1. All Articles

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    1. Chromatic dispersion effects in ultra-low coherence interferometry

      Chromatic dispersion effects in ultra-low coherence interferometry

      We consider the properties of an interference signal shift from zero-path-difference position in the presence of an uncompensated dispersive layer in one of the interferometer arms. It is experimentally shown that in using an ultra-low coherence light source, the formation of the interference signal is also determined by the group velocity dispersion, which results in a nonlinear dependence of the position of the interference signal on the geometrical thickness of the dispersive layer. The discrepancy in the dispersive layer and compensator refractive indices in the third decimal place is experimentally shown to lead to an interference signal shift that is ...

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    2. Early Phase Arterial Reaction Following Drug-Eluting and Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction Optical Coherence Tomography Assessment at 2 Weeks

      Early Phase Arterial Reaction Following Drug-Eluting and Bare-Metal Stent Implantation in Patients With ST-Segment Elevation Myocardial Infarction Optical Coherence Tomography Assessment at 2 Weeks

      The early phase arterial reaction after implantation of second-generation drug-eluting stents (2nd DES) and baremetal stents (BMS) in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear. The MECHANISM pilot study is a multi-center prospective registry that enrolled 24 STEMI patients (from 11 centers) who had undergone implantation of everolimus-eluting ( n = 6), biolimus A9-eluting ( n = 6) or zotarolimus-eluting stents ( n = 6), or BMS ( n = 6). Scheduled optical coherence tomography (OCT) was performed 2 weeks after implantation, and images were independently analyzed at a core laboratory in a blinded fashion. Intra-stent thrombus was quantitatively analyzed in terms of the maximal area ...

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    3. RefMoB, a Reflectivity Feature Model-Based Automated Method for Measuring Four Outer Retinal Hyperreflective Bands in Optical Coherence Tomography

      RefMoB, a Reflectivity Feature Model-Based Automated Method for Measuring Four Outer Retinal Hyperreflective Bands in Optical Coherence Tomography

      Purpose. : To validate a model-driven method (RefMoB) of automatically describing the four outer retinal hyperreflective bands revealed by spectral-domain optical coherence tomography (SDOCT), for comparison with histology of normal macula; to report thickness and position of bands, particularly band 2 (ellipsoid zone [EZ], commonly called IS/OS). Methods. : Foveal and superior perifoveal scans of seven SDOCT volumes of five individuals aged 28 to 69 years with healthy maculas were used (seven eyes for validation, five eyes for measurement). RefMoB determines band thickness and position by a multistage procedure that models reflectivities as a summation of Gaussians. Band thickness and positions ...

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    4. RETICULAR PSEUDODRUSEN ON INFRARED IMAGING ARE TOPOGRAPHICALLY DISTINCT FROM SUBRETINAL DRUSENOID DEPOSITS ON EN FACE OPTICAL COHERENCE TOMOGRAPHY

      RETICULAR PSEUDODRUSEN ON INFRARED IMAGING ARE TOPOGRAPHICALLY DISTINCT FROM SUBRETINAL DRUSENOID DEPOSITS ON EN FACE OPTICAL COHERENCE TOMOGRAPHY

      Purpose: To evaluate the quantitative and topographic relationship between reticular pseudodrusen (RPD) on infrared reflectance (IR) and subretinal drusenoid deposits (SDD) on en face volumetric spectral domain optical coherence tomography. Methods: Reticular pseudodrusen were marked on IR images by a masked observer. Subretinal drusenoid deposits were visualized on en face sections of spectral domain optical coherence tomography below the external limiting membrane and identified by a semiautomated technique. Control RPD lesions were generated in a random distribution for each IR image. Binary maps of control and experimental RPD and SDD were merged and analyzed in terms of topographic localization and ...

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    5. Optical coherence tomography in dermatology

      Optical coherence tomography in dermatology

      BACKGROUND: Optical coherence tomography (OCT) was first used in skin imaging in 1997, and since then the technology has undergone significant technological development. With its high resolution and moderate penetration depth OCT fills the imaging gap between High Frequency Ultrasound and Reflectance Confocal Microscopy. Different modalities of OCT have been developed either focusing on higher image resolution or special visualization of tissue with distinct optical properties, including collagen and blood flow. AIM: The aim of this study is to describe trends in OCT research on different dermatological diseases and review the results. METHODS: Pubmed, EMBASE, Web of science, Google Scholar ...

