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Author(s):  
Ruy Felippe Brito Gonçalves Missaka ◽  
Mauro Goldbaum ◽  
Cleide Guimarães Machado ◽  
Emmett T. Cunningham ◽  
Fernanda Maria Silveira Souto ◽  
...  

Abstract Background The tomographic finding, which has been called the "fingerprint sign" in en face reconstructions, seems to be the result of a variety of processes that cause distension of the outer plexiform layer (OPL) and the Henle fiber layer (HFL). The aim of this paper is to describe the appearance of concentric rings at the OPL/HFL interface visualized using en face reconstructions of cross-sectional optical coherence tomography images of patients with Vogt-Koyanagi-Harada disease. Methods Retrospective analysis of images of six eyes of three patients obtained by cross-sectional OCT imaging and en face reconstruction at the level of the OPL/HFL interface. Results All eyes presented with a dentate or saw-tooth pattern of the OPL/HFL interface on cross-sectional OCT with corresponding concentric rings on en face OCT reconstruction, consistent with the recently published “fingerprint sign”. Initial OPL/HFL interface changes were observed between the first and fourth months after treatment and resolution of VKHD associated serous retinal detachments. These OPL/HFL interface changes have persisted for many years following the resolution of the active inflammation. Conclusions Changes in the OPL/HFL interface can be identified following successful treatment of VKHD. These included both a dentate or saw-tooth pattern on cross-sectional imaging and concentric rings or the “fingerprint sign” on en face reconstructions. These changes persisted for many years despite disease quiescence.


2022 ◽  
Vol 11 (2) ◽  
pp. 329
Author(s):  
Marta P. Wiącek ◽  
Monika Kuśmierz-Wojtasik ◽  
Bogna Kowalska ◽  
Anna Machalińska

Background: Both pterygium ingrowth and excision determine alterations in corneal topography. The aim of this study was to evaluate the influence of pterygium removal combined with conjunctival autografts in addition to the use of human fibrin tissue glue on changes in corneal parameters as measured by 3-D swept-source anterior segment optical coherence tomography (AS-OCT) imaging. Methods: Sixteen eyes (16 patients) with pterygium that qualified for surgical treatment were enrolled in this study. Eye examination, slit lamp, and 3-D AS-OCT (CASIA 2) assessment were performed before the surgery and 7 days, 1 month, and 6 months after pterygium excision. Topographic parameters of both anterior and posterior surfaces of the cornea were analysed at each follow-up visit. Results: The gradual decrease in total astigmatism power from preoperative median 2.75 (6.15) D to 1.2 (1.1) D at 6-month follow-up (p = 0.034) was noted from the day 7 visit. Values were strongly influenced by variations of anterior cornea astigmatism. In contrast, a gradual total HOA reduction at the 1-month (from median 0.79 (1.3) D to 0.44 (0.27) D; p = 0.038) and at 6-month visits (0.25 (0.09); p = 0.001) was observed. Similarly, values were strongly influenced by variations of the anterior. Additionally, total average keratometry values increased from preoperative 44.05 (2.25) D to 44.6 (1.9) (p = 0.043) 1 month after the surgery. Conclusions: Significant steepening of the anterior cornea and a reduction in both astigmatism and HOA were observed after pterygium excision. The anterior corneal surface was an essential component of the total postoperative corneal topography values. Three-dimensional swept-source AS-OCT imaging seems to be a valuable tool for monitoring both the progression of the disease and postoperative effects in pterygium eyes.


2021 ◽  
Author(s):  
Robnier Reyes Perez

This thesis presents an imaging tool consisting of an Optical Coherence Tomography (OCT) imaging system mounted on a collaborative robotic arm to enable axial motion compensation. Optical Coherence Tomography is a subsurface, high-resolution imaging modality used in neuroimaging to differentiate between pathological and non-pathological tissue. The motivation behind this project is to bring Optical Coherence Tomography to the operating room for neuroimaging to help with cancerous tissue differentiation and maximize the extent of tumor resection. However, neurosurgeons have expressed concern with respect to intracranial pressure (ICP) pulsation displacing the brain far off the optic axis of the imaging system so as to not be visible. The collaborative robotic arm compensates for sample motion along the optic axis using a Proportional controller to track the position of the peak intensity of the sample’s intensity profile, which generally corresponds to the sample surface. Collaborative robots have changed the robot industry paradigm becoming increasingly functional and safer than the previous generations of robotic arms. We present an OCT robot end-effector to test the feasibility of performing OCT imaging with the collaborative robot.


