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    1. A combined method to quantify the retinal metabolic rate of oxygen using photoacoustic ophthalmoscopy and optical coherence tomography

      A combined method to quantify the retinal metabolic rate of oxygen using photoacoustic ophthalmoscopy and optical coherence tomography

      Quantitatively determining physiological parameters at a microscopic level in the retina furthers the understanding of the molecular pathways of blinding diseases, such as diabetic retinopathy and glaucoma. An essential parameter, which has yet to be quantified noninvasively, is the retinal oxygen metabolic rate (rMRO 2 ). Quantifying rMRO 2 is challenging because two parameters, the blood flow rate and hemoglobin oxygen saturation (sO 2 ), must be measured together. We combined photoacoustic ophthalmoscopy (PAOM) with spectral domain-optical coherence tomography (SD-OCT) to tackle this challenge, in which PAOM measured the sO 2 and SD-OCT mapped the blood flow rate. We tested the integrated ...

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    2. Matching human pathology is essential for validating OCT imaging to detect high-risk plaques

      Matching human pathology is essential for validating OCT imaging to detect high-risk plaques

      We thank Mark Brezinski for his Correspondence ( Capabilities, limitations, and misconceptions of using OCT to assess vulnerable plaques . Nat. Rev. Cardiol. doi:10.1038/nrcardio.2014.62-c1 ) 1 on our Review ( Clinical classification of plaque morphology in coronary disease . Nat. Rev. Cardiol. 11 , 379 – 389 ; 2014 ), 2 and for his comments and clarifications. We agree that the phenomenon

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    3. Evaluation of choroidal thickness using spectral-domain optical coherence tomography in migraine patients during acute migraine attacks: a comparative stud

      Evaluation of choroidal thickness using spectral-domain optical coherence tomography in migraine patients during acute migraine attacks: a comparative stud

      Purpose The purpose of this study was to assess choroidal thickness in migraine patients during acute migraine attacks and compare them with healthy controls, using spectral domain optical coherence tomography (OCT). Patients and methods In this prospective case–control study, choroidal thicknesses of 46 migraine patients during acute migraine attacks and 46 age- and sex-matched healthy subjects were measured using a high-speed, high-resolution frequency domain-OCT device. All patients underwent a complete ophthalmic examination before the measurements. OCT measurements were taken at the same time of day (0900 hours), in order to minimize the effects of diurnal variation. Results There was ...

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    4. Capabilities, limitations, and misconceptions of using OCT to assess vulnerable plaques

      Capabilities, limitations, and misconceptions of using OCT to assess vulnerable plaques

      Serious concerns exist about the Review by Otsuka et al . (Clinical classification of plaque morphology in coronary disease. Nat. Rev. Cardiol. 11, 379–389; 2014 ), 1 some of which are discussed in this Correspondence. The concerns are predominately about the authors' understanding of the principles and application of optical coherence tomography (OCT),

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    5. Parametric spectro-temporal analyzer (PASTA) for real-time optical spectrum observation

      Parametric spectro-temporal analyzer (PASTA) for real-time optical spectrum observation

      Real-time optical spectrum analysis is an essential tool in observing ultrafast phenomena, such as the dynamic monitoring of spectrum evolution. However, conventional method such as optical spectrum analyzers disperse the spectrum in space and allocate it in time sequence by mechanical rotation of a grating, so are incapable of operating at high speed. A more recent method all-optically stretches the spectrum in time domain, but is limited by the allowable input condition. In view of these constraints, here we present a real-time spectrum analyzer called parametric spectro-temporal analyzer (PASTA), which is based on the time-lens focusing mechanism. It achieves a ...

