Optical coherence tomography

About: Optical coherence tomography is a research topic. Over the lifetime, 19051 publications have been published within this topic receiving 477433 citations. The topic is also known as: optical coherent tomography.

Three-dimensional endoscopic optical coherence tomography by use of a two-axis microelectromechanical scanning mirror

Abstract: We present a three-dimensional (3D) endoscopic optical coherence tomography (OCT) system based on a dual-axis scanning microelectromechanical system (MEMS) mirror. The diameter of the MEMS mirror was 1.2mm and both axes were capable of scanning greater than 20° with linearity. The endoscopic MEMS probe was integrated with an OCT system and volume images were obtained at a rate of 3frames∕s by means of two-axis lateral scanning combined with an axial scan. In the initial investigations, 3D OCT images of healthy rabbit trachea as well as images of normal and cancerous regions of hamster cheek pouch tissue were obtained.

Optical coherence tomography assisted ophthalmologic surgical microscope

Abstract: Ophthalmologic surgical microscope which is combined internally with an optical coherence tomography ("OCT") apparatus wherein auto-focusing is provided by driving a motorized internal focusing lens of the ophthalmologic surgical microscope with a signal output from the OCT apparatus. An embodiment of the inventive ophthalmologic surgical microscope includes: (a) an optical coherence tomography ("OCT") apparatus; (b) a beamcombiner for internally coupling output from the OCT apparatus into the ophthalmologic surgical microscope; and (c) a motor for moving an internal focusing lens of the ophthalmologic surgical microscope in response to a signal from the OCT apparatus, whereby the ophthalmologic surgical microscope is auto-focused.

Autocalibration of spectral-domain optical coherence tomography spectrometers for in vivo quantitative retinal nerve fiber layer birefringence determination.

Abstract: Accurate wavelength assignment of each spectral element for spectral-domain optical coherence tomography SD-OCT and op- tical frequency domain imaging OFDI is required for proper con- struction of biological tissue cross-sectional images. This becomes more critical for functional extensions of these techniques, especially in polarization-sensitive optical coherence tomography PS-OCT, where incorrect wavelength assignment between the two orthogonal polarization channels leads to polarization artifacts. We present an autocalibration method for wavelength assignment that does not re- quire separate calibration measurements and that can be applied di- rectly on actual data. Removal of the birefringence artifact is demon- strated in a PS-OCT system with picometer accuracy in the relative wavelength assignment, resulting in a residual phase error of 0.25 deg/100 m. We also demonstrate, for the first time, a quanti- tative birefringence map of an in vivo human retinal nerve fiber layer.

Clinical evaluation of simultaneous confocal scanning laser ophthalmoscopy imaging combined with high-resolution, spectral-domain optical coherence tomography

Abstract: Acta Ophthalmol. 2010: 88: 842–849 Abstract. Purpose: To evaluate the clinical relevance of a new diagnostic modality, simultaneous confocal scanning laser ophthalmoscopy (cSLO) and high-speed, high-resolution, spectral-domain optical coherence tomography (OCT), for the visualization of macular pathologies. Methods: OCT images and simultaneous recording of fluorescein angiography, indocyanine green (ICG) angiography, infrared, and blue reflectance (‘red-free’) or fundus autofluorecence (FAF) images were obtained with a novel imaging device (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany). An optically pumped solid-state laser generated the excitation wavelength (488 nm) required for blue reflectance, FAF and fluorescein angiography images. For ICG angiography and infrared imaging, diode laser sources at 790 and 815 nm were used. For OCT, 40 000 A-scans per second were acquired with 7 μm axial and 14 μm lateral optical resolution. The B-scans covering a transversal range of 30° had a scan width up to 1.536 A-scans with a digital lateral resolution of 5 μm/pixel, a scan depth of 1.8 mm with 3.5 μm/pixel digital axial resolution and a scan rate of up to 48 B-scans/second. In addition, volume scans could be obtained at 15, 20 and 30° fields of view. An integrated eye tracking allowed for live averaging of cSLO images as well as OCT B-scans. Results: Early, neovascular and atrophic age-related macular degeneration, macular telangiectasia, retinal arterial, branch vein occlusion and other pathologies were imaged, and cSLO and OCT frames correlated. Fluorescein and ICG angiographic phenomena recorded in cSLO images could be analysed accurately in corresponding OCT cross-sections. Abnormal FAF signals were correlated to alterations at the outer retinal/retinal pigment epithelial cell layer in high-resolution OCT scans. Three-dimensional OCT enabled comprehensive retinal coverage. The imaging software tracked eye movements accurately. Averaging of live B-scans enhanced image quality considerably. Conclusion: The combined cSLO/OCT system allowed for simultaneous recordings of topographic and tomographic images with accurate correlation between the confocal angiograms, FAF images as well as other imaging modes with the OCT scans. The instrument thus provides simultaneous multi-modal imaging of retinal pathologies and disease.

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.