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    1. Early detection of radiation maculopathy using OCTA imaging: a case report

      Early detection of radiation maculopathy using OCTA imaging: a case report

      Objective To report the case of a 62-year-old female treated with proton beam radiotherapy for a choroidal melanoma. Results After irradiation, the patient was followed-up regularly. Although clinical examination and spectral domain optical coherence tomography (OCT) showed no signs of radiation maculopathy, OCT angiography (OCTA) enabled detection of abnormalities (rarefaction of the vessel at both retinal capillary plexuses) probably related to the radiation maculopathy. Conclusion OCTA could help in the early detection of radiation maculopathy. This could be an important tool to monitor patients and discuss earlier treatments.

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    2. Quantitative analysis of photoreceptor layer reflectivity on en-face optical coherence tomography as an estimator of cone density

      Quantitative analysis of photoreceptor layer reflectivity on en-face optical coherence tomography as an estimator of cone density

      Background To investigate whether outer retinal reflectivity on en-face Optical coherence tomography (OCT) can be considered as an estimator of cone density measured in the same area. Methods Forty-one points of comparisons were studied in 9 eyes ( n = 6 patients) presenting maculopathies with various degrees of impairment of the photoreceptor layer. The inner segment ellipsoid zone (EZ), interdigitation zone (IZ), and retinal pigment epithelium (RPE) reflectivity were measured on coronal reconstruction of the photoreceptor layer using homemade dedicated software (Matlab, MathWorks Inc., Natick, USA). The cone metrics were measured in the same perifoveal region of interest using a high-resolution flood ...

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    3. Optical coherence tomography of Bitot’s spot in vitamin A deficiency

      Optical coherence tomography of Bitot’s spot in vitamin A deficiency

      Background Severe vitamin A deficiency can manifest as xerophthalmia in the eyes resulting in clinical features, such as night blindness, conjunctival xerosis, corneal xerosis, corneal ulcers and Bitot’s spots. We present the multimodal imaging results of a patient who underwent an ileocecal resection for Crohn’s disease and presented with nyctalopia and bilateral central scotomas. Method Report of a single case. Results The patient’s best-corrected visual acuity was 20/50 in the right eye and 20/32 in the left eye. Anterior segment examination identified small elevated focal translucent foamy Bitot’s spots on the superficial bulbar conjunctiva ...

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    4. Characteristics of retinal vessels in surgically closed macular hole: an optical coherence tomography angiography study

      Characteristics of retinal vessels in surgically closed macular hole: an optical coherence tomography angiography study

      Purpose The purpose of our study was to investigate characteristics of retinal vessels in eyes with surgically closed macular holes (MH). Methods We included patients who underwent surgery for idiopathic MH and a follow-up examination using optical coherence tomography angiography (OCTA). The area of the foveal avascular zone (FAZ) and retinal vascular densities of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) were calculated on the postoperative OCTA images and compared with those of age-matched normal controls. Results Twenty-eight patients with MH and 28 controls were included. Mean postoperative FAZ areas of SCP and DCP (0.317 ± 0 ...

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      Mentions: Korea University
    5. Determination of Coefficient of Thermal Expansion in High Power GaN-Based Light-Emitting Diodes via Optical Coherent Tomography

      Determination of Coefficient of Thermal Expansion in High Power GaN-Based Light-Emitting Diodes via Optical Coherent Tomography

      One of the most challenging issues when operating a high-power light-emitting diode (LED) is to conduct appropriate packaging materials for the reliable thermal management of the entire device. Generally, the considerable amount of heat produced around the junction area of the LED would transfers to the entire device, and causes thermal expansion in the packaging material. It induces strain inevitably, and hinders the output performances and possible applications of high-power LEDs. The coefficient of thermal expansion (CTE) is a physical quantity that indicates the expansion to which value a material will be upon heating. Therefore, as far as an advancement ...

