的应用研究现状

超广角荧光血管造影（UWFA）是近些年眼底成像领域的一项新技术，该技术同时结合了超广角眼底成像技术和荧光造影的血管显影特点，为临床观察周边视网膜血管结构和功能提供了新途径。目前关于UWFA的研究涉及各类眼底疾病。不仅帮助人们更完整地认识了眼底病变的特征，同时还对疾病的治疗规范、监测及预后评估产生了影响，具有很大的临床及科研价值。本文对近年UWFA技术的更新和新的研究成果作一综述。     

眼底疾病影像学检查的合理应用及联合应用

近年来,眼底的影像学诊断技术发展很快,为深入认识和准确诊断眼底病提供了最新的方法.常用的光学影像学方法有彩色相、无赤光相、自发荧光相、荧光素眼底血管造影(FFA)、吲哚青绿血管造影(ICGA)和频域光学相干断层扫描(S-OCT)等.充分掌握眼底影像学的基本知识,合理选择影像学方法,有针对性地进行检查,仔细分析和评价检查结果,对视网膜脉络膜疾病的诊断、鉴别诊断、治疗方案的制定和随访都具有重要的临床意义.     

Imaging in retinal vascular disease: A review

Retinal vascular diseases represent a broad field of ocular pathologies. Retinal imaging is an important tool for diagnosis, prognosis and follow up of retinal vascular diseases. It includes a wide variety of imaging techniques ranging from colour fundus photography and optical coherence tomography to dynamic diagnostic options such as fluorescein angiography, and optical coherence tomography angiography. The newest developments in respective imaging techniques include widefield imaging to assess the retinal periphery, which is of especial interest in retinal vascular diseases. Automatic image analysis and artificial intelligence may support the image analysis and may prove valuable for prognostic purposes. This review provides a broad overview of the imaging techniques that have been used in the past, today and maybe in the future to stage and monitor retinal vascular disease with focus on the main disease entities including diabetic retinopathy, retinal vein occlusion, and retinal artery occlusion.     

Normative data for optical coherence tomography in children: a systematic review

The purpose of this study is to systematically review the reported data of normal optical coherence tomography (OCT) results in the paediatric population. A systematic literature search was performed using the PubMed, Embase, and Web of Science databases, using the keywords “optical coherence tomography”; “normative data” or “healthy eyes”; “children” or “paediatric population”. Studies with at least 50 participants were included, irrespective of the OCT equipment employed. We excluded the OCT angiography studies or the studies investigating the choroidal thickness. Seventy-four studies were included in the final analysis and information on study design, number of participants, demographic characteristics, type of OCT equipment, OCT parameters and results was collected. Due to the high variability of OCT instruments and parameters used, a meta-analysis was not feasible. We report the normative values for the peripapillary retinal nerve fibre layer thickness and the macular retinal thickness for each ETDRS quadrant, as provided by the studies included in the present analysis. We also report the influence of ethnicity, age, gender, eye laterality, ISNT rule, spherical equivalent, and axial length on OCT results.Subject terms: Paediatrics, Medical imaging, Biomarkers     

眼底多模式影像的进展及其现阶段存在的问题

眼底疾病认知的更新离不开眼底多模式影像的快速发展。特别是近年来广角及超广角眼底照相、超广角荧光素眼底血管造影、吲哚青绿血管造影、眼底自身荧光及光相干断层扫描血管成像等检查的应用,让临床医师对周边部视网膜病变的观察更为直接;自适应光学及荧光寿命成像检眼镜的应用,使临床医师在细胞及代谢层次对眼底疾病有了更进一步的认识。多模式影像之间相辅相成,可以从不同角度、不同层次反映疾病的病变特征。同时,眼底影像的数字化及智能化也在快速发展。但是如何正确使用多模式影像,如何正确理解人工智能在眼科影像的应用以及如何从影像中归纳总结,也是每位眼科医生需要思考的问题。     

Capturing the clinical decision-making processes of expert and novice diabetic retinal graders using a ‘think-aloud’ approach