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    6. The prevalence of microcystic macular changes on optical coherence tomography of the macular region in optic nerve atrophy of non-neuritis origin: a prospective study

      The prevalence of microcystic macular changes on optical coherence tomography of the macular region in optic nerve atrophy of non-neuritis origin: a prospective study

      Background Microcystic macular changes, also called microcystic macular oedema, have recently been reported in patients with multiple sclerosis, particularly after optic neuritis. But it has since emerged that the finding is not specific for optic neuritis. This study was designed to prospectively investigate the prevalence of microcystic perifoveal changes in patients with optic atrophy not due to optic neuritis. Methods A prospective, cross-sectional study including 54 patients with a history of optic atrophy and 54 healthy control subjects. Spectral domain optical coherence tomography (SD-OCT) was used to scan the macular area and to measure the peripapillar retinal nerve fibre layer ...

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    7. Impact of segmentation errors and retinal blood vessels on retinal nerve fibre layer measurements using spectral-domain optical coherence tomography

      Impact of segmentation errors and retinal blood vessels on retinal nerve fibre layer measurements using spectral-domain optical coherence tomography

      Purpose To investigate the impact of retinal blood vessels and retinal nerve fibre layer (RNFL) segmentation errors on RNFL measurement. Methods One eye of 180 subjects (60 normal, 66 mild-to-moderate and 54 advanced glaucoma subjects) was randomly selected for RNFL imaging with a spectral-domain OCT. The boundaries of the RNFL detected by the instrument software were checked, and the segmentation errors were corrected by a customized computer program. The differences in average and regional RNFL thicknesses (RNFLT) before and after the correction were analysed to determine the frequency of segmentation error (defined as an absolute difference in average RNFLT >5 ...

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    8. Postdoctoral Positions in Biomedical Optics and Optical Coherence Tomography at the Center for Ophthalmic Optics & Lasers, Oregon Health & Science University

      Postdoctoral Positions in Biomedical Optics and Optical Coherence Tomography at the Center for Ophthalmic Optics & Lasers, Oregon Health & Science University

      Postdoctoral research opportunities are available in the area of biomedical optics at the Center for Ophthalmic Optics & Lasers ( www.COOLLab.net ) in the Casey Eye Institute, Oregon Health & Science University (OHSU). The COOL laboratory is a multidisciplinary team that incorporates optical scientists, image processing experts, ophthalmologists, statisticians, managers, and technicians. The group collaborates with several institutions to develop novel OCT technology, develop diagnostic and surgical planning software, and conduct clinical trials. The laboratory is well supported by the National Institutes of Health ( http://www.octnews.org/articles/2920025/optical-coherence-tomography-used-500m-of-federall/ ) and industry, and has brought many novel diagnostic technology into clinical ...

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    9. Correlation of spectral-domain optical coherence tomography with fundus fluorescein angiography in an infant with retinal hamartomas

      Correlation of spectral-domain optical coherence tomography with fundus fluorescein angiography in an infant with retinal hamartomas

      To describe the correlation between the surface morphology on spectral-domain optical coherence tomography (SD-OCT) and leakage pattern on fundus fluorescein angiography (FFA) in an infant with multiple retinal hamartomas. An Asian Indian female infant was found to have 2 retinal lesions in the right eye and 1 in the left eye during Retcam (Clarity MSI, CA, USA) screening for retinopathy of prematurity at 45 weeks postmenstrual age. Spectral-domain optical coherence tomography on the hand-held OCT (Envisu 2300, Bioptigen, NC, USA) and FFA on the Retcam 3 were performed under monitoring in the office. Spectral-domain OCT detected all 3 lesions but ...