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    6. Using Optical Coherence Tomography to Identify of Oral Mucosae with 3D-Printing Probe

      Using Optical Coherence Tomography to Identify of Oral Mucosae with 3D-Printing Probe

      Biomedical materials have different optical properties (e.g. absorption) for different wavelengths. Therefore, probing biomedical materials with multiple wavelengths not only can get in-depth understanding of the detected biomedical materials but also can differentiate the detected biomedical materials. To achieve this purpose, in this conference paper, we present our initial results of building up a portable multiple-wavelength biomedical sensing system. At this initial phase, we assembled this kind of system with multiple wavelengths of light sources and photodetectors and preliminarily tested the absorbance of the glucose solutions with different concentrations. The result shows good linearity of the absorbance of the ...

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    7. Mapping diurnal changes in choroidal, Haller’s and Sattler’s layer thickness using 3-dimensional 1060-nm optical coherence tomography

      Mapping diurnal changes in choroidal, Haller’s and Sattler’s layer thickness using 3-dimensional 1060-nm optical coherence tomography

      Purpose To test the significance of diurnal changes in choroidal, Haller’s and Sattler’s layer thickness in healthy subjects using spatial analysis of three-dimensional (3D) 1060-nm optical coherence tomography (OCT) scans. Methods Automatically generated choroidal, Haller’s and Sattler’s layer thickness maps were statistically analyzed for 19 healthy subjects at two time points (8 a.m. and 6 p.m.) that represent the currently proposed ChT peak and nadir. All subjects were imaged by high-speed 1060-nm OCT over a 36° × 36° field of view. Spatial distribution of layer thickness was analyzed using the Early Treatment Diabetic Retinopathy Study ...

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    8. Imaging the event-prone coronary artery plaque

      Imaging the event-prone coronary artery plaque

      Acute coronary events, the dreaded manifestation of coronary atherosclerosis, remain one of the main contributors to mortality and disability in the developed world. The majority of those events are associated with atherosclerotic plaques-related thrombus formation following an acute disruption, that being rupture or erosion, of an event-prone lesion. These historically termed vulnerable plaques have been the target of numerous benchtop and clinical research endeavors, yet to date without solid results that would allow for early identification and potential treatment. Technological leaps in cardiovascular imaging have provided novel insights into the formation and role of the event-prone plaques. From intracoronary optical ...

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    9. Current clinical applications of coronary optical coherence tomography

      Current clinical applications of coronary optical coherence tomography

      Optical coherence tomography (OCT) is an intra-coronary diagnostic technique that provides detailed imagings of blood vessels in the current cardiac catheterization laboratory. The higher resolution of OCT often provides superior delineation of each structure compared with intravascular ultrasound (IVUS), and it can reliably visualize the microstructure of normal and diseased arteries. The capabilities of OCT are well suited for the identification of calcified plaque and neointima formation after stent implantation. It has been reported that OCT-guided percutaneous coronary intervention (PCI) resulted in equivalent clinical and angiographic outcomes in comparison with IVUS-guided PCI. Recently, the three-dimensional reconstruction of OCT and a ...

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    10. Automatic Identification of Intraretinal Cystoid Regions in Optical Coherence Tomography

      Automatic Identification of Intraretinal Cystoid Regions in Optical Coherence Tomography

      Optical Coherence Tomography (OCT) is, nowadays, one of the most referred ophthalmological imaging techniques. OCT imaging offers a window to the eye fundus in a non-invasive way, permitting the inspection of the retinal layers in a cross sectional visualization. For that reason, OCT images are frequently used in the analysis of relevant diseases such as hypertension or diabetes. Among other pathological structures, a correct identification of cystoid regions is a crucial task to achieve an adequate clinical analysis and characterization, as in the case of the analysis of the exudative macular disease. This paper proposes a new methodology for the ...

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    11. Optical coherence tomography angiography in pre-perimetric open-angle glaucoma

      Optical coherence tomography angiography in pre-perimetric open-angle glaucoma

      Purpose To evaluate the diagnostic efficacy of optical coherence tomography (OCT) angiography, in patients with pre-perimetric open-angle glaucoma. Methods Thirty-eight consecutive eyes of 26 patients with pre-perimetric open-angle glaucoma and 48 normal eyes of 32 controls were included in this prospective study. We evaluated OCT angiography, spectral-domain OCT and visual fields parameters. Differences between controls and patients and between OCT angiography parameters and traditional glaucoma measurements were evaluated. Receiver operating characteristic curves for OCT angiography parameters were assessed. Results The flow index ( p = 0.021) and vessel density ( p = 0.001) were significantly lower in pre-perimetric glaucoma eyes versus normal ...