BackgroundDiabetic eye screening programmes have been developed worldwide based on evidence that early detection and treatment of diabetic retinopathy are crucial to preventing sight loss. However, little is known about the decision-making processes and training needs of diabetic retinal graders, particularly in low- and middle-income countries.ObjectivesTo provide data for improving evidence-based diabetic retinopathy training to help novice graders process fundus images more like experts.Subjects/methodsThis is a mixed-methods qualitative study conducted in southern Vietnam and Northern Ireland. Novice diabetic retinal graders in Vietnam (n = 18) and expert graders in Northern Ireland (n = 5) were selected through a purposive sampling technique. Data were collected from 21st February to 3rd September 2019. The interviewer used neutral prompts during think-aloud sessions to encourage participants to verbalise their thought processes while grading fundus images from anonymised patients, followed by semi-structured interviews. Thematic framework analysis was used to identify themes, supported by illustrative quotes from interviews. Mann–Whitney U tests were used to compare graders’ performance.ResultsExpert graders used a more systematic approach when grading images, considered all four images per patient and used available software tools such as red-free filters prior to making a decision on management. The most challenging features for novice graders were intra-retinal microvascular abnormalities and new vessels, which were more accurately identified by experts.ConclusionTaking more time to grade fundus images and adopting a protocol-driven “checklist” approach may help novice graders to function more like experts.Subject terms: Retinal diseases, Medical imaging, Health occupations     

Fluorescein angiographic correlation of focal narrowing of retinal arterioles in glaucoma

BACKGROUND—Recent studies have shown that focal narrowing of retinal arterioles in the parapapillary region occurs in eyes with optic neuropathies such as glaucoma. This study evaluated whether these vessel constrictions detected ophthalmoscopically have an equivalent in angiographic imaging of the fundus.
METHODS—Fluorescein angiograms and colour wide angle fundus photographs of 33 patients with open angle glaucoma and 76 subjects with normal optic nerves were examined for focal narrowing of retinal arterioles. The angiograms had primarily been taken for other reasons such as age related macula degeneration.
RESULTS—All focal narrowings of retinal arterioles detected on fundus photographs showed a localised constriction of vessel filling in the fluorescein angiograms. Degree of vessel narrowing on the fundus photographs and degree of constriction of the fluorescein vessel filling were significantly (p<0.001) correlated with each other.
CONCLUSIONS—Focal narrowing of retinal arterioles in the parapapillary region of eyes with optic neuropathies represents a real stenosis of the vessel lumen and is not due to an ophthalmoscopic artefact.

Keywords: fluorescein angiography; focal vessel constriction; glaucoma; optic disc     

Review of spectral domain-enhanced depth imaging optical coherence tomography of tumors of the retina and retinal pigment epithelium in children and adults

Background:Spectral domain (SD) enhanced depth imaging optical coherence tomography (EDI-OCT) is a useful tool for anatomic, cross-sectional imaging of retinal conditions.Aims:The aim was to identify characteristic patterns of retinal and retinal pigment epithelial tumors on EDI-OCT in children and adults.Results:Using EDI-OCT, retinal tumors such as small retinoblastoma, astrocytic hamartoma, and hemangioblastoma arose abruptly from the retina, immediately adjacent to normal retina. Small exophytic retinoblastoma and retinal hemangioblastoma showed the full-thickness, homogeneous retinal disorganization with surrounding normal retina “draping” over the margins. Retinoblastoma occasionally had intralesional cavities and surrounding subretinal fluid. Hemangioblastoma often had adjacent intraretinal edema and subretinal fluid. Astrocytic hamartoma arose within the nerve fiber layer and sometimes with a “moth-eaten” or cavitary appearance. Retinal pigment epithelial (RPE) lesions such as congenital hypertrophy of RPE appeared flat with shadowing, occasional subretinal cleft, and abrupt photoreceptor loss. Congenital simple hamartoma showed an abrupt elevation from the inner retina with crisp, dark posterior shadowing. Combined hamartoma of the retina/RPE showed vitreoretinal traction causing “sawtooth mini-peak” or gently “maxi-peak” folding of the retina. RPE adenoma often produces remote macular edema or epiretinal membrane and the tumor has an irregular, “rugged” surface with deep shadowing.Conclusions:Enhanced depth imaging optical coherence tomography shows characteristic patterns that are suggestive of certain retinal and RPE tumors.     