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    10. OUTER RETINAL ATROPHY ON SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY AFTER RESOLUTION OF GLAUCOMA SURGERY-ASSOCIATED HYPOTONY MACULOPATHY

      OUTER RETINAL ATROPHY ON SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY AFTER RESOLUTION OF GLAUCOMA SURGERY-ASSOCIATED HYPOTONY MACULOPATHY

      Purpose: To report two cases of persistent central vision loss after resolution of filtration surgery-associated hypotony, corresponding with foveal outer retinal atrophy on spectral domain optical coherence tomography. Methods: Retrospective observational case series. A retrospective chart review was conducted of two patients with persistent vision loss after normalization of intraocular pressure and resolution of glaucoma surgery-associated hypotony maculopathy. Results: Several months after glaucoma surgery and resolution of hypotony, both patients suffered persistent vision loss and new foveal photoreceptor loss on spectral domain optical coherence tomography. Conclusion: This is the first case series demonstrating foveal outer retinal atrophy on spectral domain ...

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    11. Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus

      Comparison of Fourier-Domain and Time-Domain Optical Coherence Tomography in the Measurement of Thinnest Corneal Thickness in Keratoconus

      Objective . To compare fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT (TD-OCT) in the determination of thinnest corneal thickness (TCT). Methods . This study included 55 keratoconus patients and 50 healthy volunteers. The RTVue-OCT (FD-OCT) and Visante-OCT (TD-OCT) were used for the measurement of the TCT. Three consecutive scans were performed. The comparison and agreement between the two modalities were analyzed by paired t -test, the Pearson correlation, intraclass correlation coefficient (ICC), and Bland-Altman plots. intraobserver repeatability was analyzed by the intraobserver within-subject standard deviation ( ), coefficient of variation ( ), and ICC. Results . The TCT value of normal corneas was higher by RTVue-OCT ...

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    12. Hazy filling defect on coronary angiography: insights from optical coherence tomography

      Hazy filling defect on coronary angiography: insights from optical coherence tomography

      A middle-aged patient with previous stent to the left circumflex artery (LCx) 12 months before suffering from angina, now presented with acute-onset severe retrosternal chest pain with an ECG showing ST-elevation in the precordial leads (see online supplementary figure S1). He underwent emergency coronary angiography, which showed normal flow in all arteries and a patent LCx stent. The left anterior descending artery (LAD) contained a hazy filling defect in the mid vessel (figure 1A). Following administration of heparin, the filling defect in the mid-LAD resolved (figure 1B). The left ventriculogram showed severe systolic dysfunction involving the mid and apical segments ...

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    13. Sequential Optical Coherence Tomographic Angiography for Diagnosis and Treatment of Choroidal Neovascularization in Multifocal Choroiditis

      Sequential Optical Coherence Tomographic Angiography for Diagnosis and Treatment of Choroidal Neovascularization in Multifocal Choroiditis

      This case report describes choroidal neovascularization in multifocal choroiditis diagnosed using optical coherence tomographic angiography. Accurate diagnosis of choroidal neovascularization (CNV) is critical to ensure timely anti–vascular endothelial growth factor therapy and preclude loss of visual acuity. Dye-based angiography is the gold standard for CNV diagnosis; however, it is invasive, is associated with risk of allergy, and may be limited by availability. Optical coherence tomography (OCT) angiography (OCTA) is a noninvasive, non–dye-based modality that generates en face images (OCT angiograms) of retinal and choroidal vascular layers. 1 - 4 This is one of the first reports, to our knowledge ...

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    14. Spectral-domain optical coherence tomography and fundus autofluorescence features in a case of typical retinocytoma

      Spectral-domain optical coherence tomography and fundus autofluorescence features in a case of typical retinocytoma

      To report spectral-domain optical coherence tomography (OCT) and fundus autofluorescence (FAF) features observed in a case of typical retinocytoma. Case report. A 17-year-old girl on routine ophthalmologic evaluation for headache had an elevated translucent lesion with peripheral pigmentation and adjacent chorioretinal atrophy close to the disc in the nasal retinal quadrant of the left eye. The lesion was confirmed to be retinocytoma on fluorescein angiography. Optical coherence tomography revealed a hyperreflective layer akin to preserved nerve fiber layer overlying the lesion in most of the scans. Symmetrical hyporeflective spaces in the underlying choroid and at places sudden disruption of choroid ...

