scholarly journals Optical coherence tomography angiography findings in diabetic macular edema

2021 ◽  
Vol 4 ◽  
pp. 3
Author(s):  
Rene Alfredo Cano-Hidalgo ◽  
Tatiana Urrea-Victoria

Optical coherence tomography angiography (OCT-A) was developed as an extension of OCT imaging. This technology allowed for the visualization of retinal microvasculature in vivo, without the need for contrast dye, provides depth-resolved images of blood flow in the retina and choroid with levels of detail far exceeding that obtained with older forms of imaging. OCT-A has been recently used for noninvasive evaluation of macular and peripapillary capillary network alterations in diabetic retinopathy, and the ability to clearly visualize microvascular changes has allowed for a better assessment of the microvascular retinal alterations, retinal ischemia, and neovascularization in diabetic macular edema (DME) patient. The present paper aims to review the most recent information about the findings for diagnostic interpretation in DME using OCT angiography.

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ayman G. Elnahry ◽  
Gehad A. Elnahry

Background. Diabetic macular edema (DME) is a major cause of vision loss in diabetics that is currently mainly treated by antivascular endothelial growth factor (VEGF) agents. The effect of these agents on macular perfusion (MP) is a current concern. Optical coherence tomography angiography (OCTA) is an imaging modality that allows noninvasive high-resolution retinal microvasculature imaging. Several recent studies evaluated the effect of anti-VEGF agents on the MP of DME patients using OCTA. Our aim is to provide a systematic review of these studies. Methods. Multiple databases were searched including PubMed, Ovid Medline, EMBASE, and Google Scholar for relevant studies published between January 2016 and November 2020 which were included in this review. Studies were compared regarding their design, the number of included patients, the machine and scanning protocol used, the inclusion and exclusion criteria, the number of injections given, the type of anti-VEGF agent used, the outcome measures assessed, and the effect of injections on different MP parameters. Results. A total of 16 studies were included. The studies assessed various OCTA parameters that define MP including the foveal avascular zone area and superficial and deep vascular density and yielded conflicting results. Seven studies showed stable or improved MP following treatment, while 7 studies showed worsening MP following treatment, and 2 studies showed inconclusive results. This could have been due to differences in study design, inclusion criteria, type of anti-VEGF agents used, treatment duration, and methods of image analysis and vascular density quantification. All identified studies were noncomparative case series, and 14 of them (87.5%) used the RTVue XR Avanti OCTA machine. Only one study compared OCTA to fluorescein angiography findings. Conclusion. Analysis of MP changes following VEGF inhibition for DME could benefit from a unified scanning protocol and analysis approach that uses similar study designs to eliminate potential sources of bias. This may provide more definitive conclusions regarding the effect of treatment on MP.


Author(s):  
Eugenia Custo Greig ◽  
Jay S. Duker ◽  
Nadia K. Waheed

Abstract Background Optical coherence tomography angiography (OCTA) can image the retinal vasculature in vivo, without the need for contrast dye. This technology has been commercially available since 2014, however, much of its use has been limited to the research setting. Over time, more clinical practices have adopted OCTA imaging. While countless publications detail OCTA’s use for the study of retinal microvasculature, few studies outline OCTA’s clinical utility. Body This review provides an overview of OCTA imaging and details tips for successful interpretation. The review begins with a summary of OCTA technology and artifacts that arise from image acquisition. New methods and best practices to prevent image artifacts are discussed. OCTA has the unique ability among retinovascular imaging modalities to individually visualize each retinal plexus. Slabs offered in standard OCTA devices are reviewed, and clinical uses for each slab are outlined. Lastly, the use of OCTA for the clinical interpretation of retinal pathology, such as diabetic retinopathy and age-related macular degeneration, is discussed. Conclusion OCTA is evolving from a scientific tool to a clinical imaging device. This review provides a toolkit for successful image interpretation in a clinical setting.


2020 ◽  
Vol 12 ◽  
pp. 251584142094793
Author(s):  
Khalil Ghasemi Falavarjani ◽  
Reza Mirshahi ◽  
Shahriar Ghasemizadeh ◽  
Mahsa Sardarinia

Aim: To determine the minimum number of optical coherence tomography B-scan corrections required to provide acceptable vessel density measurements on optical coherence tomography angiography images in eyes with diabetic macular edema. Methods: In this prospective, noninterventional case series, the optical coherence tomography angiography images of eyes with center-involving diabetic macular edema were assessed. Optical coherence tomography angiography imaging was performed using RTVue Avanti spectral-domain optical coherence tomography system with the AngioVue software (V.2017.1.0.151; Optovue, Fremont, CA, USA). Segmentation error was recorded and manually corrected in the inner retinal layers in the central foveal, 100th and 200th optical coherence tomography B-scans. The segmentation error correction was then continued until all optical coherence tomography B-scans in whole en face image were corrected. At each step, the manual correction of each optical coherence tomography B-scan was propagated to whole image. The vessel density and retinal thickness were recorded at baseline and after each optical coherence tomography B-scan correction. Results: A total of 36 eyes of 26 patients were included. To achieve full segmentation error correction in whole en face image, an average of 1.72 ± 1.81 and 5.57 ± 3.87 B-scans was corrected in inner plexiform layer and outer plexiform layer, respectively. The change in the vessel density measurements after complete segmentation error correction was statistically significant after inner plexiform layer correction. However, no statistically significant change in vessel density was found after manual correction of the outer plexiform layer. The vessel density measurements were statistically significantly different after single central foveal B-scan correction of inner plexiform layer compared with the baseline measurements ( p = 0.03); however, it remained unchanged after further segmentation corrections of inner plexiform layer. Conclusion: Multiple optical coherence tomography B-scans should be manually corrected to address segmentation error in whole images of en face optical coherence tomography angiography in eyes with diabetic macular edema. Correction of central foveal B-scan provides the most significant change in vessel density measurements in eyes with diabetic macular edema.


Diabetic retinopathy is an important public health issue as its prevalence has been increasing every year. It is one of the major causes of visual loss which can be preventable with early diagnosis and appropriate treatment. The fundus examination must be done in detail using mydriatics, and digital images must be recorded in all diabetic patients with special emphasis on the disease type (type I and type II), duration, and prognosis. Fluorescein angiography (FA) is a gold standard invasive retinal imaging technique for the diagnosis, monitoring, and evaluating the response of the treatment in diabetic patients, but FA has limitations due to possible side effects. Optical coherence tomography angiography (OCTA) is a recent, non-invasive, dye-free imaging technique that can be used in every visit. It has the capability to image all retinal and choroidal vascular layers (segmentation) and quantify macular ischemia in a short period of time which is beneficial for the patient, and the ophthalmologist. The aim of this review is to address the findings, advantages, and disadvantages of FA and OCTA in patients with diabetic retinopathy and diabetic macular edema.


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