Objective: To measure anterior chamber (AC) width and other dimensions relevant to the sizing of phakic intraocular lenses (IOLs) with a high-speed optical coherence tomography (OCT) system. Design:Cross-sectional observational study. Participants: Both eyes of 20 normal volunteers.Methods: A novel high-speed (4000 axial scans/second) OCT prototype was developed for anterior segment scanning. The system uses long wavelength (1310 nm) for deeper angle penetration, rectangular scanning for undistorted imaging, and short image acquisition time (0.125 seconds) to reduce motion error. Three horizontal cross-sectional OCT images (15.5 mm wide and 6 mm deep) of the anterior segment were obtained from each eye with real-time image display to guide centration on the corneal apex. Image processing software was developed to correct for image warping resulting from index transitions. Anterior chamber dimensions were measured using computer calipers by 3 expert raters (ophthalmologists). Analysis of variance was used to determine interrater, interimage, right versus left eye, and intersubject standard deviation (SD) of OCT measurements. Main Outcome Measures:Anterior chamber width (recess to recess), AC depth, and crystalline lens vault as measured by OCT; external white-to-white (WTW) corneal diameter (CD) as measured by Holladay-Godwin gauge. Results:The mean AC width was 12.53±0.47 mm (intereye SD), and the mean corneal diameter was 11.78±0.57 mm. Optical coherence tomography measurement of AC width has good repeatability from image to image (SD, 0.134 mm), but there was significant difference between raters (SD, 0.215 mm). Estimation of AC width from WTW CD by linear regression was relatively inaccurate (residual SD, 0.41 mm). The mean AC depth was 2.99±0.323 mm (intereye SD), with

Transforming growth factor b (TGF-b) is an abundant bone matrix protein that influences osteoblast and osteoclast interactions to control bone remodeling. As such, TGF-b represents an obvious pharmacologic target with the potential to regulate both bone formation and resorption to improve bone volume and strength. To investigate the skeletal effect of TGF-b inhibition in vivo, we used an antibody (1D11) specifically directed at all three isoforms of TGF-b. Normal mice were treated with 1D11 or control antibody (4 weeks), and cortical and trabecular bone was assessed by micro-computed tomographic (mCT) scanning. Bone volume and cellular distribution were determined by histomorphometric analysis of vertebrae and long bones. Also, whole-bone strength was assessed biomechanically by three-point bend testing, and tissue-level modulus and composition were analyzed by nanoindentation and Raman microspectroscopy, respectively. TGF-b blockade by 1D11 increased bone mineral density (BMD), trabecular thickness, and bone volume by up to 54%, accompanied by elevated osteoblast numbers and decreased osteoclasts. Biomechanical properties of bone also were enhanced significantly by 1D11 treatment, with increased bending strength and tissue-level modulus. In addition, Raman microspectroscopy demonstrated that 1D11-mediated TGF-b inhibition in the bone environment led to an 11% increase in the mineral-to-collagen ratio of trabecular bone. Together these studies demonstrate that neutralizing TGF-b with 1D11 increases osteoblast numbers while simultaneously decreasing active osteoclasts in the marrow, resulting in a profound increase in bone volume and quality, similar to that seen in parathyroid hormone (PTH)-treated rodent studies. ß

BackgroundLack of menstrual knowledge, poor access to sanitary products and a non-facilitating school environment can make it difficult for girls to attend school. In India, interventions have been developed to reduce the burden of menstruation for school girls by government and non-governmental organizations (NGOs). We sought to identify challenges related to menstruation, and facilitators of menstrual management in schools in three states in India.MethodsSurveys were conducted among menstruating school girls in class 8-10 (above 12 years of age) of 43 government schools selected through stratified random sampling in three Indian states (Maharashtra, Chhattisgarh, Tamil Nadu) in 2015. For comparison, ten model schools supported by NGOs or UNICEF with a focussed menstrual hygiene education program were selected purposely in the same states to represent the better-case scenario. We examined awareness about menarche, items used for menstruation, and facilitators on girls’ experience of menstruation in regular schools and compared with model schools. Factors associated with school absence during menstruation were explored using multivariate analysis.FindingsMore girls (mean age 14.1 years) were informed about menstruation before menarche in model schools (56%, n = 492) than in regular schools (36%, n = 2072, P < 0.001). Girls reported menstruation affected school attendance (6% vs 11% in model vs regular schools respectively, P = 0.003) and concentration (40% vs 45%, P = 0.1) and was associated with pain (31% vs 38%, P = 0.004) and fear of stain or smell (11% vs 16%, P = 0.002). About 45% of girls reported using disposable pads in both model and regular schools, but only 55% and 29% of pad-users reported good disposal facilities, respectively (P < 0.001). In multivariate analysis, reported absenteeism during menstruation was significantly lower in Tamil Nadu (adjusted prevalence ratio (APR) 95% confidence interval (CI) = 0.24, 0.14-0.40) and Maharashtra (APR 0.56, CI = 0.40-0.77) compared to Chhattisgarh, and halved in model compared to regular schools (APR 0.50, CI = 0.34-0.73). Pain medication in school (APR 0.71, CI = 0.51-0.97) and use of disposable pads (APR 0.57, CI = 0.42-0.77) were associated with lower absenteeism and inadequate sanitary facilities with higher absenteeism during menstruation.ConclusionsMenstrual hygiene education, accessible sanitary products, pain relief, and adequate sanitary facilities at school would improve the schooling-experience of adolescent girls in India.