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    15. SUBMILLIMETER CHOROIDAL MELANOMA DETECTION BY ENHANCED DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHY IN A PATIENT WITH OCULODERMAL MELANOCYTOSIS

      SUBMILLIMETER CHOROIDAL MELANOMA DETECTION BY ENHANCED DEPTH IMAGING OPTICAL COHERENCE TOMOGRAPHY IN A PATIENT WITH OCULODERMAL MELANOCYTOSIS

      Purpose: To describe a tiny subclinical choroidal melanoma visualized only with enhanced depth imaging optical coherence tomography in a newly symptomatic patient with known oculodermal melanocytosis. Methods: Case report. Results: A 52-year-old white man with heterochromia and known oculodermal melanocytosis of the right eye, followed for 2 years without change, developed blurred vision and was referred for possible central serous chorioretinopathy. On examination, visual acuity was 20/20 in each eye. There was oculodermal melanocytosis in the right eye involving the periocular skin, episclera, iris, and choroid. On ophthalmoscopy and ocular ultrasonography, there was no appreciable mass, but subtle subfoveal ...

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    16. Automated, Depth Resolved Estimation of the Attenuation Coefficient From Optical Coherence Tomography Data

      Automated, Depth Resolved Estimation of the Attenuation Coefficient From Optical Coherence Tomography Data

      We present a method for automated , depth - resolved extraction of the attenuation coefficient from Optical Coherence Tomography (OCT) data . In contrast to previous automated , depth - resolved methods, the Depth - Resolved Confocal (DRC) technique derives an invertible mapping between the measured OCT intensity data and the attenuation coefficient while considering the confocal function and sensitivity fall-off, which are critical to ensure accurate measurements of the attenuation coefficient in practical settings (e.g., clinical endoscopy). We also show that further improvement of the estimated attenuation coefficient is possible by formulating image denoising as a convex optimization problem that we term IntensityWeighted Horizontal ...

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    17. Structural Changes in Pseudoexfoliation Syndrome Evaluated with Spectral Domain Optical Coherence Tomography

      Structural Changes in Pseudoexfoliation Syndrome Evaluated with Spectral Domain Optical Coherence Tomography

      Purpose : To detect early structural changes of macular ganglion cell complex (GCC), peripapillary nerve fiber layer (pNFL), and optic nerve head (ONH) topography in subjects with pseudoexfoliation (PEX) using 3-D spectral domain optical coherence tomography (SD-OCT, Topcon 3D-2000). Materials and Methods : Thirty-five participants with PEX and 29 healthy control subjects were included in the study. All study participants underwent SD-OCT imaging. Macular NFL, ganglion cell layer and inner plexiform layer (GCL + IPL), pNFL, and ONH parameters were measured in each participant. The results were compared within the two groups. Results : In eyes with PEX, the superior and total mNFL thickness ...

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    18. Investigation of optical coherence micro-elastography as a method to visualize cancers in human breast tissue

      Investigation of optical coherence micro-elastography as a method to visualize cancers in human breast tissue

      Accurate intraoperative identification of malignant tissue is a challenge in the surgical management of breast cancer. Imaging techniques that help address this challenge could contribute to more complete and accurate tumor excision, and thereby help reduce the current high re-excision rates without resorting to the removal of excess healthy tissue. Optical coherence micro-elastography (OCME) is a three-dimensional, high-resolution imaging technique that is sensitive to micro-scale variations of the mechanical properties of tissue. As tumor modifies the mechanical properties of breast tissue, OCME has the potential to identify, on the micro-scale, involved regions of fresh, unstained tissue. OCME is based on ...

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    19. Rapid scanning catheterscope for expanded forward-view volumetric imaging with optical coherence tomography

      Rapid scanning catheterscope for expanded forward-view volumetric imaging with optical coherence tomography

      We demonstrate a novel catheterscope, based on scanning fiber endoscopy, for volumetric imaging with optical coherence tomography (OCT), which possesses a high resonance frequency ( > 2     kHz ) and a small outer diameter (OD) (1.07 mm). Our design is the fastest volumetric-scanning, forward-viewing catheterscope for OCT, and the scanning package has the smallest OD of any such OCT package published to date. Using a proof-of-operation catheterscope with commercial lenses, we demonstrate high-quality in vivo and ex vivo volumetric imaging and extend the 1.1 mm diameter field of view more than 200-fold by mosaicking. Due to its small OD, short rigid ...

