1. Depth-resolved Imaging and Displacement Measurement Techniques Viewed as Linear Filtering Operations

    Explore Article SpringerLink Home (Aug 17 2010)

    Depth-resolved Imaging and Displacement Measurement Techniques Viewed as Linear Filtering Operations The last 5 years have seen the emergence of a family of optical interferometric techniques that provide deformation measurements throughout three-dimensional (3-D) weakly scattering materials. They include wavelength scanning interferometry (WSI), tilt scanning interferometry (TSI), phase contrast spectral optical coherence tomography (PC SOCT) and hyperspectral interferometry (HSI) and can be thought of as a marriage between the phase sensing capabilities of Phase Shifting Interferometry and the depth-sensing capabilities of Optical Coherence Tomography. It was recently shown that some closely related 3-D optical imaging techniques can be treated as shift-invariant linear filtering operations. In this paper, we extend that work to ... (Read Full Article)

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  2. Evolution from macular pseudohole to lamellar macular hole — spectral domain OCT study

    Explore Article SpringerLink Home (Aug 11 2010)

    Evolution from macular pseudohole to lamellar macular hole — spectral domain OCT study Abstract Background The pathogenesis of macular pseudohole (MPH) is supposed to be different from that of macular lamellar hole (LMH). MPH is thought to be caused by centripetal contraction of previously present epiretinal membrane. LMH is considered to be an effect of abortive process of full-thickness macular hole formation, or a result of de-roofing of a foveal cyst in persistent cystoid macular oedema. In most cases of LMH, epiretinal membranes are present. The aim of this paper is to show that LMH and MPH may have a common origin and that LMH may evolve from MPH as an epiretinal membrane ... (Read Full Article)

    Comment on Article Mentions:   Jerzy Nawrocki   Optopol Technology   Jasne Blonia Eye Clinic

  3. Localized retinal nerve fiber layer defects associated with cotton wool spots

    Explore Article SpringerLink Home (Aug 10 2010)

    Localized retinal nerve fiber layer defects associated with cotton wool spots Purpose To introduce four cases of localized retinal nerve fiber layer (RNFL) defects after emergence of retinal cotton wool spots (CWSs). Methods Four patients were evaluated for localized RNFL defects after the appearance of CWSs. Depending on the patient, they were followed up from the beginning of treatment to up to 19 years after the initial events. Fundus photos and other glaucoma examinations, including Stratus optical coherence tomography (OCT) and visual field examinations, were performed during the follow-up visits. Results The localized RNFL defects remained stable without any progression for as long as 19 years. Conclusions Nonprogressive RNFL defects may ... (Read Full Article)

    Comment on Article Mentions:   Zeiss Stratus OCT   Sungkyunkwan University   Seoul National University

  4. A Retinal Layer Structure Analysis to Measure the Size of Disease Using Layer Boundaries Detection for Optical Coherence Tomography Images

    Explore Article SpringerLink Home (Aug 9 2010)

    A Retinal Layer Structure Analysis to Measure the Size of Disease Using Layer Boundaries Detection for Optical Coherence Tomography Images In the field of ophthalmology, optical coherence tomography (OCT) is rapidly becoming popular in clinical applications to diagnose retinal disease. In this paper, we proposed a new profile analysis to evaluate the size of the retinal disease using the number of layer boundaries. The number is established by a new analysis method of a gray level profile scanned in longitudinal direction for an OCT image. We employed the proposed method for 50 OCT images of normal retina and 50 OCT images of abnormal retina. The experiment result showed that a significant difference was obtained in the significance level at 1%, ... (Read Full Article)

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  5. Extraction Method of Retinal Border Lines in Optical Coherence Tomography Image by Using Dynamic Contour Model

    Explore Article SpringerLink Home (Aug 9 2010)

    Extraction Method of Retinal Border Lines in Optical Coherence Tomography Image by Using Dynamic Contour Model In the field of ophthalmology, the needs of retina diagnosis using optical coherence tomography (OCT) images have been growing, and the automatic measurement of a retina thickness and its quantitative evaluation are desired for the diagnosis of retinal diseases. Previously, the automatic measurement methods of the retinal thickness have been reported for retinal OCT images. These previous methods can extract the retinal border lines (ILM and RPE) appropriately in most cases of normal OCT image. However these methods caused the tracking error to some OCT images with large noises. In this paper, we propose a new automatic measurement method of ... (Read Full Article)