Photothermal optical coherence tomography (PT-OCT) is a potentially powerful tool for molecular imaging. Here, we characterize PT-OCT imaging of gold nanorod (GNR) contrast agents in phantoms, and we apply these techniques for in vivo GNR imaging. The PT-OCT signal was compared to the bio-heat equation in phantoms, and in vivo PT-OCT images were acquired from subcutaneous 400 pM GNR Matrigel injections into mice. Experiments revealed that PT-OCT signals varied as predicted by the bio-heat equation, with significant PT-OCT signal increases at 7.5 pM GNR compared to a scattering control (p < 0.01) while imaging in common path configuration. In vivo PT-OCT images demonstrated an appreciable increase in signal in the presence of GNRs compared to controls. Additionally, in vivo PT-OCT GNR signals were spatially distinct from blood vessels imaged with Doppler OCT. We anticipate that the demonstrated in vivo PT-OCT sensitivity to GNR contrast agents is sufficient to image molecular expression in vivo. Therefore, this work demonstrates the translation of PT-OCT to in vivo imaging and represents the next step towards its use as an in vivo molecular imaging tool.

Matrix metalloproteinases (MMPs) are capable of processing certain components of bone tissue, including type 1 collagen, a determinant of the biomechanical properties of bone tissue, and they are expressed by osteoclasts and osteoblasts. Therefore, we posit that MMP activity can affect the ability of bone to resist fracture. To explore this possibility, we determined the architectural, compositional, and biomechanical properties of bones from wild-type (WT), Mmp2 À/À , and Mmp9 À/À female mice at 16 weeks of age. MMP-2 and MMP-9have similar substrates but are expressed primarily by osteoblasts and osteoclasts, respectively. Analysis of the trabecular compartment of the tibia metaphysis by micro-computed tomography (mCT) revealed that these MMPs influence trabecular architecture, not volume. Interestingly, the loss of MMP-9 improved the connectivity density of the trabeculae, whereas the loss of MMP-2 reduced this parameter. Similar differential effects in architecture were observed in the L 5 vertebra, but bone volume fraction was lower for both Mmp2 À/À and Mmp9 À/À mice than for WT mice. The mineralization density and mineral-to-collagen ratio, as determined by mCT and Raman microspectroscopy, were lower in the Mmp2 À/À bones than in WT control bones. Whole-bone strength, as determined by three-point bending or compression testing, and tissue-level modulus and hardness, as determined by nanoindentation, were less for Mmp2 À/À than for WT bones. In contrast, the Mmp9 À/À femurs were less tough with lower postyield deflection (more brittle) than the WT femurs. Taken together, this information reveals that MMPs play a complex role in maintaining bone integrity, with the cell type that expresses the MMP likely being a contributing factor to how the enzyme affects bone quality. ß

