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Visible‐light optical coherence tomography (vis‐OCT) is a novel noninvasive retinal imaging system that offers improved resolution compared to conventional near‐infrared (NIR) OCT systems. Here, we utilized vis‐OCT to produce fibergrams (vis‐OCTF) for the first time in human patients, enabling en face visualization and precise quantification of hyperreflective dots in the central fovea in two patients. We also directly compare the imaging qualities of conventional vis‐OCT and NIR‐OCT. Vis‐OCT generated a 3 × 3 mm2en face image with an impressive axial resolution of 1.3 μm, whereas NIR‐OCT produced an en face image with a larger field of view (FOV) (9 × 9 mm2) but a lower resolution of 7.0 μm. Moreover, vis‐OCTF unveiled clear images of hyperreflective dots in the fovea of both patients, which were not discernible in the NIR‐OCT en face images. Foveal dots have often been linked to several age‐related and pathological conditions. The high‐resolution images generated by vis‐OCTF enable more precise characterization of changes in retinal sublayers within the central fovea. [ABSTRACT FROM AUTHOR]

A swept-source dual-wavelength photothermal (DWP) optical coherence tomography (OCT) system is demonstrated for quantitative imaging of microvasculature oxygen saturation. DWP-OCT is capable of recording three-dimensional images of tissue and depth-resolved phase variation in response to photothermal excitation. A 1,064-nm OCT probe and 770-nm and 800-nm photothermal excitation beams are combined in a single-mode optical fiber to measure microvasculature hemoglobin oxygen saturation (SO2) levels in phantom blood vessels with a range of blood flow speeds (0 to 17 mm/s). A 50-µm-diameter blood vessel phantom is imaged, and SO2 levels are measured using DWP-OCT and compared with values provided by a commercial oximeter at various blood oxygen concentrations. The influences of blood flow speed and mechanisms of SNR phase degradation on the accuracy of SO2 measurement are identified and investigated. [ABSTRACT FROM AUTHOR]

Background and Objective: The goal of this paper is to perform a comparative study of the capabilities of optical coherence tomography (OCT) and fluorescence spectroscopy for detection of neoplastic processes and malignant tumor borders in the uterine cervix and vulva, and to preliminarily analyze the advisability of using these two methods complementarily.Study Design/Materials and Methods:Using the two methods-fluorescence spectroscopy, which is based on the detection of biochemical changes in tissue, and optical coherence tomography that detects morphologic or structural tissue information-borders of neoplasia in the uterine cervix and vulva were determined. A parallel analysis of optical properties of tissue and histologic material taken from the center of tumor and the OCT-detected boundary was performed; the visual and optically detected borders of the pathological zone were compared. A total of 12 women with neoplasia in the uterine cervix and vulva were enrolled in this study.Results: First results of this study show that an optically detected demarcation line of cervical neoplasia is farther from the tumor focus by an average of 2 mm than a colposcopically determined border. It was verified that the OCT-detected borders morphologically coincided with the real histologic borders. The OCT and fluorescence spectroscopy yielded the same results in only some experiments. In several clinical cases, it was difficult to interpret OCT images (combination with scar changes in the uterine cervix) and fluorescence spectroscopy data (combination with inflammatory changes).Conclusions: Experimental data presented here show the capability of OCT imaging and fluorescence spectroscopy to detect borders of neoplastic processes in the uterine cervix and vulva more accurately than conventional colposcopy. The results of this study provide a rationale for using these optical techniques in combination as complementary objective methods of cancer diagnostics. [ABSTRACT FROM AUTHOR]