Noninvasive skin fluorescence spectroscopy for detection of abnormal glucose tolerance.

The ENGINE study evaluated noninvasive skin fluorescence spectroscopy (SFS) for detection of abnormal glucose tolerance (AGT). The AGT detection performance of SFS was compared to fasting plasma glucose (FPG) and hemoglobin A (A1C). The study was a head-to-head comparison of SFS to FPG and A1C in an at-risk population of 507 subjects, with no prior diagnosis of diabetes, each of whom received a 75 g, two-hour oral glucose tolerance test (OGTT).

Noninvasive skin fluorescence spectroscopy is comparable to hemoglobin A1c and fasting plasma glucose for detection of abnormal glucose tolerance.

Aim: We compare performance of noninvasive skin fluorescence spectroscopy (SFS), fasting plasma glucose (FPG), and hemoglobin A1c (A1C) for detection of abnormal glucose tolerance (AGT).

Methods: The NSEEDS trial evaluated SFS, FPG, and A1C in an at-risk population of 479 previously undiagnosed subjects from nine US centers, each of whom received a 75 g, 2 h oral glucose tolerance test (OGTT). Skin fluorescence spectra were collected and analyzed with SCOUT DS® devices.

Noninvasive optical screening for diabetes.

Background: Advanced glycation end products (AGEs) are implicated in the complications of diabetes. Advanced glycation end products also accumulate in the skin and are sensitive biomarkers for the risk of developing diabetes and related complications. Some AGEs fluoresce and can be measured noninvasively by optical spectroscopy.

Noninvasive type 2 diabetes screening: superior sensitivity to fasting plasma glucose and A1C.

Objective: This study compared the performance of a novel noninvasive technology to fasting plasma glucose (FPG) and A1C tests for detecting undiagnosed diabetes and impaired glucose tolerance.

Research Design And Methods: The design was a head-to-head evaluation in a naïve population. Consented subjects received FPG and A1C tests and an oral glucose tolerance test (OGTT).

Reflectance-based determination of optical properties in highly attenuating tissue.

Accurate data on in vivo tissue optical properties in the ultraviolet A (UVA) to visible (VIS) range are needed to elucidate light propagation effects and to aid in identifying safe exposure limits for biomedical optical spectroscopy. We have performed a preliminary study toward the development of a diffuse reflectance system with maximum fiber separation distance of less than 2.5 mm.

Selective detection of fluorophore layers in turbid media: the role of fiber-optic probe design.

Experimental verification of the ability to alter the sensitivity to fluorophore layers in turbid media by varying illumination-collection geometry is presented. Fiber-optic probes and two-layer, fluorophore-doped, turbid phantoms are used to elucidate the roles of spot size, illumination-collection fiber separation, and probe-sample spacing. Variations in single- and multiple-fiber probe design parameters produce significant changes in the relative sensitivity to sample layers in a manner that agrees with prior computational studies.

In vivo assessment of diabetic lenses using dynamic light scattering.

One of the most threatening aspects of diabetes mellitus is the development of visual impairment. For example, cataracts are 1.6 times more common in people with diabetes than in those without diabetes.

Multiple-fiber probe design for fluorescence spectroscopy in tissue.

The fiber-optic probe is an essential component of many quantitative fluorescence spectroscopy systems, enabling delivery of excitation light and collection of remitted fluorescence in a wide variety of clinical and laboratory situations. However, there is little information available on the role of illumination--collection geometry to guide the design of these components. Therefore we used a Monte Carlo model to investigate the effect of multifiber probe design parameters--numerical aperture, fiber diameter, source--collection fiber separation distance, and fiber-tissue spacer thickness--on light propagation and the origin of detected fluorescence.