scholarly journals Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

2019 ◽  
Vol 9 (13) ◽  
pp. 2580
Author(s):  
Joanna Stachura ◽  
Małgorzata Seredyka-Burduk ◽  
Ilona Piotrowiak-Słupska ◽  
Magdalena Kaszuba-Modrzejewska ◽  
Jagoda Rzeszewska-Zamiara ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Contact Lens ◽  
High Speed ◽  
Contact Lenses ◽  
Tear Film ◽  
Laser Source ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Swept Source Oct

Optical coherence tomography (OCT) is a high-speed and non-contact optical imaging technology widely used for noninvasive cross-sectional imaging of biological objects. Two main OCT technologies have been developed: time domain and Fourier domain technologies. The latter can be further divided into spectral domain OCT, which uses a broadband light source and a spectrometer as a detector, and swept source OCT, which employs a quickly-rotating laser source. Advances in OCT technology have made it one of the most helpful devices in ophthalmic practice. Fourier OCT has revolutionized imaging of the posterior segment of the eye, as well as of anterior structures and has enhanced the ability to diagnose and manage patients. It provides high-resolution information about the tear film, contact lens (CL), a qualitative and quantitative assessment of the anterior eye that is important in contact lens fitting, and allows possible eye surface changes while wearing contact lenses to be monitored. Potential swept source OCT technology applications include industrial processes of lens design and quality control. In this paper, we describe clinical applications and outline a variety of multifunctional uses of OCT in the field of refractive error correction with contact lenses.

A NEW AND MODERN DIGNOSTIC TECHNIQUE: SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY (SS-OCT)

2013 ◽  
Vol 5 (2) ◽  
pp. 31-33
Author(s):  
Prakash Lokhande
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Optical Imaging ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Non Invasive ◽  
Treatment Technologies ◽  
High Resolution Images ◽  
Swept Source Oct

ABSTRACT Innovative technique has been introduced in the field of dentistry for the purpose of diagnosis and treatment. Technologies like laser, composite curing techniques, optical imaging have been utilized in the field of dentistry. OCT(optical coherence tomography) is a recent. technique which creates cross-sectional high resolution images. SS-OCT(Swept -Source optical coherence tomography) is a variant of optical coherence tomography, which provides instant imaging with high resolution, non-invasive and ease of handling. This article provides a overview of Swept -Source OCT and its application in the field of dentistry.

scholarly journals Polarization sensitive optical coherence tomography utilizing a buffered swept source laser

2017 ◽  
Vol 3 (2) ◽  
pp. 227-230
Author(s):  
Jonas Golde ◽  
Lars Kirsten ◽  
Edmund Koch
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Fourier Domain ◽  
Optical Coherence ◽  
Swept Source ◽  
Finger Nail ◽  
Swept Source Oct ◽  
Human Finger

AbstractWe present an approach for polarization sensitive optical coherence tomography (PS-OCT) that solely requires a modification of the light source, a buffered swept source laser. For this purpose a single-mode fiber-based Fourier domain mode locked laser is extended by fourfold buffering with manual fiber polarization controllers to emit alternating sweep polarizations, while the polarization contrast calibration is realized by a high-speed polarimeter. As the introduced setup utilizes standard scanning and detection units, the proposed method is a promising way to enhance various swept source OCT systems by polarization sensitive imaging. Preliminary measurements of a human finger nail with different polarization contrasts demonstrate the feasibility of the concept.

DEVELOPMENT OF HIGH-SPEED SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY SYSTEM AT 1320 nm

2009 ◽  
Vol 02 (01) ◽  
pp. 117-122 ◽  
Author(s):  
TONG WU ◽  
ZHIHUA DING ◽  
MINGHUI CHEN ◽  
LEI XU ◽  
GUOHUA SHI ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Calibration Method ◽  
Wave Number ◽  
Laser Source ◽  
Depth Range ◽  
Optical Coherence ◽  
Swept Source ◽  
Human Finger

A swept-source optical coherence tomography (SSOCT) system based on a high-speed scanning laser source at center wavelength of 1320 nm and scanning rate of 20 kHz is developed. The axial resolution is enhanced to 8.3 μm by reshaping the spectrum in frequency domain using a window function and a wave number calibration method based on a Mach-Zender Interferometer (MZI) integrated in the SSOCT system. The imaging speed and depth range are 0.04 s per frame and 3.9 mm, respectively. The peak sensitivity of the SSOCT system is calibrated to be 112 dB. With the developed SSOCT system, optical coherence tomography (OCT) images of human finger tissue are obtained which enable us to view the sweat duct (SD), stratum corneum (SC) and epidermis (ED), demonstrating the feasibility of the SSOCT system for in vivo biomedical imaging.

