The combination of two-photon microscopy (TPM) and optical coherence tomography (OCT) is useful in conducting in-vivo tissue studies, because they provide complementary information regarding tissues. In the present study, we developed a new combined system using separate light sources and scanners for individually optimal imaging conditions. TPM used a Ti-Sapphire laser and provided molecular and cellular information in microscopic tissue regions. Meanwhile, OCT used a wavelength-swept source centered at 1300 nm and provided structural information in larger tissue regions than TPM. The system was designed to do simultaneous imaging by combining light from both sources. TPM and OCT had the field of view values of 300 μm and 800 μm on one side respectively with a 20x objective. TPM had resolutions of 0.47 μm and 2.5 μm in the lateral and axial directions respectively, and an imaging speed of 40 frames/s. OCT had resolutions of 5 μm and 8 μm in lateral and axial directions respectively, a sensitivity of 97dB, and an imaging speed of 0.8 volumes per second. This combined system was tested with simple microsphere specimens, and was then applied to image small intestine and ear tissues of mouse models ex-vivo. Molecular, cellular, and structural information of the tissues were visualized using the proposed combined system.
Skin auto-fluorescence (SAF) has generated broad interest about the prospects for non-invasive advanced glycation end product assessment and its direct interplay with the development of microvascular complications, but clinical application of the existing SAF measuring of non-palmoplantar sites in non-Caucasian subjects with dark skin type is still controversial. Here, we tested the diabetic complication screening performance of a novel SAF measuring system in Asian type 2 diabetes mellitus (T2DM) subjects. A total of 166 Korean patients with T2DM were enrolled in this study and palmoplantar SAF was measured by a newly developed transmission-geometry noninvasive optical system. We found that transmitted SAF values of palmoplantar sites, 1st dorsal interossei muscles of the hand, in a complication group were significantly higher than in a non-complication group while no differences were observed between the two groups in reflected SAF of non-palmoplantar sites. The transmitted SAF values of palmoplantar sites were dramatically increased in subjects with multiple complications and were tightly correlated with the duration of microvascular complications. In conclusion, the SAF measurement in the palmoplantar sites with a non-invasive transmission-geometry optical system provided better microvascular complication screening performance compared to the SAF measurement of non-palmoplantar sites specifically in Asian T2DM subjects.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.