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    12. Microvascular changes after vitrectomy with internal limiting membrane peeling: an optical coherence tomography angiography study

      Microvascular changes after vitrectomy with internal limiting membrane peeling: an optical coherence tomography angiography study

      Purpose To evaluate superficial capillary plexus (SCP) changes occurring after internal limiting membrane (ILM) peeling for the treatment of idiopathic epiretinal membrane (ERM). Methods A total of 15 eyes of 15 patients affected by idiopathic ERM (eight males and seven females; mean age 59.8 ± 9.6 years) were enrolled in the study. Patients were treated with pars plana vitrectomy followed by ERM and ILM peeling. Subjects were evaluated at baseline and at the week-1 and month-1 follow-up visits. At each visit, patients were evaluated with a complete ophthalmologic evaluation, which included imaging with optical coherence tomography angiography. Results Overall ...

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    13. Spectral Domain Optical Coherence Tomography in Macular Disease (Textbook)

      Spectral Domain Optical Coherence Tomography in Macular Disease (Textbook)

      . This book aims to build concepts and create a solid foundation in the field of optical coherence tomography (OCT) for the general ophthalmologists as well as for the resident trainees and fellows. The chapters are written by leading international authorities in a style comprehensible to a broad audience. Numerous clinical pictures and SD-OCT scans help elucidate various clinical entities.OCT is the optical analog of ultrasound imaging and has emerged as a powerful imaging technique that enables non-invasive, in-vivo, high-resolution, cross-sectional imaging in retinal tissue. A new generation spectral domain optical coherence tomography (SD-OCT) technology has now been developed, representing ...

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    14. Automatic Detection of Epiretinal Membrane in OCT Images by Means of Local Luminosity Patterns

      Automatic Detection of Epiretinal Membrane in OCT Images by Means of Local Luminosity Patterns

      This work presents a novel approach for automatic detection of the epiretinal membrane in Optical Coherence Tomography (OCT) images. A tool able to detect this pathology is very valued since it can prevent further ocular damage by doing an early detection. This approach is based in the location of the inner limiting membrane (ILM) layers of the retina. Then, the detected locations are classified using a local-feature based vector in order to determine presence of the membrane. Different tests are run and compared to establish the appropriateness of the approach as well as its practical validity.

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    15. Recent Advances in the Field of Optical Coherence Tomography

      Recent Advances in the Field of Optical Coherence Tomography

      Purpose of Review The scope of this text is to critically review the most important recent advances in the field of optical coherence tomography, both from a clinical, scientific, and technical point of view. Recent Findings In recent years, important steps forward have been put in the field of optimization of PCI (with a focus on optimal sizing of stents and optimization of stent expansion after implantation) and the differentiation and its possible applications of various underlying morphologic characteristics of acute coronary syndrome lesions. Several efforts have been made to elucidate underlying mechanical causes of stent thrombosis, based on optical ...

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    16. Ganglion cell loss in early glaucoma, as assessed by photopic negative response, pattern electroretinogram, and spectral-domain optical coherence tomography

      Ganglion cell loss in early glaucoma, as assessed by photopic negative response, pattern electroretinogram, and spectral-domain optical coherence tomography

      Purpose To evaluate discrimination ability of pattern electroretinography (PERG) and photopic negative response (PhNR) between early glaucoma and healthy controls, and their relationship with structural measurements using spectral-domain optical coherence tomography (SD-OCT). Methods Cross-sectional study with 34 patients with ocular hypertension ( n = 7), suspect glaucoma ( n = 17), and early glaucoma ( n = 10), plus 24 age-matched controls. The following parameters were analyzed: P50 and N95 amplitude of the PERG, PhNR amplitude and PhNR/b-wave ratio, peripapillary retinal and macular nerve fiber layer (NFL) thicknesses, and ganglion cell complex (GCC) thickness. Data from only one eye per individual were included in the ...

