scholarly journals Spectral-Domain Optical Coherence Tomography for Macular Edema

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Emmerson Badaró ◽  
Eduardo Novais ◽  
Larissa Maria Prodocimo ◽  
Juliana M. Ferraz Sallum
Keyword(s):  
Optical Coherence Tomography ◽  
Clinical Practice ◽  
Image Resolution ◽  
Spectral Domain ◽  
Retinal Diseases ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Spectral Domain Oct ◽  
Acquisition Speed

Optical coherence tomography (OCT) is a rapid noncontact method that allows in vivo imaging of the retina and it has become an important component in clinical practice. OCT is a useful ancillary tool for assessing retinal diseases because of its ability to provide cross-sectional retinal images and quantitatively analyze retinal morphology. The introduction of spectral-domain OCT provided major improvements in image acquisition speed and image resolution. Future studies will address how these major technologic advances will impact the use of OCT in research and clinical practice.

scholarly journals Retinal Damage in Multiple Sclerosis Disease Subtypes Measured by High-Resolution Optical Coherence Tomography

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Timm Oberwahrenbrock ◽  
Sven Schippling ◽  
Marius Ringelstein ◽  
Falko Kaufhold ◽  
Hanna Zimmermann ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Neuritis ◽  
Large Scale ◽  
Retinal Nerve Fibre Layer ◽  
Spectral Domain ◽  
Healthy Controls ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Spectral Domain Oct ◽  
Rnfl Thickness

Background.Optical coherence tomography (OCT) has facilitated characterisation of retinal alterations in MS patients. Only scarce and in part conflicting data exists on different MS subtypes.Objective.To analyse patterns of retinal changes in different subtypes of MS with latest spectral-domain technology.Methods.In a three-centre cross-sectional study 414 MS patients and 94 healthy controls underwent spectral-domain OCT examination.Results.Eyes of MS patients without a previous optic neuritis showed a significant reduction of both retinal nerve fibre layer (RNFL) thickness and total macular volume (TMV) compared to healthy controls independent of the MS subtype (P<0.001for all subtypes). RNFL thickness was lower in secondary progressive MS (SPMS) eyes compared to relapsing-remitting MS (RRMS) eyes (P=0.007), and TMV was reduced in SPMS and primary progressive MS (PPMS) eyes compared to RRMS eyes (SPMS:P=0.039, PPMS:P=0.005). Independent of the subtype a more pronounced RNFL thinning and TMV reduction were found in eyes with a previous optic neuritis compared to unaffected eyes.Conclusion.Analysis of this large-scale cross-sectional dataset of MS patients studied with spectral-domain OCT confirmed and allows to generalize previous findings. Furthermore it carves out distinct patterns in different MS subtypes.

scholarly journals Optical Coherence Tomography in the Diagnosis and Monitoring of Retinal Diseases

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Simona-Delia Ţălu
Keyword(s):  
Optical Coherence Tomography ◽  
Adaptive Optics ◽  
Motion Artifacts ◽  
Enhanced Depth Imaging ◽  
Retinal Diseases ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Sd Oct

Optical coherence tomography (OCT) allows the visualization of the retinal microarchitecture as cross-sectional or tomographic volumetric data. The usefulness of OCT in the management of various retinal diseases is validated by the possibility to allow early diagnosis and to help in the decision-making process. OCT is applied by two main methods: time domain (TD-OCT) and spectral domain (SD-OCT). The advantages of SD-OCT over TD-OCT are significant improvement of the image axial resolution, decreased acquisition times, reduction of motion artifacts, increased area of retinal sampling, and the possibility to create topographic maps by the three-dimensional evaluation of tissues. OCT is the most precise method to measure the central macular thickness (which is the most important practical parameter) in vivo. It has been demonstrated that there are differences in the retinal thickness measurements between OCT models, explained by the higher axial and transverse resolutions of the newer devices. Further research has led to significant improvements in OCT technology represented by ultrahigh resolution OCT (UHR-OCT), swept source OCT (SS-OCT), enhanced depth imaging OCT (EDI-OCT), and adaptive optics. Technological progress in OCT imaging offered new perspectives for better understanding the retinal diseases, opening new avenues for the fundamental and clinical research. This is a review of the data in the literature concerning the evolution of OCT technology in the field of retinal imaging.