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  6. Laser Sources for Confocal Microscopy

    Explore Article SpringerLink Home (Aug 4 2010)

    Laser Sources for Confocal Microscopy Laser assisted confocal microscopy has made a lot of progress over the past few years. Laser systems have become more modular and compact. There is an ever-increasing number of available laser excitation lines as well as an improvement in user friendliness and ease of use. At the same time, expansion of Web resources has provided easy access to a wealth of information. Ouf goal is both to aid the experienced and novice microscopist in quickly locating and sorting through the relevant laser information and to provide a means of avoiding common problems and pitfalls in the use of laser excitation ... (Read Full Article)

    Comment on Article Mentions:   University of Illinois at Urbana-Champaign

  7. In vivo quantification of propylene glycol, glucose and glycerol diffusion in human skin with optical coherence tomography

    Explore Article SpringerLink Home (Aug 3 2010)

    In vivo quantification of propylene glycol, glucose and glycerol diffusion in human skin with optical coherence tomography The purpose of study is to quantify and compare diffusion of propylene glycol, glucose, glycerol in the human skin in vivo noninvasively. Optical coherence tomography (OCT) was utilized in the functional imaging of optical cleaning agents for monitoring and quantifying the permeability coefficients (PCs) of them. Our experiments showed that the permeability coefficient of 40% propylene glycol from different subjects was averaged and found to be (2.52 ± 0.02) × 10−6 cm/s, the permeability coefficient of 40% glucose was (1.94 ± 0.05) × 10−6 cm/s, and the permeability coefficient of 40% glycerol was (1.82 ± 0.04) × 10−6 cm/s. The ... (Read Full Article)

    Comment on Article Mentions:   Sun Yat-Sen University

  8. Statistical Analysis of Retinal Tomographic Pseudo Images for Diagnostic Purpose

    Explore Article SpringerLink Home (Jul 23 2010)

    Statistical Analysis of Retinal Tomographic Pseudo Images for Diagnostic Purpose The majority of visual impairments are related to retinal disorders. Therefore, techniques useful for early detection of retinal anomalies are of great interest for diagnosis and treatment of related pathologies. Optical Coherence Tomography (OCT) is a non-invasive technique that is becoming increasingly important in the analysis of human retina. This technique produces sections of a three dimensional reflectance map, which are pseudo-images of the retinal structure. In these pseudo-images, early pathologies may produce local modifications of reflectance, which visually, appear as blots. Consequently, automatic procedures for detection of such blots may be of help in the diagnosis of many retinal ... (Read Full Article)

    Comment on Article Mentions:   University of Southern California   David Huang   Ou Tan

  9. Continuous optical coherence tomography monitoring of nanoparticles accumulation in biological tissues

    Explore Article SpringerLink Home (Jul 16 2010)

    Continuous optical coherence tomography monitoring of nanoparticles accumulation in biological tissues In this study, dynamics of nanoparticles penetrating and accumulating in biotissue (healthy skin) was investigated in vivo by the noninvasive method of optical coherence tomography (OCT). Gold nanoshells and titanium dioxide nanoparticles were studied. The processes of the nanoparticles penetration and accumulation in biotissue are accompanied by the changes in optical properties of skin which affect the OCT images. The continuous OCT monitoring of the process of the nanoparticles penetration into skin showed that these changes appeared in 30 min after application of nanoparticles on the surface; the time of accumulation of maximal nanoparticles concentration in skin was observed in ... (Read Full Article)

    Comment on Article Mentions:   Nizhny Novgorod State Medical Academy   Elena V. Zagaynova   Mikhail Y. Kirillin

  10. Choroidal imaging in inherited retinal disease using the technique of enhanced depth imaging optical coherence tomography

    Explore Article SpringerLink Home (Jul 16 2010)

    Choroidal imaging in inherited retinal disease using the technique of enhanced depth imaging optical coherence tomography Abstract Purpose The aim of this study is to image and describe the in vivo choroidal changes in various retinal dystrophies using the technique of enhanced depth imaging (EDI) optical coherence tomography (OCT) and to correlate these findings with the clinical appearance. Associations between choroidal change and genotype, visual acuity and results of retinal electrophysiology are also explored. Design Retrospective observational case series. Methods Twenty patients attending the medical retina clinics at Moorfields Eye Hospital underwent EDI OCT choroidal scans as part of the scanning protocol when they underwent OCT imaging with the Spectralis HRA and OCT. The choroidal images ... (Read Full Article)

