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https://read.qxmd.com/read/30775105/quantitative-analysis-of-choriocapillaris-in-non-human-primates-using-swept-source-optical-coherence-tomography-angiography-ss-octa
#1
Bingyao Tan, Jacqueline Chua, Veluchamy Amutha Barathi, Mani Baskaran, Anita Chan, Emily Lin, Marcus Ang, Gerd Klose, Leopold Schmetterer
The choriocapillaris is a unique vascular plexus located posterior to the retinal pigment epithelium. In recent years, there is an increasing interest in the examination of the interrelationship between the choriocapillaris and eye diseases. We used several techniques to study choroidal perfusion, including laser Doppler flowmetry, laser speckle flowgraphy, and optical coherence tomography angiography (OCTA), but with the latter no standardized algorithm for quantitative analysis has been provided. We analyzed different algorithms to quantify flow voids in non-human primates that can be easily implemented into clinical research...
January 1, 2019: Biomedical Optics Express
https://read.qxmd.com/read/30775082/megahertz-rate-optical-coherence-tomography-angiography-improves-the-contrast-of-the-choriocapillaris-and-choroid-in-human-retinal-imaging
#2
Justin V Migacz, Iwona Gorczynska, Mehdi Azimipour, Ravi Jonnal, Robert J Zawadzki, John S Werner
Angiographic imaging of the human eye with optical coherence tomography (OCT) is becoming an increasingly important tool in the scientific investigation and clinical management of several blinding diseases, including age-related macular degeneration and diabetic retinopathy. We have observed that OCT angiography (OCTA) of the human choriocapillaris and choroid with a 1.64 MHz A-scan rate swept-source laser yields higher contrast images as compared to a slower rate system operating at 100 kHz. This result is unexpected because signal sensitivity is reduced when acquisition rates are increased, and the incident illumination power is kept constant...
January 1, 2019: Biomedical Optics Express
https://read.qxmd.com/read/30770133/three-dimensional-assessment-of-proximal-contact-enamel-using-optical-coherence-tomography
#3
Thwe Zin Ei, Yasushi Shimada, Ahmed Abdou, Alireza Sadr, Masahiro Yoshiyama, Yasunori Sumi, Junji Tagami
OBJECTIVE: The purpose of this study was to detect and investigate the association of enamel microcracks with demineralization at proximal contact areas of premolars, using 3D swept-source optical coherence tomography (SS-OCT). METHODS: Extracted maxillary and mandibular premolars (n=50 each), without any visible tooth cracks, were examined for demineralization of interproximal contact areas, using the International Caries Detection and Assessment System (ICDAS)...
February 12, 2019: Dental Materials: Official Publication of the Academy of Dental Materials
https://read.qxmd.com/read/30768226/choroidal-vascularity-index-using-swept-source-and-spectral-domain-optical-coherence-tomography-a-comparative-study
#4
Rupesh Agrawal, Sophia Seen, Shiva Vaishnavi, Kiran Kumar Vupparaboina, Abhilash Goud, Mohammed Abdul Rasheed, Jay Chhablani
BACKGROUND AND OBJECTIVE: Choroidal vascularity index (CVI) is a noninvasive tool to assess choroidal structure. The objective of the current study was to compare the CVI measurements on swept-source optical coherence tomography (SS-OCT) and spectral-domain OCT (SD-OCT) scans using the same image binarization protocol. PATIENTS AND METHODS: This prospective study was conducted from July 2016 through January 2017 and involved 54 healthy volunteers at a tertiary referral eye care institute in Southern India...
February 1, 2019: Ophthalmic Surgery, Lasers & Imaging Retina
https://read.qxmd.com/read/30768218/imaging-of-epiretinal-membranes-using-en-face-widefield-swept-source-optical-coherence-tomography
#5
Elie Motulsky, Fang Zheng, Yingying Shi, José M B Garcia, Giovanni Gregori, Philip J Rosenfeld
BACKGROUND AND OBJECTIVE: Swept-source optical coherence tomography (SS-OCT) imaging was performed on eyes with epiretinal membranes (ERMs), and the extent of the ERMs were compared between the 12 mm × 12 mm scans and the more routine 6 mm × 6 mm field of view (FOV). PATIENTS AND METHODS: Eyes containing ERMs were imaged using a 12 mm × 12 mm SS-OCT scan. En face images derived from vitreoretinal interface (VRI) slabs were reviewed to assess the full extent of the ERM...