2021 ◽  
Author(s):  
Robnier Reyes Perez

This thesis presents an imaging tool consisting of an Optical Coherence Tomography (OCT) imaging system mounted on a collaborative robotic arm to enable axial motion compensation. Optical Coherence Tomography is a subsurface, high-resolution imaging modality used in neuroimaging to differentiate between pathological and non-pathological tissue. The motivation behind this project is to bring Optical Coherence Tomography to the operating room for neuroimaging to help with cancerous tissue differentiation and maximize the extent of tumor resection. However, neurosurgeons have expressed concern with respect to intracranial pressure (ICP) pulsation displacing the brain far off the optic axis of the imaging system so as to not be visible. The collaborative robotic arm compensates for sample motion along the optic axis using a Proportional controller to track the position of the peak intensity of the sample’s intensity profile, which generally corresponds to the sample surface. Collaborative robots have changed the robot industry paradigm becoming increasingly functional and safer than the previous generations of robotic arms. We present an OCT robot end-effector to test the feasibility of performing OCT imaging with the collaborative robot.


Author(s):  
Camilla Chello ◽  
Stefania Caramaschi ◽  
Alberto Sticchi ◽  
Andrea Naselli ◽  
Claudia Pezzini ◽  
...  

2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Yasser Elkholy ◽  
Ayman Nassar ◽  
Zeinab Elsanabary ◽  
Ahmed Daifalla ◽  
Elham Gad

2021 ◽  
Vol 15 ◽  
Author(s):  
Qingwen Yang ◽  
Hongquan Guo ◽  
Xuan Shi ◽  
Xiaohui Xu ◽  
Mingming Zha ◽  
...  

Introduction: Symptomatic carotid disease conveys a high risk of recurrent stroke. Plaque morphology and specific plaque characteristics are associated with the risk of stroke. This study aimed to evaluate the detailed plaque features by optical coherence tomography (OCT) and develop a simple scale combining clinical indicators, digital subtraction angiography (DSA), and OCT imaging markers to identify symptomatic carotid plaque.Methods: Carotid plaques from consecutive patients who underwent carotid OCT imaging between June 2017 and June 2021 were evaluated. Clinical characteristics, DSA, and OCT data were compared between the symptomatic and asymptomatic groups. Logistic regression was performed to identify the factors associated with symptomatic carotid plaque and to develop a scale. The area under the receiver operating characteristic curve (AUC) was used to evaluate the performance of the scale.Results: A total of 90 carotid plaques from 90 patients were included (symptomatic 35.6%, asymptomatic 64.4%). Three main factors were found to be associated with symptomatic carotid plaque: high-density lipoprotein cholesterol (HDL-C) <0.925 mmol/L (OR, 4.708; 95% CI, 1.640 to 13.517; P = 0.004), irregular plaque (OR, 4.017; 95% CI, 1.250 to 12.910; P = 0.020), and white thrombus (OR, 4.594; 95% CI, 1.141 to 18.487; P = 0.032). The corresponding score of three items produced a scale with good discrimination (AUC, 0.768; 95% CI, 0.665 to 0.871). The optimal cutoff value of the scale was 1.5 points with 59.4% sensitivity and 84.5% specificity.Conclusion: The three-item scale comprising HDL-C <0.925 mmol/L, angiographical irregular plaque, and white thrombus detected by OCT may provide information to identify symptomatic carotid plaque. Further large-scale studies are required to validate whether the symptomatic carotid plaque scale is clinically valuable in recognizing carotid atherosclerosis in the early stages.


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2313
Author(s):  
Mohamed Elsharkawy ◽  
Mostafa Elrazzaz ◽  
Mohammed Ghazal ◽  
Marah Alhalabi ◽  
Ahmed Soliman ◽  
...  

In developed countries, age-related macular degeneration (AMD), a retinal disease, is the main cause of vision loss in the elderly. Optical Coherence Tomography (OCT) is currently the gold standard for assessing individuals for initial AMD diagnosis. In this paper, we look at how OCT imaging can be used to diagnose AMD. Our main aim is to examine and compare automated computer-aided diagnostic (CAD) systems for diagnosing and grading of AMD. We provide a brief summary, outlining the main aspects of performance assessment and providing a basis for current research in AMD diagnosis. As a result, the only viable alternative is to prevent AMD and stop both this devastating eye condition and unwanted visual impairment. On the other hand, the grading of AMD is very important in order to detect early AMD and prevent patients from reaching advanced AMD disease. In light of this, we explore the remaining issues with automated systems for AMD detection based on OCT imaging, as well as potential directions for diagnosis and monitoring systems based on OCT imaging and telemedicine applications.