    Comment on Article Mentions:   Heidelberg Spectralis   Adnan Tufail   Heidelberg Engineering

  11. Registration of 3D Retinal Optical Coherence Tomography Data and 2D Fundus Images

    Explore Article SpringerLink Home (Jul 5 2010)

    Registration of 3D Retinal Optical Coherence Tomography Data and 2D Fundus Images This paper is focused on multimodal and multidimensional image data registration: the three-dimensional retinal optical coherence tomographic (OCT) data and two-dimensional color images of fundus. The registration of these two modalities is not common in retinal image processing, but it might help to remove the moving artifacts in OCT and correct the true positions of acquired OCT scans on retina. The proposed framework consists of three steps: global dataset pre-registration, preprocessing and OCT to fundus image registration. Two alternating registration criteria are used in the main step due to changing spatial image properties. Three-parametric spatial transformation (shift and scale) for ... (Read Full Article)

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  12. Intravascular Characterization of Vulnerable Coronary Plaque

    Explore Article SpringerLink Home (Jul 1 2010)

    Intravascular Characterization of Vulnerable Coronary Plaque Acute coronary syndromes result from rupture of macrophage-rich, inflamed thin-capped fibroatheroma with superimposed thrombus formation. Ruptured plaques are felt to arise from precursor “vulnerable” lesions that are presumed to be at high risk of disruption. Observations now document that many patients with ACS harbor multiple complex unstable plaques, supporting the concept that plaque instability is not merely a local vascular accident, but instead reflects more systemic pathophysiologic processes. The recognition of the ubiquity of substantial but nonflow limiting lesions that may serve as the fodder for subsequent plaque rupture has resulted in a paradigm shift in thinking about the pathophysiology ... (Read Full Article)

    Comment on Article Mentions:   Massachusetts General Hospital

  13. Optical Coherence Tomography Imaging for Diabetic Retinopathy and Macular Edema

    Explore Article SpringerLink Home (Jun 17 2010)

    Optical Coherence Tomography Imaging for Diabetic Retinopathy and Macular Edema Abstract Optical coherence tomography (OCT) is a noninvasive imaging modality that uses low-coherent interferometry to visualize an optical cross-section of biological tissues. Over the past two decades, the ability to perform OCT imaging of the neural retina has afforded clinicians and researchers a highly reproducible method of diagnosing and following diabetic macular edema (DME) that compares favorably to other methods of DME assessment such as clinical examination and fundus photography. Although central subfield mean thickness has been the OCT parameter most commonly used to evaluate DME in clinical research trials, OCT also allows evaluation of morphologic changes that occur in ... (Read Full Article)

    Comment on Article Mentions:   Harvard University   Optovue   Heidelberg Engineering

  14. Optical Coherence Tomography in Assessing Plaque Characteristics

    Explore Article SpringerLink Home (Jun 9 2010)

    Optical Coherence Tomography in Assessing Plaque Characteristics Abstract Optical coherence tomography (OCT), a new imaging modality, has shown a superior ability in detecting and distinguishing different types of plaques (fibrous, fibrocalcific, and lipid-rich plaques), in visualizing of vascular microstructures such as intraluminal thrombi, vascular dissection, and structure of restenotic tissues, and finally in identifying vulnerable plaques, otherwise missed by intravascular ultrasound. However, limitations in the use of OCT such as poor penetration and its attenuation by blood or the clinical relevance of OCT should be clarified through further investigation, and careful attention should be paid to the future studies on OCT. (Read Full Article)

    Comment on Article Mentions:   Yonsei University   Myeong-Ki Hong   LightLab Imaging

  15. Comparative studies of infrared laser and radio-frequency action on in vitro biotissues by the method of polarization sensitive optical coherence tomography

    Explore Article SpringerLink Home (Jun 8 2010)

    Comparative studies of infrared laser and radio-frequency action on in vitro biotissues by the method of polarization sensitive optical coherence tomography We make comparative studies of structural changes of in vitro biotissues subject to the infrared (IR) laser radiation and the radio-frequency field. Noninvasive diagnostics and monitoring of microstructural changes of biological tissues are performed using optical coherent tomography. (Read Full Article)

    Comment on Article Mentions:   Nizhny Novgorod State Medical Academy   Russian Academy of Sciences   Moscow State University