We report a dual-modal device capable of sequential acquisition of Raman spectroscopy (RS) and optical coherence tomography (OCT) along a common optical axis. The device enhances application of both RS and OCT by precisely guiding RS acquisition with OCT images while also compensating for the lack of molecular specificity in OCT with the biochemical specificity of RS. We characterize the system performance and demonstrate the capability to identify structurally ambiguous features within an OCT image with RS in a scattering phantom, guide acquisition of RS from a localized malignancy in ex vivo breast tissue, and perform in vivo tissue analysis of a scab.Optical imaging and spectroscopy have both been used to detect disease based on the analysis of tissue microstructure and biochemical composition, yet neither method has demonstrated the spatial sensitivity and rapid data acquisition needed for screening in combination with the high specificity required for reliable multiclass discrimination. Spectroscopy excels at detecting molecular markers of disease with high specificity, while imaging excels in detecting tissue microstructure with high sensitivity. In particular, near-infrared (NIR) Raman spectroscopy (RS) has been used for in vivo detection of cancers in various organs [1]. RS is sensitive to vibrational modes in tissue and produces fingerprint spectra characteristic of specific molecules and their environments, thus realizing unparalleled molecular specificity. A recent comparison of Raman, fluorescence, and diffuse reflectance spectroscopy for breast cancer detection demonstrated the superior specificity of RS in classifying disease [2]. The weak nature of RS requires integration times of 3-30 s, limiting the technique to point measurements and motivating the need for image guidance to improve sampling accuracy. A combined confocal microscopy-confocal RS device was developed to guide RS acquisition with images of tissue microstructure [3], but confocal imaging depth in epithelial tissues is limited to 250 ≈µm and the transverse field-of-view (FOV) is limited to ≈500 µm. Combining the molecular specificity of RS with an imaging method that has increased depth and larger FOV will yield a valuable tool for the early detection of disease.Optical coherence tomography (OCT) can image over larger transverse areas of tissue (>5 mm) with micrometer scale resolution, real-time speed, and sensitivity to microstructural features

The fracture resistance of bone arises from the composition, orientation, and distribution of the primary constituents at each hierarchical level of organization. Therefore, to establish the relevance of Raman Spectroscopy (RS) in identifying differences between strong or tough bone and weak or brittle bone, we investigated whether Raman-derived properties could explain the variance in biomechanical properties at both the whole bone and the tissue-level, and do so independently of traditional measurements of mineralization. We harvested femurs from wild-type mice and mice lacking matrix metalloproteinase 2 because the mutant mice have a known reduction in mineralization. Next, RS quantified compositional properties directly from the intact diaphysis followed by micro-computed tomography to quantify mineralization density (Ct.TMD). Correlations were then tested for significance between these properties and the biomechanical properties as determined by the three point bending test on the same femurs. Harvested tibia were embedded in plastic, sectioned transversely, and polished in order to acquire average Raman properties per specimen that were then correlated with average nanoindentation properties per specimen. Dividing the ν 1 phosphate by the proline peak intensity provided the strongest correlation between the mineral-to-collagen ratio and the biomechanical properties (whole bone modulus, strength and post-yield deflection plus nanoindentation modulus). Moreover, the linear combination of ν 1 phosphate/proline and Ct.TMD provided the best explanation of the variance in Correspondence: Jeffry S. Nyman, Vanderbilt Orthopaedic Institute, Medical Center East, South Tower, Suite 4200, Nashville, TN, 37232, Tel: (615) 936-6296, Fax: (615) 936-0117, jeffry.s.nyman@vanderbilt.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. CONFLICT OF INTEREST STATEMENTNone of the authors have a conflict of interest related to the research described in this manuscript. The study sponsor had no involvement in the study design, in the collection of data, and the subsequent analysis and interpretation of the results. strength between the genotypes, and it alone was the best explanatory variable for brittleness. Causal relationships between Raman and fracture resistance need to be investigated, but Raman has the potential to assess fracture risk. NIH Public Access

The full range of fracture risk determinants arise from each hierarchical level comprising the organization of bone. Raman spectroscopy is one tool capable of characterizing the collagen and mineral phases at a near sub-micron length scale, but the ability of Raman spectra to distinguish compositional differences of bone is not well defined. Therefore, we analyzed multiple Raman peak intensities and peak ratios to characterize their ability to distinguish between the typically less mineralized osteonal tissue and the more mineralized interstitial tissue in intra-cortical human bone. To further assess origins of variance, we collected Raman spectra from embedded specimens and for 2 orientations of cut. Per specimen, Raman peak intensities or ratios were averaged among multiple sites within 5 osteons and 5 neighboring interstitial tissue. The peak ratios of ν1 phosphate (PO4) to Proline or Amide III detected the highest increases of 15.4% or 12.5%, respectively, in composition from osteonal to interstitial tissue. The coefficient of variance (COV) was less than 5% for each as opposed to a COV of ∼8% for the traditional ν1PO4/Amide I, a peak ratio that varied the most between transverse and longitudinal cuts for each tissue type. Although embedding affected Raman peaks, it did not obscure differences in most peak ratios related to mineralization between the 2 tissue types. In studies with limited sample size but sufficient number of Raman spectra per specimen for spatial averaging, ν1PO4/Amide III or ν1PO4/Proline is the Raman property that is most likely to detect a compositional difference between experimental groups.