正确认识OCT血管成像技术的临床应用价值

OCT血管成像(OCTA)是一项无创、快捷的血流检测技术,目前主要用于视网膜脉络膜的血流成像.与传统的荧光素眼底血管造影(FFA)和吲哚青绿血管造影(ICGA)技术不同,OCTA无需静脉注射造影剂就能够对血流信号进行探测和量化分析,并且能够分层观察和判断视网膜脉络膜的血流改变情况,因此OCTA比传统的眼底血管造影技术提供的血流信息更多、更准确.OCTA作为一项具有革命性突破的新技术,在眼科血管性疾病的诊断及血流改变有关眼病的发病机制探讨方面具有划时代的意义.但是,任何新技术的临床应用都有其限制性和局限性,如OCTA观察的眼底范围并不如FFA和ICGA大,且检查和读图过程中也受到一些因素的影响.充分了解OCTA的成像原理和成像特点有助于眼科医师更好地了解视网膜脉络膜疾病、青光眼和神经眼科疾病的血流改变,并加深对这些疾病发病机制的认识,同时利用该技术对相关眼病进行有效监测和随访.     

周边视网膜变性广角多模影像研究进展

周边视网膜变性是眼科临床常见的病变,不同类型的变性影响不同的视网膜层次,可能对视力造成威胁。尽管现代眼底成像技术被应用于研究其病理生理机制,由于其所处的特殊部位,影像学检查困难,因此发病机制仍不清楚。本文总结了有关周边视网膜变性的多种广角成像技术的影像特征,包括超广角眼底成像、广角频域光学相干断层扫描、光学相干断层扫描血管成像、荧光素眼底血管造影等,及其发病机制或病理特点的新观点,为临床诊疗提供新的思路。由于样本量非常少,且缺乏前瞻性、长期的多模态影像的观察研究,因而目前仍无法全面评价不同类型病变的进展性及危险性。期望在更广的范围内应用多模态广角成像技术对此类疾病进行研究,指导临床干预决策。     

Diagnosis of Choroidal Melanoma in Dense Asteroid Hyalosis

Purpose: To demonstrate the utility of Optos ultra-wide field imaging in the diagnosis and management of choroidal melanoma in the setting of asteroid hyalosis. Design: Observational case report. Method: A 52-year-old female was referred for evaluation of floaters, photopsias, and blurry vision in the right eye. Clinical examination revealed dense asteroid hyalosis obscuring the fundus, and a limited view of a pigmented choroidal lesion in the nasal periphery. Optos ultra-wide field fluorescein angiography and ultrasonography facilitated the diagnosis of a choroidal melanoma. Results: The patient underwent Iodine-125 brachytherapy for local tumor control and excellent tumor response was confirmed with serial follow-up Optos imaging and ultrasonography. Conclusion: Ultra-wide field fundus fluorescein angiography facilitated the diagnosis of a choroidal melanoma, which was obscured by dense asteroid hyalosis, allowing for local tumor control with brachytherapy. Optos wide-field imaging may be a valuable tool for detecting potentially life-threatening lesions in the setting of asteroid hyalosis.     

超广角荧光素眼底血管造影在视网膜分支静脉阻塞诊治中的应用

目的　评价超广角荧光素眼底血管造影（fundus fluorescein angiography,FFA）在视网膜分支静脉阻塞诊断、治疗中的指导价值。方法　回顾分析40例（41眼）视网膜分支静脉阻塞确诊患者的传统FFA和超广角FFA资料。所有患者造影检查的早中期均行传统FFA,晚期均行欧堡超广角FFA。分析比较2种检查的视网膜可视范围、视网膜无灌注区面积、视网膜所需激光面积。结果　与传统FFA图像比较,超广角FFA检查图像所显示的视网膜可视面积以及视网膜无灌注区面积、所需激光面积分别是前者的2.03倍、1.57倍、1.96倍（均为P<0.01）。未行激光治疗的27眼中22眼有无灌注区,其中同时合并黄斑水肿者15眼,这15眼中无灌注区在赤道部以前者14眼;已行激光治疗的14眼中9眼存在黄斑水肿的表现,9眼中7眼合并无灌注区,其中6眼的无灌注区在赤道部以前。结论　超广角FFA使可观测病变检查范围扩大到远周边,对视网膜分支静脉阻塞的诊断和治疗提供更多帮助。     

