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71.
Nam Hyun Cho Sang Heun Lee Woonggyu Jung Jeong Hun Jang Jeehyun Kim 《Journal of Korean medical science》2015,30(3):328-335
We report the application of optical coherence tomography (OCT) to the diagnosis and evaluation of otitis media (OM). Whereas conventional diagnostic modalities for OM, including standard and pneumatic otoscopy, are limited to visualizing the surface of the tympanic membrane (TM), OCT effectively reveals the depth-resolved microstructure below the TM with very high spatial resolution, with the potential advantage of its use for diagnosing different types of OM. We examined the use of 840-nm spectral domain-OCT (SD-OCT) clinically, using normal ears and ears with the adhesive and effusion types of OM. Specific features were identified in two-dimensional OCT images of abnormal TMs, compared to images of healthy TMs. Analysis of the A-scan (axial depth scan) identified unique patterns of constituents within the effusions. The OCT images could not only be used to construct a database for the diagnosis and classification of OM but OCT might also represent an upgrade over current otoscopy techniques.
Graphical Abstract
相似文献72.
Purpose
To provide normal macular thickness measurements using Spectral Domain Optical Coherence Tomography (SDOCT, Copernicus, Optopol Technologies, Zawierci, Poland).Methods
Fifty-eight eyes of 58 healthy subjects were included in this prospective study. All subjects had comprehensive ophthalmic examination including best-corrected visual acuity (BCVA). All the subjects underwent Copernicus SDOCT. Central foveal thickness (CFT) and photoreceptor layer (PRL) thickness were measured and expressed as mean and standard deviation. Mean retinal thickness for each of the 9 regions defined in the Early Treatment Diabetic Retinopathy Study was reported. The data were compared with published literature in Indians using Stratus and Spectralis OCTs to assess variation in instrument measurements.Results
The mean CFT in the study sample was 173.8 ± 18.16 microns (131–215 microns) and the mean PRL thickness was 65.48 ± 4.23 microns (56–74 microns). No significant difference (p = 0.148) was found between CFT measured automated (179.28 ± 22 microns) and manually (173.83 ± 18.1 microns). CFT was significantly lower in women (167.62 ± 16.36 microns) compared to men (180.03 ± 18 microns) (p = 0.008). Mean retinal thickness reported in this study was significantly different from published literature using Stratus OCT and Spectralis OCT.Conclusion
We report the normal mean retinal thickness in central 1 mm area to be between 138 and 242 microns in Indian population using Copernicus SDOCT. We suggest that different OCT instruments cannot be used interchangeably for the measurement of macular thickness as they vary in segmentation algorithms. 相似文献73.
Pino Cidad Eugenia González Mónica Asencio Jesús García 《Korean journal of ophthalmology : KJO》2015,29(5):331-335
PurposeTo study the retinal pigment epithelium (RPE) and retinal alterations in chronic central serous chorioretinopathy treated with photodynamic therapy, and its correlation with functional parameters such as best-corrected visual acuity (BCVA) and contrast sensitivity (CS).MethodsRetrospective, noncomparative, consecutive evaluation by optical coherence tomography and its correlation with BCVA and CS in 31 eyes of 26 patients.ResultsIn all affected patients, 88.5% were male with a mean age of 42.9 years. The right eye was involved in 64.5% of cases, bilateral in 19% and 73.9% were hyperopic (spherical refraction between 0 and +5.0 diopters). Of these cases, 51.5% had peri-RPE abnormalities, 17.3% hyperreflective substances at RPE, 19.4% RPE atrophy, 55.3% foveolar atrophy, 3.1% pigment epithelial detachment, 5.2% subretinal fluid persistence, 8.3% fibrin deposits, 68.4% photoreceptor inner and outer segment line interruption and 31.1% external limiting membrane interruption.ConclusionsTime evolution and number of outbreaks were related to the decrease in foveal and chorodial thickness and in those with worse BCVA and CS. RPE abnormalities and atrophy were related to the age of onset of symptoms. Photoreceptor elongation has been correlated with poor BCVA and inner and outer segment line destructuring and interruption with poor CS. 相似文献
74.