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    6. Optical coherence tomography for the diagnosis of neovascular age-related macular degeneration: a systematic review

      Optical coherence tomography for the diagnosis of neovascular age-related macular degeneration: a systematic review

      The purpose is to study the diagnostic performance of optical coherence tomography (OCT) and alternative diagnostic tests for neovascular age-related macular degeneration (nAMD). Methods employed are as follows:systematic review and meta-analysis; Index test: OCT including time-domain (TD-OCT) and the most recently developed spectral domain (SD-OCT); comparator tests: visual acuity, clinical evaluation (slit lamp), Amsler chart, colour fundus photographs, infra-red reflectance, red-free images / blue reflectance, fundus autofluorescence imaging (FAF), indocyanine green angiography (ICGA), preferential hyperacuity perimetry (PHP), and microperimetry; reference standard: fundus fluorescein angiography. Databases searched included MEDLINE, MEDLINE In Process, EMBASE, Biosis, SCI, the Cochrane Library, DARE, MEDION, and ...

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    7. Multimodal imaging including spectral-domain optical coherence tomography and confocal near-infrared reflectance for characterization of lacquer cracks in highly myopic eyes

      Multimodal imaging including spectral-domain optical coherence tomography and confocal near-infrared reflectance for characterization of lacquer cracks in highly myopic eyes

      Purpose To compare multimodal imaging in detecting lacquer cracks in highly myopic eyes, and to correlate these findings with those of spectral-domain optical coherence tomography (SD-OCT). Methods An observational case series study. Patients with a refractive error worse than −8 diopters and lacquer cracks were recruited. The rates of detection of the lacquer cracks using multimodal imaging including near-infrared reflectance (NIR) imaging, fundus autofluorescence (FAF) imaging, and fluorescence angiography (FA) were compared. The characteristic findings of multimodal imaging were correlated with those of SD-OCT. Results NIR imaging was more sensitive (92.9 % ) in detecting lacquer cracks than either FAF (12 ...

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    8. Influence of choroidal thickness on subfoveal choroidal thickness measurement repeatability using enhanced depth imaging optical coherence tomography

      Influence of choroidal thickness on subfoveal choroidal thickness measurement repeatability using enhanced depth imaging optical coherence tomography

      Purpose To determine the influence of choroidal thickness (CT) and image setting on repeatability of subfoveal choroidal thickness (SFCT) manual measurement using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods This retrospective study included 189 eyes from 189 adults. Two observers (A and B) measured the SFCT from 1   :   1 micron and 1   :   1 pixel images for evaluation of interobserver repeatability. Observer A performed a single additional measurement for intraobserver repeatability. Results The mean age was 45.1±11.1 years. The mean SFCT from 1   :   1 pixel and 1   :   1 micron images were 315.3±89.2 and 312 ...

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    9. Optical coherence tomography: A new strategy to image planarian regeneration

      Optical coherence tomography: A new strategy to image planarian regeneration

      The planarian is widely used as a model for studying tissue regeneration. In this study, we used optical coherence tomography (OCT) for the real-time, high-resolution imaging of planarian tissue regeneration. Five planaria were sliced transversely to produce 5 head and 5 tail fragments. During a 2-week regeneration period, OCT images of the planaria were acquired to analyze the signal attenuation rates, intensity ratios, and image texture features (including contrast, correlation, homogeneity, energy, and entropy) to compare the primitive and regenerated tissues. In the head and tail fragments, the signal attenuation rates of the regenerated fragments decreased from −0.2 dB ...

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    10. Truncated-correlation photothermal coherence tomography for deep subsurface analysis

      Truncated-correlation photothermal coherence tomography for deep subsurface analysis

      Photothermal diffusion-wave imaging is a promising technique for the analysis of a range of media. However, traditional diffusion-wave techniques are limited by the physics of parabolic diffusion and can only produce depth-integrated planar images. Here, we report a depth-resolved photothermal imaging modality, henceforth termed truncated-correlation photothermal coherence tomography (TC-PCT). This enables three-dimensional visualization of subsurface features, which is not possible with known optical or photothermal imaging techniques. Examples include imaging of solids with intricate subsurface structures and discontinuities, such as holes in steel, burn depth profiles in tissues, and the structure of bone. It is compatible with regulations concerning maximum ...