February 1, 2019: Ophthalmic Surgery, Lasers & Imaging Retina
https://read.qxmd.com/read/30767987/compression-optical-coherence-elastography-with-two-dimensional-displacement-measurement-and-local-deformation-visualization
#6
En Li, Shuichi Makita, Shinnosuke Azuma, Arata Miyazawa, Yoshiaki Yasuno
Current compression-based optical coherence elastography (OCE) only measures the axial displacement of a tissue, although the tissue also undergoes lateral displacement and microstructural alteration by the compression. In this Letter, we demonstrate a new compression-based OCE method that visualizes not only axial displacement, but also lateral displacement and microstructural decorrelation (MSD). This method employs complex correlation-based displacement and MSD measurements. It is implemented in a swept-source optical coherence tomography system with an active submicrometer compression...
February 15, 2019: Optics Letters
https://read.qxmd.com/read/30742226/comprehensive-comparison-of-axial-length-measurement-with-three-swept-source-oct-based-biometers-and-partial-coherence-interferometry
#7
Jinhai Huang, Hao Chen, Yue Li, Zhongxing Chen, Rongrong Gao, Jinjin Yu, Yune Zhao, Weicong Lu, Colm McAlinden, Qinmei Wang
PURPOSE: To compare axial length measurements (and failure rate) of three swept-source optical coherence tomography (SS-OCT)-based biometers: IOLMaster 700 (Carl Zeiss Meditec, Jena, Germany), OA-2000 (Tomey, Nagoya, Japan), and Argos (Movu Inc., Komaki, Japan) to those provided by a partial coherence interferometry (PCI)-based optical biometer (IOLMaster v5.4 [Carl Zeiss Meditec]). METHODS: A total of 119 patients (171 eyes) undergoing cataract surgery were enrolled...
February 1, 2019: Journal of Refractive Surgery
https://read.qxmd.com/read/30733871/abnormal-outer-choroidal-vasculature-in-amblyopia
#8
Noriko Terada, Manabu Miyata, Yuki Muraoka, Masayuki Hata, Masahiro Fujimoto, Satoshi Yokota, Hideo Nakanishi, Kenji Suda, Munemitsu Yoshikawa, Sotaro Ooto, Hiroshi Ohtsuki, Akitaka Tsujikawa
Purpose: Several studies have indicated morphological changes in the choroid in amblyopia cases. This study investigates whether choroidal vasculature was different among amblyopic and fellow eyes in unilateral amblyopia patients and healthy eyes, using en face images acquired via swept-source optical coherence tomography (SS-OCT). Design: Prospective, observational case-control study. Methods: This study included 14 consecutive patients with unilateral amblyopia and 22 age- and axial length-matched healthy eyes...
2019: Journal of Ophthalmology
https://read.qxmd.com/read/30733067/choroidal-neovascularisation-secondary-to-serpiginous-choroiditis-the-value-of-oct-angiography-in-diagnosis-and-response-to-therapy-with-aflibercept
#9
R Campos Polo, C Rubio Sánchez, A Sánchez Trancón
A case is presented of a 61 year-old man with a personal history of serpiginous choroiditis (SC), who presented with metamorphopsia and decreased visual acuity (VA) in his right eye (RE). In the examination, using Swept Source OCT-angiography (SS OCT-A), peripapillary haemorrhage secondary to a choroidal neovascularisation (CNV) was observed. The patient was treated with intravitreal aflibercept, having a favourable outcome on his symptomatology and in the SS OCT-A findings. CNV is a complication that can appear in up to 25% of cases after SC...
February 4, 2019: Archivos de la Sociedad Española de Oftalmología
https://read.qxmd.com/read/30732385/detection-of-laser-induced-bulk-damage-in-optical-crystals-by-swept-source-optical-coherence-tomography
#10
Fang Hou, Muyang Zhang, Yinbo Zheng, Lei Ding, Xiaodong Tang, Yanmei Liang
An approach to characterize laser-induced bulk damage in optical crystal materials was demonstrated. With a homemade swept-source optical coherence tomography (SS-OCT) system, we obtained three-dimensional images of the bulk damage produced by laser pulses with wavelength of 351 nm, pulse width of 5 ns, beam diameter of 5.5 mm and fluences from 4.56 J/cm2 to 9.95 J/cm2 in Potassium Dihydrogen Phosphate (KDP) crystal. Algorithms based on three-dimensional OCT images were specially designed to count and locate bulk damage pinpoints in KDP crystal, obtaining their equivalent diameter distribution and pinpoint density caused by different fluences...