Novel approach towards colour imaging using a scanning laser ophthalmoscope

AIMS—Conventional fundus imaging using a fundus camera produces colour fundus pictures. The scanning laser ophthalmoscope (SLO) has the advantages of lower levels of light exposure, improved contrast, and direct digital imaging but until now has produced monochromatic images as a laser of single wavelength is used. True representation of the fundus is possible by combining images taken using blue, green, and red lasers.
METHODS—A custom built SLO was used to capture blue, green, and red fundus images from suitable volunteers and patients with fundus disease. Images were corrected for eye movement and combined to form a colour image. Colour fundus photographs were taken using a fundus camera for comparison with the SLO image.
RESULTS—The background fundus and retinal vasculature had similar appearances with the two imaging modalities. Internal limiting membrane reflections were prominent with the SLO. Identification of new vessels in the diabetic fundus was easier with the SLO than the colour fundus photographs.
CONCLUSION—A colour SLO offers all the advantages of the present monochromatic imaging system with the added advantage of true colour representation of the fundus.

Keywords: scanning laser ophthalmoscope; fundus imaging; digital colour fundus images     

急性视网膜坏死综合征的眼底血管造影

目的观察急性视网膜坏死综合征（ARNS）的荧光素眼底血管造影（FFA）和吲哚青绿血管造影（ICGA）图像特征及在临床诊断中的应用价值。方法回顾性分析20例临床诊断为ARNS的患者28只患眼的眼底、FFA和ICGA检查资料。结果FFA图像中，视盘边界不清、晚期强荧光24只眼，占85.71%；周边部病灶区视网膜动静脉血管广泛闭塞23只眼，占82.14%，部分仅见闭塞的血管暗影，检眼镜检查所见的部分呈白线状的血管仍有荧光素通过； 病灶区与较正常视网膜交界处较多荧光素渗漏点者22只眼，占78.57%；视网膜脱离20只眼，占71.42%，其中9只眼未发现视网膜裂孔，占视网膜脱离者的45.00% ；8只眼黄斑囊样水肿，占28.57%。ICGA图像中，视盘强荧光8只眼，占28.57%，其中有5只眼晚期视盘内见颗粒状染色；周边部病灶区脉络膜血管模糊不清者20只眼，占71.42%；病灶区脉络膜散在片状弱荧光区19只眼，占67.85%；ICGA晚期图像中，视网膜血管内栓子及视网膜血管闭塞区清晰可见。结论ARNS 的FFA表现主要是视盘强荧光和视网膜血管闭塞；ICGA主要表现是病灶区脉络膜血管模糊不清及散在片状弱荧光区。两种检查联合使用，可进一步了解病变损害的程度以及脉络膜与视网膜之间的相互关系，对ARNS的诊断有重要的参考价值。(中华眼底病杂志,2005,21:100-102)     

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.     

视网膜大动脉瘤的多模式影像学特征及并发症观察

目的　观察视网膜大动脉瘤的多模式影像学特征及并发症。方法　回顾性分析2014年1月至2018年11月在我院确诊为视网膜大动脉瘤的临床病例资料。所有患者均行常规的眼部检查和眼底影像学检查,包括眼底彩照、频域光学相干断层扫描（spectral-domain optical coherence tomography,SD-OCT）、荧光素眼底血管造影（fundus fluorescein angiography,FFA）和（或）吲哚菁绿血管造影（indocyanine green angiography,ICGA）检查。分析其眼底影像学特征,观察并发症情况。结果　39例患者纳入本研究,均为单眼发病。男7例（17.95%）,女32例（82.05%）,年龄53~86(71.33±9.06)岁。有高血压病史者30例（76.92%）。除1例为双瘤体外,其余均为单瘤体。所有患者均完成了眼底彩色照相和SD-OCT检查,38例完成FFA检查,8例完成ICGA检查。各项检查发现大动脉瘤体的情况:眼底彩色照相32例（82.05%）,SD-OCT检查31例（79.49%）,FFA检查32例（84.21%）,ICGA检查8例（100.00%）。39例患者中,9例并发了不同程度的玻璃体积血,1例并发视网膜分支动脉阻塞,1例并发视网膜分支动脉阻塞和分支静脉阻塞。结论　眼底彩色照相、SD-OCT检查联合FFA检查可对大部分视网膜大动脉瘤进行明确诊断,ICGA检查可作为一项重要的补充检查手段。视网膜大动脉瘤可合并视网膜分支动脉或分支静脉阻塞,应引起临床重视。