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    11. Comparison of new motorized injector vs manual injector for implantation of foldable intraocular lenses on wound integrity: an ASOCT study

      Comparison of new motorized injector vs manual injector for implantation of foldable intraocular lenses on wound integrity: an ASOCT study

      Purpose To compare intraocular lens implantation using a motorized injector vs standard manual injector through a 2.2-mm clear corneal incision. Methods Patients underwent standard phacoemulsification using a 2.2-mm clear corneal incision. Hydrophobic acrylic aspheric intraocular lens (Acrysof SN60WF intraocular lens (IOL)) was inserted using D cartridge with manual monarch injector or autosert motorized injector. IOL safety, final incision size and wound integrity in terms of anterior and posterior wound gape, and descemet’s membrane detachment were compared between the two groups at post-operative day 1 and at 1 month using Anterior Segment Optical Coherence Tomography. Results The study ...

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    12. The investigation of acute optic neuritis: a review and proposed protocol

      The investigation of acute optic neuritis: a review and proposed protocol

      Optic neuritis is an inflammatory optic neuropathy that affects many patients with multiple sclerosis (MS) at some point during their disease course. Differentiation of acute episodes of MS-associated optic neuritis from other autoimmune and inflammatory optic neuropathies is vital for treatment choice and further patient management, but is not always straightforward. Over the past decade, a number of new imaging, laboratory and electrophysiological techniques have entered the clinical arena. To date, however, no consensus guidelines have been devised to specify how and when these techniques can be most rationally applied for the diagnostic work-up of patients with acute optic neuritis ...

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    13. 25th RCOphth Congress, President's Session paper: 25 years of progress in medical retina

      25th RCOphth Congress, President's Session paper: 25 years of progress in medical retina

      The quarter century since the foundation of the Royal College of Ophthalmologists has coincided with immense change in the subspecialty of medical retina, which has moved from being the province of a few dedicated enthusiasts to being an integral, core part of ophthalmology in every eye department. In age-related macular degeneration, there has been a move away from targeted, destructive laser therapy, dependent on fluorescein angiography to intravitreal injection therapy of anti-growth factor agents, largely guided by optical coherence tomography. As a result of these changes, ophthalmologists have witnessed a marked improvement in visual outcomes for their patients with wet ...

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    14. Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography

      Evaluation of focal choroidal excavation in the macula using swept-source optical coherence tomography

      Purpose To evaluate imaging findings of patients with focal choroidal excavation (FCE) in the macula using swept-source optical coherence tomography (SS-OCT) and correlate it clinically. Methods Prospective observational case series. Eleven consecutive patients (12 eyes) with FCE were described. Data on demographics and clinical presentation were collected and imaging findings (including color photography, fundus autofluorescence imaging, fluorescein angiography, indocyanine green angiography, spectral-domain optical coherence tomography, and SS-OCT) were analyzed. Results The primary diagnosis was epiretinal membrane (two eyes), choroidal neovascularization (one eye), polypoidal choroidal vasculopathy (three eyes), central serous chorioretinopathy (one eye), and dry age-related macular degeneration (two eyes). Eleven ...

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    15. Ophthalmology Research Scientist Opening at Regeneron Inc

      Ophthalmology Research Scientist Opening at Regeneron Inc

      Job Summary and Essential Functions: Known for its scientific and operational excellence, Regeneron is a leading science-based biopharmaceutical company that discovers, invents, develops, manufactures, and commercializes medicines for the treatment of serious medical conditions. Regeneron markets medicines for eye diseases, colorectal cancer, and a rare inflammatory condition and has product candidates in development in other areas of high unmet medical need, including hypercholesterolemia, oncology, rheumatoid arthritis, allergic asthma, and atopic dermatitis. Summary: This individual will be the key internal Ophthalmology Research scientist supporting the design and creation of viral vectors for genetic manipulation of experimental animals for the group. They ...