  16. Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement

    Explore Article SpringerLink Home (Jun 7 2010)

    Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement Background Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma has been well-described, but rarely do these lesions demonstrate intraocular involvement. We report a case of conjunctival MALT lymphoma with intraocular involvement and novel spectral-domain ocular coherence tomography (SD-OCT) findings. Patient and methods A 75-year-old woman with biopsy-proven MALT lymphoma of the conjunctiva presented with ipsilateral yellowish diffuse choroidal infiltrates on fundoscopic examination. Choroidal involvement was documented clinically, on ultrasonography, on fluorescein angiography, and by SD-OCT. Treatment consisted of 3 weeks of oral doxycycline and six cycles of systemic chemotherapy with cyclophosphamide, vincristine, prednisone, and rituximab. Results There was no evidence of progression ... (Read Full Article)

    Comment on Article Mentions:   Carl Zeiss Meditec   David Geffen School of Medicine   Zeiss Cirrus HD-OCT

  17. Capillary pressure may predict preclinical changes in the eye

    Explore Article SpringerLink Home (Jun 7 2010)

    Capillary pressure may predict preclinical changes in the eye Abstract Aims/hypothesis Microvascular dysfunction is associated with end-organ damage. Macular oedema is an important component of diabetic retinopathy. Macular thickness can be accurately quantified by optical coherence tomography (OCT), enabling accurate assessment of the macular prior to clinically apparent abnormalities. We investigated whether macular (fovea) thickness in non-diabetic individuals is related to the microvascular variables controlling fluid filtration across a blood vessel wall, in particular capillary pressure and the microvascular filtration capacity (Kf). Methods We recruited 50 non-diabetic individuals (25 men, 25 women; age range: 26–78 years; BMI range: 20–46 kg/m2). Fovea thickness was assessed by OCT. Microvascular assessments included: ... (Read Full Article)

    Comment on Article Mentions:   Carl Zeiss Meditec   Zeiss Stratus OCT

  18. Optical coherence tomography as an accurate inspection and quality evaluation technique in paper industry

    Explore Article SpringerLink Home (Jun 4 2010)

    Optical coherence tomography as an accurate inspection and quality evaluation technique in paper industry Optical coherence tomography (OCT), a technique for the noninvasive imaging of turbid media, based on low-coherence interferometry, was originally developed for the imaging of biological tissues. Since the development of the technique, most of its applications have been related to the area of biomedicine. However, from early stages, the vertical resolution of the technique has already been improved to a submicron scale. This enables new possibilities and applications. This article presents the possible applications of OCT in paper industry, where submicron or at least a resolution close to one micron is required. This requirement comes from the layered structure of ... (Read Full Article)

    Comment on Article Mentions:   Risto A. Myllylä   University of Oulu   Erkki Alarousu

  19. Optical coherence tomography as a method of quality inspection for printed electronics products

    Explore Article SpringerLink Home (Jun 4 2010)

    Optical coherence tomography as a method of quality inspection for printed electronics products Application of time domain, ultra high resolution optical coherence tomography (UHR-OCT) in printed electronics products’ quality inspection is demonstrated. Presented study was done using experimental UHR-OCT device based on a Kerr-lens mode locked Ti:sapphire femtosecond laser, photonic crystal fibre and modified, free-space Michelson interferometer. Possibilities of the technique are demonstrated by analysis of an RF antenna—example of printed electronics products. Measurements were done with submicron axial resolution, offered by UHR-OCT system developed in our laboratory. Such high resolution is necessary due to the thickness of material layers used in printed electronics. In addition to tomography imaging, numerical results were compared ... (Read Full Article)

    Comment on Article Mentions:   Risto A. Myllylä   University of Oulu   Erkki Alarousu

  20. Early histological alteration of the retina following photocoagulation treatment in diabetic retinopathy as measured by spectral domain optical coherence tomography

    Explore Article SpringerLink Home (May 28 2010)

    Early histological alteration of the retina following photocoagulation treatment in diabetic retinopathy as measured by spectral domain optical coherence tomography Abstract Purpose To investigate the earliest histological changes of the retina after laser treatment of diabetic retinopathy by using Spectral domain optical coherence tomography (SD-OCT, Heidelberg Engineering, Heidelberg, Germany). Methods This study examined 320 laser burns from 16 eyes of 12 patients with early severe non-proliferative diabetic retinopathy (NPDR) that underwent laser photocoagulation according to the protocol which the Early Treatment Diabetic Retinopathy Study (ETDRS) recommended. SD-OCT scan was performed before the laser treatment, then 1 hour, 24 hours, 48 hours, 72 hours and 1 week after treatment. The main outcome measure was thickness change in outer retina (OR) in ... (Read Full Article)