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    17. Wire bias in coronary measurement using optical coherence tomography

      Wire bias in coronary measurement using optical coherence tomography

      OCT is widely used for accurate coronary stent sizing; however, the impact of coronary tortuosity or guide wire weight on the accuracy of OCT in assessing coronary dimensions is not known. This study sought to determine whether guide wire properties impact on coronary diameter and length estimation by optical coherence tomography (OCT) in tortuous segments of coronary artery. OCT coronary diameters were determined in selected patients with tortuous arteries before and after removal of a supportive guide wire to obtain unobscured images. In addition, a coronary model was created with lumen diameters of 1.7–4.8 mm. This was ...

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    18. Classification of Fingerprints Captured Using Optical Coherence Tomography

      Classification of Fingerprints Captured Using Optical Coherence Tomography

      We propose a technique for analysis of fingerprints scanned free-air (not pressed against a glass) with Optical Coherence Tomography (OCT). Fingerprints from the surface and subdermal parts of the finger are extracted from a 2 GB volumetric scan in cca. 2 s using our specialized technique and GPU acceleration on GeForce GTX 980. The technique provides fingerprints that perform with promising error rates that demonstrate the potential of the OCT for improved fingerprint identification, as well as its potential for prevention of biometric spoofing (PAD).

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    19. Proposal of a simple optical coherence tomography-based scoring system for progression of age-related macular degeneration

      Proposal of a simple optical coherence tomography-based scoring system for progression of age-related macular degeneration

      Purpose To develop a simple, clinically practical, optical coherence tomography (OCT)-based scoring system for early age-related macular degeneration (AMD) to prognosticate risk for progression to late AMD. Methods We retrospectively reviewed OCT images (512 × 128 macular cube, Cirrus) from 138 patients diagnosed of early AMD in at least one eye and follow-up of at least 12 months. For patients with early AMD in both eyes, only the right eye was chosen as the study eye for longitudinal assessment. Scans were graded on four SD-OCT criteria associated with disease progression in previous studies: drusen volume within a central 3-mm circle ...

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    20. Optical coherence tomography angiography wide-field montage in branch retinal vein occlusion before and after anti-vascular endothelial-derived growth factor injection

      Optical coherence tomography angiography wide-field montage in branch retinal vein occlusion before and after anti-vascular endothelial-derived growth factor injection

      The wide-field montage technique of optical coherence tomography angiography provides good delineation of the improvement in microvascular disturbance associated with branch retinal vein occlusion after treatment with anti-vascular endothelial-derived growth factor injection. It may be further evaluated for the assessment of treatment progress in patients with retinal vein occlusion.

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    21. Optical coherence tomography as a marker of neurodegeneration in patients with Wilson’s disease

      Optical coherence tomography as a marker of neurodegeneration in patients with Wilson’s disease

      Wilson’s disease (WD) is an inherited autosomal recessive disorder that leads to pathological copper accumulation in different organs. Optical coherence tomography (OCT) is proposed as a marker of neurodegeneration in many neurological diseases. Thinning of the total retinal nerve fiber layer (RNFL) and macular thickness (Mth) examined by OCT was detected in patients with WD, especially those with brain magnetic resonance imaging changes. The aim of this study was to evaluate the relationship between OCT parameters and the progression of neurological signs measured by the Unified Wilson’s Disease Rating Scale (UWDRS) in patients with WD. Consecutive patients with ...

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    22. Supercontinuum Generation in a Silicon Nanowire Embedded Photonic Crystal Fiber for Optical Coherence Tomography Applications (Book Chapter)

      Supercontinuum Generation in a Silicon Nanowire Embedded Photonic Crystal Fiber for Optical Coherence Tomography Applications (Book Chapter)

      In this paper, we design a silicon nanowire embedded photonic crystal fiber (SN-PCF) using fully vectorial finite element method. Further, we analyze the various optical properties, namely, waveguide dispersion and nonlinearity by varying the core diameter from 400 to 500 nm for a wide range of wavelengths from 0.8 to 1.7 μm. The proposed structure exhibits a low second (−0.4909 ps 2 /m) and third order (0.6595 10 −3 ps 3 /m) dispersions with very high nonlinearity (1358 W −1 m −1 ) for 480 nm core diameter at 0.8 μm wavelength. Besides, we investigate the ...

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