Time domain and spectral domain optical coherence tomography in multiple sclerosis: a comparative cross-sectional study

2010 ◽  
Vol 16 (7) ◽  
pp. 893-896 ◽  
Author(s):  
Markus Bock ◽  
Alexander Ulrich Brandt ◽  
Jan Dörr ◽  
Caspar F Pfueller ◽  
Stephanie Ohlraun ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Optical Coherence Tomography ◽  
Time Domain ◽  
Conventional Technique ◽  
Retinal Nerve Fibre Layer ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Multiple Sclerosis Patients

Conventional time domain optical coherence tomography has been established for the in vivo assessment of retinal axonal loss in multiple sclerosis. The innovative spectral domain imaging is superior to the conventional technique with respect to data acquisition speed, resolution and reproducibility. However, until now comparability of the two techniques has not been investigated in multiple sclerosis. In this study involving 55 multiple sclerosis patients, data obtained using both techniques (Stratus time domain optical coherence tomography and Cirrus spectral domain optical coherence tomography, Carl Zeiss Meditec) showed an excellent correlation (Pearson’s r = 0.926, p < 0.001). However, owing to considerable differences in absolute retinal nerve fibre layer measurements (mean ± standard deviation 8.1 µm ± 6.2, range -12 to 23 µm), results from the two devices are not interchangeable.

scholarly journals Comparison of swept-source versus spectral-domain optical coherence tomography angiography for detection of macular neovascularization

2021 ◽  
Author(s):  
Anna Lentzsch ◽  
Laura Schöllhorn ◽  
Christel Schnorr ◽  
Robert Siggel ◽  
Sandra Liakopoulos
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
En Face ◽  
Increased Sensitivity ◽  
Sensitivity Specificity ◽  
Subretinal Hyperreflective Material

Abstract Purpose To compare swept-source (SS) versus spectral-domain (SD) optical coherence tomography angiography (OCTA) for the detection of macular neovascularization (MNV). Methods In this prospective cohort study, 72 eyes of 54 patients with subretinal hyperreflective material (SHRM) and/or pigment epithelial detachment (PED) on OCT possibly corresponding to MNV in at least one eye were included. OCTA scans were acquired using two devices, the PLEX Elite 9000 SS-OCTA and the Spectralis SD-OCTA. Fluorescein angiography (FA) was used as reference. Two graders independently evaluated en face OCTA images using a preset slab as well as a manually modified slab, followed by a combination of en face and cross-sectional OCTA. Results Sensitivity (specificity) for the automated slabs was 51.7% (93.0%) for SS-OCTA versus 58.6% (95.3%) for SD-OCTA. Manual modification of segmentation increased sensitivity to 79.3% for SS-OCTA but not for SD-OCTA (58.6%). The combination of en face OCTA with cross-sectional OCTA reached highest sensitivity values (SS-OCTA: 82.8%, SD-OCTA: 86.2%), and lowest number of cases with discrepancies between SS-OCTA and SD-OCTA (4.2%). Fleiss kappa as measure of concordance between FA, SS-OCTA, and SD-OCTA was 0.56 for the automated slabs, 0.60 for the manual slabs, and 0.73 (good agreement) for the combination of en face OCTA with cross-sectional OCTA. Concordance to FA was moderate for the automated slabs and good for manual slabs and combination with cross-sectional OCTA of both devices. Conclusion Both devices reached comparable results regarding the detection of MNV on OCTA. Sensitivity for MNV detection and agreement between devices was best when evaluating a combination of en face and cross-sectional OCTA.

scholarly journals Optimization of X-ray Investigations in Dentistry Using Optical Coherence Tomography

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4554
Author(s):  
Ralph-Alexandru Erdelyi ◽  
Virgil-Florin Duma ◽  
Cosmin Sinescu ◽  
George Mihai Dobre ◽  
Adrian Bradu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Radiation Dose ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Optical Coherence ◽  
X Rays ◽  
High Quality ◽  
X Ray