Kang Hoon Lee Hee Seung Chin Na Rae Kim Yeon Sung Moon 《Korean journal of ophthalmology : KJO》2015,29(6):396-403
PurposeTo investigate the effects of vitreomacular traction (VMT) on ranibizumab treatment response for neovascular age-related macular degeneration (AMD).MethodsA retrospective review of 85 eyes of 85 patients newly diagnosed with neovascular AMD was conducted. Patients were eligible if they had received more than three consecutive monthly ranibizumab (0.50 mg) treatments and ophthalmic evaluations. Patients were classified into a VMT (+) group or VMT (-) group according to optical coherence tomography imaging. Best corrected visual acuity and central retinal thickness (CRT) measurements were obtained at three and six months after initial injection.ResultsOne month after the third injection, mean visual acuity (VA) increases of 6.36 and 9.87 letters were observed in the VMT (+) and VMT (-) groups, respectively. The corresponding mean CRT values decreased by 70.29 µm and 121.68 µm, respectively. A total 41 eyes were identified as eligible for a subsequent fourth injection; 71.1% of patients (27 eyes) in the VMT (+) group but only 29.8% of patients in the VMT (-) group needed a subsequent fourth injection. Follow-up was extended to six months for 42 of the 85 enrolled patients (49.4%). The trends in VA and optical coherence tomography were found to be maintained at six-month follow-up.ConclusionsVA and CRT appeared to be more improved after ranibizumab treatment in the VMT (-) group compared to the VMT (+) group. VMT might antagonize the effect of ranibizumab treatment in a subpopulation of AMD patients. 相似文献
75.
Mitsuyasu Terashima Hideaki Kaneda Yasuhiro Honda Tetsuro Shimura Atsuko Kodama Maoto Habara Takahiko Suzuki 《Journal of cardiology》2021,77(5):435-443
Both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) play a crucial role in elucidating the pathophysiology of coronary artery disease (CAD) with the goal to improve patient outcomes of medical and/or interventional CAD management. However, no single intravascular imaging technique has been proven to provide complete and detailed evaluation of all CAD lesions due to some limitations. Although sequential use of multiple modalities may sometimes be performed, there may be issues related to risk, time, and cost. To overcome these problems, several hybrids involving dual-probe combined IVUS-OCT catheters have been developed.The aim of this review article is to demonstrate some limitations of stand-alone imaging devices for evaluation of CAD, summarize the advances in hybrid IVUS-OCT imaging devices, discuss the technical challenges, and present the potential value in the clinical setting, especially in patients receiving medical or interventional CAD management. 相似文献
76.
77.
W. Kenneth Ward 《Journal of diabetes science and technology》2007,1(2):201-204
Amperometric sensors for continuous glucose monitoring could prevent acute and chronic complications of diabetes, but research is needed to improve accuracy and stability. In designing sensors, interference from non-glucose analytes can be minimized by use of filtration membranes or electron transfer mediators that allow polarization at low potentials. If oxygen is required for the enzymatic reaction with glucose, then the outer permselective membrane must have substantial oxygen permeability. For this reason, during development of permselective membranes, permeability studies (such as performed by Tipnis and colleagues in this issue) can be used to measure transport of glucose and oxygen and optimize membrane structure. Tipnis and colleagues present a novel biosensor based with separate layers for glucose-oxygen permselectivity, enzymatic conversion, and avoidance of interference. They also address sensor stability, in part by comparing sensor function during ascending vs descending glucose levels. By measuring the difference, they were able to minimize this aspect of instability (hysterisis), which assisted them in selecting a promising permselective membrane based on iron and humic acid. 相似文献
78.
The purpose of this study was to suggest a novel optical flow method to estimate the motion patterns of contrast agents from an ultrasound image. We first recomposed the original image with relative structural and textural parts. We embedded an anisotropic diffusion model into a slightly non-convex total variation-L1 approximation scheme to provide more reliable estimates. An intermediate bilateral filter was adopted after each computation step to prevent over-smoothing effects. Ultrasound data were acquired during continuous injection of contrast agent into a tissue mimicking phantom. The results showed that our method provided robust performance for estimating contrast agent flow patterns. 相似文献
79.
Cell refractive index (RI) is an intrinsic optical parameter that governs the propagation of light (i.e., scattering and absorption) in the cell matrix. The RI of cell is sensitively correlated with its mass distribution and thereby has the capability to provide important insights for diverse biological models. Herein, we review the cell refractive index and the fundamental models for measurement of cell RI, summarize the published RI data of cell and cell organelles and discuss the associated insights. Illustrative applications of cell RI in cell biology are also outlined. Finally, future research trends and applications of cell RI, including novel imaging techniques, reshaping flow cytometry and microfluidic platforms for single cell manipulation are discussed. The rapid technological advances in optical imaging integrated with microfluidic regime seems to enable deeper understanding of subcellular dynamics with high spatio-temporal resolution in real time. 相似文献
80.
This paper presents a 3D endoscopic video system designed to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery. In a comparison of the polarized and electric shutter-type stereo imaging systems, the former was found to be superior in terms of both accuracy and speed for knot-tying and for the loop pass test. The results of our experiments show that the proposed 3D endoscopic system has a sufficiently wide viewing angle and zone for multi-viewing, and that it provides better image quality and more stable optical performance compared with the electric shutter-type. 相似文献