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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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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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 ...

Purpose To compare optical coherence tomography (OCT) images obtained with swept-source OCT (SS-OCT) and spectral domain OCT (SD-OCT) in pathological myopia. Methods This is a comparative observational cases series. Five patients with pathological myopia underwent SD-OCT and SS-OCT imaging. SS-OCT was performed using a prototype system (Topcon Medical Systems). SD-OCT was performed using enhanced depth imaging on the Heidelberg Spectralis OCT. The closest corresponding scans from the central subfield were compared. Results Eight eyes of five patients with pathological myopia were included (mean spherical equivalent: −16.00±4.70   D). Overall, SS-OCT better visualized retino-choroidal structures. The choroid, inner segment ...

Objective To assess the macular retina and choroidal thickness change in patients with obstructive sleep apnea-hypopnea syndrome (OSAS) with no significant symptoms and pathological changes in the fundus using spectral domain-optical coherence tomography. Methods This prospective, observational case–control study consisted of 53 eyes of 53 patients with OSAS and 12 eyes of 12 age-matched controls. Macular and choroidal thicknesses were measured by optical coherence tomography. Results The foveal and nasal macular thicknesses were significantly different between four groups (P = 0.001, P = 0.016). The foveal thickness of the control group was significantly thinner than that of the severe ...

Purpose To evaluate the ability of frequency domain-optical coherence tomography (FD-OCT)-measured macular thickness parameters to differentiate between eyes with resolved chronic papilledema and healthy eyes and to evaluate the correlation between FD-OCT measures and visual field (VF) loss on standard automated perimetry (SAP). Methods Fifty-two eyes from 29 patients suffering from pseudotumor cerebri syndrome (PTC) and 62 eyes from 31 normal controls underwent FD-OCT scanning and ophthalmic evaluation including VF with SAP. All patients had previously been submitted to treatment of PTC and had clinically resolved papilledema and stable VF for at least 6 months before the study. Macular ...

Purpose To describe the anterior segment optical coherence tomography (AS-OCT) characteristics of patients with ocular manifestations of mucopolysaccharidoses type I (Hurler), II (Hunter), and VI (Maroteaux–Lamy). Methods Prospective, observational study of nine consecutive patients with variants of mucopolysaccharidosis (MPS) attending the Paediatric Ophthalmology service at Manchester Royal Eye Hospital, UK. All patients underwent Visante AS-OCT imaging as part of their ophthalmic assessment. Results Ocular involvement tended to be symmetrical. Angle-to-angle distance was significantly lower in MPS VI than in MPS I (P = 0.04). Anterior chamber depth, angle opening distance, trabecular-iris space area, and scleral spur angle tended to ...

Purpose To evaluate the morphological and functional changes following intravitreal Ozurdex (dexamethasone implant) injections in patients with macular oedema (MO) secondary to retinal vascular diseases. Design This is a single centre, exploratory phase III, prospective, open-label clinical study. Methods Thirty patients with MO secondary to retinal vascular disorders underwent assessments for best corrected visual acuity, contrast sensitivity, microperimetry, chromatic sensitivity, macular thickness, and morphology using spectral domain optical coherence tomography (SD-OCT) and fluorescein angiography at baseline. They were treated with intravitreal Ozurdex at baseline and monitored monthly with visual acuity and SD-OCT assessments up to 36 weeks. Re-treatment was permitted ...

In Ireland, parts of England and other areas of Europe there are thousands of artworks that were fashioned from rocks during the Neolithic period and the Bronze Age. Threatened by degradation, such cultural heritage attracts scientists and volunteer citizens to ensure its preservation. The tools that researchers have devised to help in this task are themselves creative. In one project, biogeochemists and geomorphologists have developed non-invasive methods that enable researchers and citizens to monitor and mitigate decay. Scientists interested in protecting historic collections are determining how climate change will affect the rates of chemical degradation of paper and silk, pest ...

Purpose To evaluate the deeper structures of the optic nerve and to analyze the shape of eyes with tilted disc syndrome (TDS) by swept-source optical coherence tomography (OCT) and three-dimensional magnetic resonance imaging (3D MRI). Methods The medical records of 54 eyes of 36 patients with TDS were reviewed. The patients with TDS and high myopia were analyzed separately from those without high myopia. All the eyes were examined with a swept-source OCT, and 22 of the eyes were examined by 3D MRI. Results A total of 38 eyes of 29 patients were highly myopic and 16 eyes of 15 ...

Purpose To report optical coherence tomography (OCT) findings in order to detect subclinical alterations of the afferent visual pathways in spinocerebellar ataxia 3 (SCA-3). Patients and methods Nine genetically confirmed patients (18 eyes) were evaluated with a complete ophthalmologic examination including visual acuity, colour vision, visual field test, and retinal nerve fibre layer (RNFL) and macular thickness with OCT Cirrus HD. A neurological examination was performed and the Scale for the Assessment and Rating of Ataxia (SARA score) was determined in all patients. Results The mean RNFL thickness was 77.39 microns, standard deviation (SD) was ±5.93. In 15 ...

As capillaries exhibit heterogeneous and fluctuating dynamics even during baseline, a technique measuring red blood cell (RBC) speed and flux over many capillaries at the same time is needed. Here, we report that optical coherence tomography can capture individual RBC passage simultaneously over many capillaries located at different depths. Further, we demonstrate the ability to quantify RBC speed, flux, and linear density. This technique will provide a means to monitor microvascular flow dynamics over many capillaries at different depths at the same time.

Optical coherence tomography (OCT) may revolutionize fundamental investigation and clinical management of age-related macular degeneration and other eye diseases. However, quantitative OCT interpretation is hampered due to uncertain sub-cellular correlates of reflectivity in the retinal pigment epithelium (RPE) and photoreceptor. The purpose of this study was twofold: 1) to test OCT correlates in the RPE, and 2) to demonstrate the feasibility of longitudinal OCT monitoring of sub-cellular RPE dynamics. A high resolution OCT was constructed to achieve dynamic imaging of frog eyes, in which light-driven translocation of RPE melanosomes occurred within the RPE cell body and apical processes. Comparative histological ...

Aims To examine the impact of manual vs automated disc margin delineation on optic nerve head (ONH) and retinal nerve fiber layer (RNFL) parameters using spectral-domain optical coherence tomography (SDOCT). Methods A prospective cohort study consisting of normal, glaucoma suspect (GS) and glaucoma patients who underwent ONH and RNFL measurements using SDOCT technology (RTVue; Optovue Inc.). The retinal pigment epithelium / Bruch’s membrane (RPE / BM) complex end points were automatically determined first, and were manually redefined subsequently. Analysis of variance, coefficient of variation (COV), concordance correlation coefficient (CCC), and Bland–Altman plots were used for the analyses. Results Ninety-nine eyes ...

Ultrafast lasers have a crucial function in many fields of science; however, up to now, high-energy pulses directly from compact, efficient and low-power semiconductor lasers are not available. Therefore, we introduce a new approach based on temporal compression of the continuous-wave, wavelength-swept output of Fourier domain mode-locked lasers, where a narrowband optical filter is tuned synchronously to the round-trip time of light in a kilometre-long laser cavity. So far, these rapidly swept lasers enabled orders-of-magnitude speed increase in optical coherence tomography. Here we report on the generation of ~60-70 ps pulses at 390 kHz repetition rate. As energy is stored ...