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    16. Imaging single chiral nanoparticles in turbid media using circular-polarization optical coherence microscopy

      Imaging single chiral nanoparticles in turbid media using circular-polarization optical coherence microscopy

      Optical coherence tomography (OCT) is a widely used structural imaging method. However, it has limited use in molecular imaging due to the lack of an effective contrast mechanism. Gold nanoparticles have been widely used as molecular probes for optical microcopy based on Surface Plasmon Resonance (SPR). Unfortunately, the SPR enhanced backscattering from nanoparticles is still relatively weak compared with the background signal from microscopic structures in biological tissues when imaged with OCT. Consequently, it is extremely challenging to perform OCT imaging of conventional nanoparticles in thick tissues with sensitivity comparable to that of fluorescence imaging. We have discovered and demonstrated ...

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    17. Clinical classification of plaque morphology in coronary disease

      Clinical classification of plaque morphology in coronary disease

      In published post-mortem pathological studies, more than two-thirds of acute coronary events are associated with the rupture of lipid-rich, voluminous, and outwardly remodelled plaques covered by attenuated and inflamed fibrous caps in the proximal part of coronary arteries. Superficial erosion of the plaques is responsible for most of the remaining events; the eroded plaques usually do not demonstrate much lipid burden, do not have thin fibrous caps, are not positively remodelled, and are not critically occlusive. Both noninvasive and invasive imaging studies have been performed to clinically define the plaque characteristics in acute coronary syndromes in an attempt to identify ...

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    18. Influence of image compression on the interpretation of spectral-domain optical coherence tomography in exudative age-related macular degeneration

      Influence of image compression on the interpretation of spectral-domain optical coherence tomography in exudative age-related macular degeneration

      Purpose To evaluate the effect of image compression of spectral-domain optical coherence tomography (OCT) images in the examination of eyes with exudative age-related macular degeneration (AMD). Methods Thirty eyes from 30 patients who were diagnosed with exudative AMD were included in this retrospective observational case series. The horizontal OCT scans centered at the center of the fovea were conducted using spectral-domain OCT. The images were exported to Tag Image File Format (TIFF) and 100, 75, 50, 25 and 10 % quality of Joint Photographic Experts Group (JPEG) format. OCT images were taken before and after intravitreal ranibizumab injections, and after relapse ...

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    19. Reliability and validity of Cirrus and Spectralis optical coherence tomography for detecting retinal atrophy in Alzheimer’s disease

      Reliability and validity of Cirrus and Spectralis optical coherence tomography for detecting retinal atrophy in Alzheimer’s disease

      Background To evaluate and compare the ability of two Fourier-domain optical coherence tomography (OCT) devices to detect retinal and retinal nerve fibre layer (RNFL) atrophy in patients with Alzheimer’s disease (AD) compared with healthy subjects; to test the intra-session reliability of two OCT devices in AD patients and healthy subjects. Methods AD patients (n = 75) and age-matched healthy subjects (n = 75) underwent three Macular Cube 200 × 200 protocols using the Cirrus and Spectralis OCT devices and three 360° circular scans centred on the optic disc using the Cirrus OCT device, the classic glaucoma application, and the new Nsite Axonal ...

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    20. Association between cystoid spaces on indocyanine green hyperfluorescence and optical coherence tomography after vitrectomy for diabetic macular oedema

      Association between cystoid spaces on indocyanine green hyperfluorescence and optical coherence tomography after vitrectomy for diabetic macular oedema

      Purpose To study retrospectively the characteristics of residual indocyanine green (ICG) fluorescence after ICG-assisted vitrectomy and the association with spectral-domain optical coherence tomography (SD-OCT) findings in diabetic macular oedema (DMO). Methods Thirteen consecutive eyes of 12 patients for whom fundus near-infrared fluorescence and 20° retinal sectional images were obtained using HRA2 and Spectralis OCT, respectively, 5 days after vitrectomy combined with ICG-assisted inner limiting membrane peeling for DMO. The relationship between the characteristics of the ICG hyperfluorescence and the cystoid spaces in the outer plexiform layer (OPL) on SD-OCT images was evaluated. Results A total of 390 well-demarcated areas of ...

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