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  21. Cirrus OCT versus Spectralis OCT: differences in segmentation in fibrovascular pigment epithelial detachment

    Explore Article SpringerLink Home (May 22 2010)

    Cirrus OCT versus Spectralis OCT: differences in segmentation in fibrovascular pigment epithelial detachment Abstract Background Automatically measurements of retinal thickness by optical coherence tomography (OCT) facilitate the assessment of various retinal diseases.The aim of this retrospective study was to report macular thickness measurements in eyes with vascular pigment epithelial detachment (PED) due to age-related macular degeneration (AMD) by using two different commercially available spectral domain (SD) OCT instruments and to consequently point out differences in their algorithm software.systems. Methods OCT images of patients with vascular PED due to AMD, obtained with Cirrus and Spectralis OCT, were retrospectively analyzed. Main objectives were to observe differences in central retinal thickness (CRT) values and failures in ... (Read Full Article)

    Comment on Article Mentions:   Heidelberg Spectralis   Susanne Binder   Ludwig Boltzmann Institute

  22. Design, Optimization and Characterisation of Polymeric Microneedle Arrays Prepared by a Novel Laser-Based Micromoulding Technique

    Explore Article SpringerLink Home (May 19 2010)

    Design, Optimization and Characterisation of Polymeric Microneedle Arrays Prepared by a Novel Laser-Based Micromoulding Technique Purpose Design and evaluation of a novel laser-based method for micromoulding of microneedle arrays from polymeric materials under ambient conditions. The aim of this study was to optimise polymeric composition and assess the performance of microneedledevices that possess different geometries. Methods A range of microneedle geometries was engineered into silicone micromoulds, and their physicochemical features were subsequently characterised. Results Microneedles micromoulded from 20% w/w aqueous blends of the mucoadhesive copolymer Gantrez® AN-139 were surprisingly found to possess superior physical strength than those produced from commonly used pharma polymers. Gantrez® AN-139 microneedles, 600 μm and 900 μm in height, penetrated neonatal ... (Read Full Article)

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  23. Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography

    Explore Article SpringerLink Home (May 15 2010)

    Velocity Variation Assessment of Red Blood Cell Aggregation with Spectral Domain Doppler Optical Coherence Tomography We propose spectral domain Doppler optical coherence tomography (SD-D-OCT) to qualitatively measure red blood cell aggregation. Variance/standard deviation (SD) of the Doppler frequency spectrum in Doppler variance imaging of flowing blood under shearing conditions was developed as a new aggregation index. In in vitro microchannel-flow experiments, porcine blood at various hematocrits with aggregation characteristics induced by dextran 500 or at the presence of plasma fibrinogen was measured by a SD-D-OCT system with a spectrum centered at 1310 nm. The effects of shear rate, hematocrit, aggregation level on the SD values were investigated. The results demonstrate that Doppler variance imaging using ... (Read Full Article)

    Comment on Article Mentions:   Zhongping Chen   UC Irvine   Lingfeng Yu

  24. In Vivo, In Situ Imaging of Microneedle Insertion into the Skin of Human Volunteers Using Optical Coherence Tomography

    Explore Article SpringerLink Home (May 13 2010)

    In Vivo, In Situ Imaging of Microneedle Insertion into the Skin of Human Volunteers Using Optical Coherence Tomography Purpose To gather sub-surface in situ images of microneedle-treated human skin, in vivo, using optical coherence tomography (OCT). This is the first study to utilise OCT to investigate the architectural changes that are induced in skin following microneedle application. Methods Steel, silicon and polymer microneedle devices, with different microneedle arrangements and morphologies, were applied to two anatomical sites in human volunteers following appropriate ethical approval. A state-of-the-art ultrahigh resolution OCT imaging system operating at 800 nm wavelength and <3 µm effective axial resolution was used to visualise the microneedle-treated area during insertion and/or following removal of the device, without any ... (Read Full Article)

    Comment on Article Mentions:   Wolfgang Drexler   Cardiff University   Medical University of Vienna

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