The most common imaging technique for dental diagnoses and treatment monitoring is X-ray imaging, which evolved from the first intraoral radiographs to high-quality three-dimensional (3D) Cone Beam Computed Tomography (CBCT). Other imaging techniques have shown potential, such as Optical Coherence Tomography (OCT). We have recently reported on the boundaries of these two types of techniques, regarding. the dental fields where each one is more appropriate or where they should be both used. The aim of the present study is to explore the unique capabilities of the OCT technique to optimize X-ray units imaging (i.e., in terms of image resolution, radiation dose, or contrast). Two types of commercially available and widely used X-ray units are considered. To adjust their parameters, a protocol is developed to employ OCT images of dental conditions that are documented on high (i.e., less than 10 μm) resolution OCT images (both B-scans/cross sections and 3D reconstructions) but are hardly identified on the 200 to 75 μm resolution panoramic or CBCT radiographs. The optimized calibration of the X-ray unit includes choosing appropriate values for the anode voltage and current intensity of the X-ray tube, as well as the patient’s positioning, in order to reach the highest possible X-rays resolution at a radiation dose that is safe for the patient. The optimization protocol is developed in vitro on OCT images of extracted teeth and is further applied in vivo for each type of dental investigation. Optimized radiographic results are compared with un-optimized previously performed radiographs. Also, we show that OCT can permit a rigorous comparison between two (types of) X-ray units. In conclusion, high-quality dental images are possible using low radiation doses if an optimized protocol, developed using OCT, is applied for each type of dental investigation. Also, there are situations when the X-ray technology has drawbacks for dental diagnosis or treatment assessment. In such situations, OCT proves capable to provide qualitative images.

scholarly journals Design and Implementation Guidelines for a Modular Spectral-Domain Optical Coherence Tomography Scanner

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Farid Atry ◽  
Israel Jacob De La Rosa ◽  
Kevin R. Rarick ◽  
Ramin Pashaie
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Optical Design ◽  
Spectral Domain ◽  
Design Parameters ◽  
Optical Coherence ◽  
Custom Made ◽  
Essential Knowledge ◽  
Sd Oct

In the past decades, spectral-domain optical coherence tomography (SD-OCT) has transformed into a widely popular imaging technology which is used in many research and clinical applications. Despite such fast growth in the field, the technology has not been readily accessible to many research laboratories either due to the cost or inflexibility of the commercially available systems or due to the lack of essential knowledge in the field of optics to develop custom-made scanners that suit specific applications. This paper aims to provide a detailed discussion on the design and development process of a typical SD-OCT scanner. The effects of multiple design parameters, for the main optical and optomechanical components, on the overall performance of the imaging system are analyzed and discussions are provided to serve as a guideline for the development of a custom SD-OCT system. While this article can be generalized for different applications, we will demonstrate the design of a SD-OCT system and representative results for in vivo brain imaging. We explain procedures to measure the axial and transversal resolutions and field of view of the system and to understand the discrepancies between the experimental and theoretical values. The specific aim of this piece is to facilitate the process of constructing custom-made SD-OCT scanners for research groups with minimum understanding of concepts in optical design and medical imaging.

In vivo imaging with high-speed full-range complex spectral domain optical coherence tomography

2005 ◽  
Author(s):  
Erich Goetzinger ◽  
Michael Pircher ◽  
Rainer A. Leitgeb ◽  
Adolf F. Fercher ◽  
Christoph K. Hitzenberger
Keyword(s):  
Optical Coherence Tomography ◽  
In Vivo Imaging ◽  
High Speed ◽  
Full Range ◽  
Spectral Domain ◽  
Optical Coherence

scholarly journals Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Riham S. H. M. Allam ◽  
Rania A. Ahmed
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Normal Subjects ◽  
Cross Sectional Study ◽  
Spectral Domain ◽  
Outer Diameter ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Air Bubble ◽  
Inner Diameter

Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT).Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured.Results. 24 males and 52 females (mean age44±14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean412.16±163 μm), inner diameter (mean233.67±138.73 μm), and depth (mean251.7±126.58 μm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris.Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting.

In Vivo Assessment of Rodent Retinal Structure Using Spectral Domain Optical Coherence Tomography

2011 ◽  
pp. 489-494 ◽  
Author(s):  
M. Dominik Fischer ◽  
Gesine Huber ◽  
Francois Paquet-Durand ◽  
Peter Humphries ◽  
T. Michael Redmond ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Retinal Structure ◽  
In Vivo Assessment
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