February 4, 2019: Optics Express
https://read.qxmd.com/read/30732227/resonant-antiresonant-coupled-cavity-vcsels
#11
Kevin T Cook, Pengfei Qiao, Jipeng Qi, Larry A Coldren, Connie J Chang-Hasnain
The wavelength tuning range of a tunable vertical-cavity surface-emitting laser (VCSEL) is strongly influenced by the design of the interface between the semiconductor cavity and the air cavity. A simplified model is used to investigate the origin of the dramatic differences in free spectral range (FSR) and tuning slope observed in semiconductor cavity dominant, extended cavity, and air cavity dominant VCSELs. The differences arise from the positioning of the resonant and antiresonant wavelengths of the semiconductor cavity with respect to the center wavelength...
February 4, 2019: Optics Express
https://read.qxmd.com/read/30721901/microvascular-retinal-and-choroidal-changes-in-retinal-vein-occlusion-analyzed-by-two-different-optical-coherence-tomography-angiography-devices
#12
Eliana Costanzo, Mariacristina Parravano, Marta Gilardi, Michele Cavalleri, Riccardo Sacconi, Emanuela Aragona, Monica Varano, Francesco Bandello, Giuseppe Querques
PURPOSE: To investigate retinal and choroidal microvascular changes and structural choroidal involvement in retinal vein occlusion (RVO). METHODS: Retrospective analysis of treatment-naïve macular edema secondary to RVO, studied by optical coherence tomography (OCT) and OCT angiography (OCTA), before and after the loading phase of intravitreal injections of ranibizumab (IVR-LP). OCTA was performed using two different devices: AngioVue RTVue XR Avanti (spectral-domain OCTA) and Zeiss PLEX® Elite 9000 (swept-source OCTA)...
February 5, 2019: Ophthalmologica. Journal International D'ophtalmologie
https://read.qxmd.com/read/30720573/impact-of-cataract-surgery-on-filtering-bleb-morphology-identified-via-swept-source-three-dimensional-anterior-segment-optical-coherence-tomography
#13
Akiko Narita, Yuki Morizane, Tomoe Miyake, Kae Sugihara, Tomoko Ishikawa, Jiro Seguchi, Fumio Shiraga
PURPOSE: To identify the cross-sectional morphological changes in successful filtering blebs after phacoemulsification using swept-source three-dimensional anterior segment optical coherence tomography (3D AS-OCT). MATERIALS AND METHODS: Thirty phakic eyes of 29 patients with successful filtering blebs after primary trabeculectomy were included in this retrospective cohort study. Success was defined as intraocular pressure (IOP)≤15▒mmHg and a>20% reduction in IOP without glaucoma medication or additional glaucoma surgery after trabeculectomy...
February 1, 2019: Journal of Glaucoma
https://read.qxmd.com/read/30713283/detection-of-enamel-subsurface-lesions-by-swept-source-optical-coherence-tomography
#14
Sumiyo Suzuki, Yu Kataoka, Masafumi Kanehira, Mikihiro Kobayashi, Takashi Miyazaki, Atsufumi Manabe
This study aimed to non-destructively analyze the progression of subsurface enamel caries using swept-source optical coherence tomography (SS-OCT), a recently developed imaging analysis modality. Artificial enamel caries at various stages of demineralization were created in bovine tooth enamel using a modified lactic acid gel system. Untreated enamel served as a control. OCT images from cross-sections of enamel were collected. Mineral density, distribution, and histological changes were analyzed using an electron probe microanalyzer, scanning electron microscopy, and contact microradiography...
February 1, 2019: Dental Materials Journal
https://read.qxmd.com/read/30709810/microperimetry-in-age-related-macular-degeneration-association-with-macular-morphology-assessed-by-optical-coherence-tomography
#15
Miin Roh, Inês Laíns, Hyun Joon Shin, Dong Ho Park, Steven Mach, Demetrios G Vavvas, Ivana K Kim, Joan W Miller, Deeba Husain, John B Miller
BACKGROUND/AIMS: Microperimetry is a technique that is increasingly used to assess visual function in age-related macular degeneration (AMD). In this study, we aimed to evaluate the relationship between retinal sensitivity measured with macular integrity assessment (MAIA) microperimetry and optical coherence tomography (OCT)-based macular morphology in AMD. METHODS: Prospective, cross-sectional study. All participants were imaged with colour fundus photographs used for AMD staging (Age-Related Eye Disease Study scale), spectral-domain OCT (Spectralis, Heidelberg, Germany) and swept-source OCT (Topcon, Japan)...