2021 ◽  
Vol 8 ◽  
Author(s):  
Li Dong ◽  
Yi Fan Li ◽  
Xue Jiang ◽  
Yin Jun Lan ◽  
Lei Shao ◽  
...  

Purpose: To evaluate the feasibility of in-vivo imaging of the retina and choroid using spectral domain optical coherence tomography (OCT) in guinea pigs.Methods: The study included 19 pigmented guinea pigs (age: 3–4 weeks) which underwent sonographic axial length measurements and OCT imaging. At study end, the animals were sacrificed and histomorphometric examinations of the retina and choroid were performed. We assessed the reproducibility of the OCT measurements and compared in-vivo measurements to histomorphometric data.Results: The mean thickness of the retina and choroid near the optic nerve head was 175.6 ± 25.8 and 63.4 ± 16.5 μm, respectively, and mean Bruch's membrane opening (BMO) diameter was 831 ± 121 μm. The intra-observer comparison of measurements of retinal thickness (intraclass correlation coefficient (ICC) = 0.92, 95% CI: 0.86–0.96; P < 0.001), choroidal thickness (ICC = 0.92, 95% CI: 0.86–0.96; P < 0.001), and BMO diameter (ICC = 0.92, 95% CI: 0.86–0.96; P < 0.001) showed a high correlation. A high agreement was present also for the inter-observer reproducibility of the measurements of retinal thickness (Pearson correlation coefficient (R) = 0.98; P < 0.001), choroidal thickness (R = 0.96; P < 0.001), and BMO diameter (R = 0.98; P < 0.001). The Bland-Altman plots showed that 2.6% (1/38), 5.3% (2/38), and 7.9% (3/38) of the measurement points of retinal thickness, choroidal thickness and BMO diameter, respectively, were located outside of the 95% limits of agreement. The OCT-based thickness measurements of retina and choroid were significantly higher than those measured by histomorphometry (both P-values <0.01).Conclusion: OCT-based in-vivo morphometric imaging of the retina and choroid in guinea pigs is feasible with an acceptable intra-observer repeatability and inter-observer reproducibility.


2021 ◽  
Vol 23 (Supplement_G) ◽  
Author(s):  
Alfredo Ricchiuto ◽  
Rocco Vergallo ◽  
Marco Lombardi ◽  
Alessandro Maino ◽  
Emiliano Bianchini ◽  
...  

Abstract A 64-year-old man, prior smoker, with a history of paroxysmal atrial fibrillation was referred to our hospital due to worsening dyspnoea, progressively worsening angina, and a positive stress EKG testing. Coronary angiography (CAG) showed an angiographically intermediate stenosis of the mid left anterior descending (LAD) artery and a focal, complex lesion of the distal right coronary artery (RCA) (Figure 1A and B, red arrow). Treatment of the LAD stenosis was deferred based on a negative fractional flow reserve value (i.e. 0.85). Optical coherence tomography (OCT) imaging (ILUMIEN OPTIS, Abbott Vascular, Santa Clara, CA) was performed to better characterize the RCA lesion, which disclosed a ruptured thin-cap fibroatheroma (TCFA) with a large ‘empty’ cavity (Figure 1C–G, red arrows) and overlying ‘layered’ tissue (Figure 1H, white arrowheads). Based on these OCT findings, suggestive of initial plaque healing, and on a large residual lumen dimension (i.e. minimum lumen area, MLA, at the rupture site: 7.7 mm2), this lesion was not treated with percutaneous coronary intervention. The patient was discharged on aspirin, edoxaban, metoprolol, rosuvastatin, and ezetimibe, and remained clinically stable for more than 1 year. Due to angina recurrence, a new CAG was performed 18 months after the first admission, revealing a progression of the mid LAD stenosis that was treated with a 2.5/28 mm drug-eluting stent, and an improvement of the RCA lesion angiographic appearance (smooth contour) (Figure 1A′–B′). RCA OCT imaging was repeated demonstrating a complete healing of the large rupture cavity with all the hallmarks of the reparative process (Figure 1C′–H′): (1) re-established fibrous cap integrity and smooth vessel lumen profile; (2) thickening of the fibrous cap and reduction of lipid burden (i.e., transformation of TCFA into thick-cap fibroatheroma, ThCFA); (3) replacement of the ‘empty’ cavity with new ‘granulation tissue’; (4) initial calcification of the plaque; (5) heterogeneous signal-rich layers with distinct optical-signal intensity (layered, ‘onion-like’ pattern); and (6) mild lumen narrowing (MLA at the rupture site: 6.9 mm2).


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