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    20. Detection of buried Barrett’s glands after radiofrequency ablation with volumetric laser endomicroscopy

      Detection of buried Barrett’s glands after radiofrequency ablation with volumetric laser endomicroscopy

      Background and Aims The prevalence and clinical relevance of buried Barrett’s glands (BB) after radiofrequency ablation (RFA) in Barrett’s esophagus (BE) are debated. Recent optical coherence tomography studies demonstrated a high prevalence of BBs. Direct histological correlation, however, has been lacking. Volumetric laser endomicroscopy (VLE) is a second-generation optical coherence tomography system capable of scanning a large surface of the esophageal wall layers with low-power microscopy resolution. The aim was to evaluate whether post-RFA subsquamous glandular structures (SGSs), detected with VLE, actually correspond to BBs by pursuing direct histological correlation with VLE images. Methods In vivo VLE was ...

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    21. St. Jude Medical Announces Launch of the First International Trial to Compare OCT-Guided Stent Implantation to IVUS or Angiography-Guided PCI

      St. Jude Medical Announces Launch of the First International Trial to Compare OCT-Guided Stent Implantation to IVUS or Angiography-Guided PCI

      St. Jude Medical, Inc. (NYSE:STJ), a global medical device company, today announced the launch of the ILUMIEN III clinical trial, a prospective, international, randomized trial evaluating the clinical benefits of the company’s optical coherence tomography (OCT) guidance during stent implantation. The ILUMIEN III study will compare OCT-guided stent implantation to implantation guided by intravascular ultrasound (IVUS) or angiography alone, diagnostic tools that offer less resolution than OCT during intravascular assessments and percutaneous coronary intervention (PCI). The ILUMIEN III study is the largest multicenter randomized study to date to compare PCI outcomes associated with all three imaging tools. By ...

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    22. Optovue Introduces AngioVue OCTA in Glaucoma

      Optovue Introduces AngioVue OCTA in Glaucoma

      Optovue, a pioneer in optical coherence tomography angiography (OCTA) and leader in commercialization of the technology, announced that it has expanded the application of its OCT Angiography technology into glaucoma. After a successful introduction of the revolutionary AngioVue Imaging System to retina last year, Optovue has worked to develop clinical applications in glaucoma as well.

      The use of the AngioVue Imaging System in glaucoma was introduced at a highly successful symposium at the 6th World Glaucoma Congress in Hong Kong. The Optovue-hosted event featured presentations on the clinical applications of OCTA in glaucoma research using the company's AngioVue OCTA ...

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    23. Bringing the human eye into focus

      Bringing the human eye into focus

      A new computer algorithm, to correct optical aberrations that appear while imaging the back of the eye, has been demonstrated by researchers in the US. The team's method should allow the benefits of adaptive optics, more commonly used in astronomy, to be brought more readily into clinics. It does not need expensive optical hardware and, according to the researchers, could help diagnose degenerative eye and neurological diseases earlier, making their treatment more successful. Optical coherence tomography is an interferometry-based medical imaging technique analogous to ultrasound imaging, but using light instead of sound. It is the standard of care for ...

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    24. High-resolution three-dimensional in vivo imaging of mouse oviduct using optical coherence tomography

      High-resolution three-dimensional in vivo imaging of mouse oviduct using optical coherence tomography

      The understanding of the reproductive events and the molecular mechanisms regulating fertility and infertility in humans relies heavily on the analysis of the corresponding phenotypes in mouse models. While molecular genetic approaches provide significant insight into the molecular regulation of these processes, the lack of live imaging methods that allow for detailed visualization of the mouse reproductive organs limits our investigations of dynamic events taking place during the ovulation, the fertilization and the pre-implantation stages of embryonic development. Here we introduce an in vivo three-dimensional imaging approach for visualizing the mouse oviduct and reproductive events with micro-scale spatial resolution using ...

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