February 1, 2019: British Journal of Ophthalmology
https://read.qxmd.com/read/30705996/hypertensive-choroidopathy-multimodal-imaging-and-the-contribution-of-wide-field-swept-source-oct-angiography
#16
Amina Rezkallah, Laurent Kodjikian, Amro Abukhashabah, Philippe Denis, Thibaud Mathis
Purpose: To present the case of a patient with a hypertensive choroidopathy and her follow-up using multimodal imaging; and to assess how wide-field swept-source (SS) Optical Coherence Tomography Angiography (OCTA) contributes to detecting the areas of hypoperfusion. Observations: A 25-year-old white woman with terminal renal insufficiency, myopericarditis, and cerebrospinal fluid pressure of 37 mmHg indicating intracranial hypertension, presented with a painless loss of vision in both eyes...
March 2019: American Journal of Ophthalmology Case Reports
https://read.qxmd.com/read/30703442/optical-coherence-tomography-based-diagnostic-criteria-for-different-stages-of-myopic-maculopathy
#17
Yuxin Fang, Ran Du, Natsuko Nagaoka, Tae Yokoi, Kosei Shinohara, Xian Xu, Hiroyuki Takahashi, Yuka Onishi, Takeshi Yoshida, Kyoko Ohno-Matsui
PURPOSE: To analyze the choroidal thickness (CT) of each type of myopic maculopathy, and to establish an OCT-based classification of myopic maculopathy. DESIGN: Retrospective, hospital-based, cross-sectional study. PARTICIPANTS: Highly myopic (HM) eyes that were examined by swept-source OCT. METHODS: The CT was measured at the subfovea and at 3 mm nasal, temporal, superior, and inferior to the fovea. Myopic maculopathy was classified as tessellation, diffuse atrophy, patchy atrophy, and macular atrophy (MA) based on the fundus photographs...
January 28, 2019: Ophthalmology
https://read.qxmd.com/read/30701164/quantifying-choriocapillaris-flow-deficits-using-global-and-localized-thresholding-methods-a-correlation-study
#18
Zhongdi Chu, Qinqin Zhang, Hao Zhou, Yingying Shi, Fang Zheng, Giovanni Gregori, Philip J Rosenfeld, Ruikang K Wang
Background: To investigate the correlation and agreement of two previously published choriocapillaris (CC) quantification methods using a normal database with swept-source optical coherence tomography angiography (SS-OCTA). Methods: Normal adult subjects from all age groups imaged by SS-OCTA were used in this study. Each subject was imaged with 3 mm × 3 mm and 6 mm × 6 mm scan patterns centered on fovea, upon which en face CC images were generated by segmenting volumetric OCTA data...
December 2018: Quantitative Imaging in Medicine and Surgery
https://read.qxmd.com/read/30696165/compressed-sensing-enabled-phase-sensitive-swept-source-optical-coherence-tomography
#19
Yuye Ling, William Meiniel, Rajinder Singh-Moon, Elsa Angelini, Jean-Christophe Olivo-Marin, Christine P Hendon
Here we present a novel phase-sensitive swept-source optical coherence tomography (PhS-SS-OCT) system. The simultaneously recorded calibration signal, which is commonly used in SS-OCT to stabilize the phase, is randomly sub-sampled during the acquisition, and it is later reconstructed based on the Compressed Sensing (CS) theory. We first mathematically investigated the method, and verified it through computer simulations. We then conducted a vibrational frequency test and a flow velocity measurement in phantoms to demonstrate the system's capability of handling phase-sensitive tasks...
January 21, 2019: Optics Express
https://read.qxmd.com/read/30689605/changes-in-intraocular-pressure-and-angle-status-after-phacoemulsification-in-primary-angle-closure-hypertension
#20
Harathy Selvan, Dewang Angmo, Ankit S Tomar, Suresh Yadav, Arpit Sharma, Tanuj Dada
PURPOSE: To study the change in intraocular pressure (IOP) and angle status after phacoemulsification in a cohort of primary angle closure hypertension (PACHT) patients. SETTING: Tertiary Eye Care, India. DESIGN: Prospective interventional case-series. METHODS: Case-series of 18 eyes of 18 patients. Preoperative biometry including axial length, anterior chamber depth (ACD), lens thickness, and central corneal thickness were studied...
February 2019: Journal of Glaucoma
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