scholarly journals Laser Lens Size Measurement Using Swept-Source Optical Coherence Tomography

2020 ◽  
Vol 10 (14) ◽  
pp. 4936
Author(s):  
Pingping Jia ◽  
Hong Zhao ◽  
Yuwei Qin
Keyword(s):  
Optical Coherence Tomography ◽  
High Speed ◽  
Wave Number ◽  
Radius Of Curvature ◽  
Optical Coherence ◽  
Swept Source ◽  
Laser Focusing ◽  
Fitting Algorithm ◽  
Laser Confocal Microscope ◽  
Focusing Lens

A high-speed, high-resolution swept-source optical coherence tomography (SS-OCT) is presented for focusing lens imaging and a k-domain uniform algorithm is adopted to find the wave number phase equalization. The radius of curvature of the laser focusing lens was obtained using a curve-fitting algorithm. The experimental results demonstrate that the measuring accuracy of the proposed SS-OCT system is higher than the laser confocal microscope. The SS-OCT system has great potential for surface topography measurement and defect inspection of the focusing lens.

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 Comparison between Widefield Optical Coherence Tomography Devices in Eyes with High Myopia

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 658
Author(s):  
Federico Corvi ◽  
Federico Zicarelli ◽  
Matteo Airaldi ◽  
Salvatore Parrulli ◽  
Mariano Cozzi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Myopia ◽  
Cross Sectional Study ◽  
Horizontal Line ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Image Artifact ◽  
Control Subjects ◽  
And Control

Background: To compare four different optical coherence tomography (OCT) devices for visualization of retinal and subretinal layers in highly myopic eyes. Methods: In this prospective, observational, cross-sectional study, consecutive patients with high myopia and control subjects were imaged by four OCT devices: Spectralis OCT2, PlexElite 2.0 100 kHz, PlexElite 2.0 200 kHz and the Canon Xephilio OCT-S1. The acquisition protocol for comparison consisted of single vertical and horizontal line scans centered on the fovea. Comparison between the devices in the extent of visible retina, presence of conjugate image or mirror artifacts, visibility of the sclerochoroidal interface and retrobulbar tissue. Results: 30 eyes with high myopia and 30 control subjects were analyzed. The visualized RPE length was significantly different between the OCT devices with Xephilio OCT-S1 imaging the largest extent (p < 0.0001). The proportion of eyes with conjugate image artifact was significantly higher with the Spectralis OCT (p < 0.0001), and lower with the PlexElite 200 kHz (p < 0.0001). No difference in visibility of the sclerochoroidal interface was noted among instruments. The retrobulbar tissue was visible in a higher proportion of eyes using swept-source PlexElite 100 kHz and 200 kHz (p < 0.007) compared to the other devices. Conclusions: In highly myopic eyes, the four OCT devices demonstrated significant differences in the extent of the retina imaged, in the prevalence of conjugate image artifact, and in the visualization of the retrobulbar tissue.

scholarly journals Swept Source Optical Coherence Tomography Angiography for Contact Lens-Related Corneal Vascularization

2016 ◽  
Vol 2016 ◽  
pp. 1-3 ◽  
Author(s):  
Marcus Ang ◽  
Yijun Cai ◽  
Anna C. S. Tan
Keyword(s):  
Optical Coherence Tomography ◽  
Image Quality ◽  
Contact Lens ◽  
Optical Coherence Tomography Angiography ◽  
Quality Score ◽  
Image Quality Score ◽  
Optical Coherence ◽  
Swept Source ◽  
Corneal Vascularization ◽  
Significant Difference

Purpose. To describe a novel technique of adapting a swept-source optical coherence tomography angiography (OCTA) to image corneal vascularization.Methods. In this pilot cross-sectional study, we obtained 3 × 3 mm scans, where 100,000 A-scans are acquired per second with optical axial resolution of 8 μm and lateral resolution of 20 μm. This was performed with manual “XYZ” focus without the anterior segment lens, until the focus of the corneoscleral surface was clearly seen and the vessels of interest were in focus on the corresponding red-free image. En face scans were evaluated based on image quality score and repeatability.Results. We analyzed scans from 10 eyes (10 patients) with corneal vascularization secondary to contact lens use in 4 quadrants, with substantial repeatability of scans in all quadrants (mean image quality score 2.7 ± 0.7;κ=0.75). There was no significant difference in image quality scores comparing quadrants (superior temporal: 2.9 ± 0.6, superior nasal: 2.8 ± 0.4, inferior temporal: 2.5 ± 0.9, and inferior nasal: 2.4 ± 1.0;P=0.276) and able to differentiate deep and superficial corneal vascularization.Conclusion. This early clinical study suggests that the swept-source OCTA used may be useful for examining corneal vascularization, which may have potential for clinical applications such as detecting early limbal stem cell damage.

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