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Correlation between optic nerve head structural parameters and glaucomatous visual field indices
摘要： We examined associations between optic nerve head structural parameters and glaucomatous visual field indices. The study population included patients with glaucomatous optic neuropathy who were evaluated at Aichi Medical University, Nagakute, Aichi, Japan, from October 2010 to January 2011. A total of 57 eyes from 33 patients were assessed. We measured visual field using a Humphrey field analyzer, peripapillary retinal nerve fiber layer thickness (RNFL-T), and Bruch’s membrane opening-minimum rim width (BMO-MRW) using spectral domain optical coherence tomography, and rim area with referring three-dimensional photography. Spearman’s rank correlation coefficients were calculated between the threshold of visual sensitivity or total deviation of visual field and the following five optic nerve head structural parameters: RNFL-T length, BMO-MRW length, rim area, and calculated RNFL-T and BMO-MRW volumes (each length multiplied by rim area). The Akaike information criterion was calculated to determine which structural parameter was the best predictor of each visual field index. Threshold of visual sensitivity had correlation coefficients of 0.23 with global sector of RNFL-T, 0.32 with BMO-MRW, 0.14 with rim area, 0.21 with RNFL-T volume, and 0.26 with BMO-MRW volume. The correlation coefficients for each parameter with total deviation of visual field were 0.22, 0.33, 0.28, 0.36, and 0.37, respectively. The Akaike information criterion of BMO-MRW showed the smallest values in analyses of both threshold of visual sensitivity and total deviation. The present results show that RNFL-T volume and BMO-MRW volume were more strongly correlated with total deviation than BMO-MRW, but BMO-MRW appeared to be the best predictor of the two glaucomatous visual field indices.
关键词： retinal nerve fiber layer thickness,rim area,visual field,glaucoma,spectral domain optical coherence tomography,Bruch’s membrane opening-minimum rim width
更新于2025-09-04 15:30:14
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Influence of complexing agent on the growth of chemically deposited Ni3Pb2S2 thin films
摘要： Ni3Pb2S2 thin films were prepared by chemical bath deposition method. Here, the objective of this research is to investigate the influence of complexing agent on the properties of films.These films were characterized using atomic force microscopy, UV-Visible spectrophotometery and X-ray diffraction. It was found that the increase in the concentration of tartaric acid, film thickness increased, but, the band gap reduced. For the films prepared using 0.1M of tartaric acid, were found uniform and completely covered with the substrates.
关键词： chemical bath deposition,band gap,thin films,thickness
更新于2025-09-04 15:30:14
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Physically-Based Retrieval of Canopy Equivalent Water Thickness Using Hyperspectral Data
摘要： Quantitative equivalent water thickness on canopy level (EWTcanopy) is an important land surface variable and retrieving EWTcanopy from remote sensing has been targeted by many studies. However, the effect of radiative penetration into the canopy has not been fully understood. Therefore, in this study the Beer-Lambert law is applied to inversely determine water content information in the 930 to 1060 nm range of canopy reflectance from measured winter wheat and corn spectra collected in 2015, 2017, and 2018. The spectral model was calibrated using a look-up-table (LUT) of 50,000 PROSPECT spectra. Internal model validation was performed using two leaf optical properties datasets (LOPEX93 and ANGERS). Destructive in-situ measurements of water content were collected separately for leaves, stalks, and fruits. Correlation between measured and modelled water content was most promising for leaves and ears in case of wheat, reaching coefficients of determination (R2) up to 0.72 and relative RMSE (rRMSE) of 26% and in case of corn for the leaf fraction only (R2 = 0.86, rRMSE = 23%). These findings indicate that, depending on the crop type and its structure, different parts of the canopy are observed by optical sensors. The results from the Munich-North-Isar test sites indicated that plant compartment specific EWTcanopy allows us to deduce more information about the physical meaning of model results than from equivalent water thickness on leaf level (EWT) which is upscaled to canopy water content (CWC) by multiplication of the leaf area index (LAI). Therefore, it is suggested to collect EWTcanopy data and corresponding reflectance for different crop types over the entire growing cycle. Nevertheless, the calibrated model proved to be transferable in time and space and thus can be applied for fast and effective retrieval of EWTcanopy in the scope of future hyperspectral satellite missions.
关键词： EnMAP,hyperspectral,spectroscopy,equivalent water thickness,canopy water content,agriculture
更新于2025-09-04 15:30:14
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Characterization of the thickness of the tear film lipid layer using high resolution microscopy
摘要： Interferometry is an optical technique that have been used to quantify the lipid layer of the precorneal tear film, and to investigate the relationship between lipid layer thickness and tear film evaporation. However, the relationship between lipid layer thickness and the rate of evaporation is far from consistent. One possible reason is the inherent limit of contemporary interferometric systems, which employ objectives with relatively long depth of focus (DOF) (>15 μm or more), which tend to collect excessive extra-planar noise. This limitation may negatively affect the accuracy of the characterization and thickness measurement of the lipid layer. The current system incorporated an objective with limited DOF (~1.5 μm) into a custom-built optical microscope to image the tear film lipid layer in humans. An algorithm was also developed to process these images. One major outcome of this system is that thick lipid layers exhibit higher variation in thickness values than thin or normal-thickness lipid layers. The variations may reflect the structural differences of the lipid layer, which may offer a novel dimension to explain the missing correlation between lipid layer thickness and evaporation. In summary, the development of the high resolution microscopy system and associated data processing algorithm may provide new insights into the lipid layer structure, topography and their relation to the tear film evaporation rate.
关键词： tear film,dry eye,interferometry,lipid layer thickness
更新于2025-09-04 15:30:14
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In-line Metrology for Characterization and Control of Extreme Wafer Thinning of Bonded Wafers
摘要： The pace of innovation in device packaging techniques has never been faster and more interesting. Previously, data were sent through wires, whereas in recent packages, components are connected directly using different 3D interconnect technologies. As the 3D interconnect density is increasing exponentially, pitches need to reduce. Current interconnect technologies available in 3D-Stacked IC devices do not offer such high densities. Parallel front-end of line wafer processing in combination with wafer-to-wafer bonding and extreme wafer thinning steps in the 3D System on Chip integration technology schemes enable the increase of 3D interconnect density. During the extreme wafer thinning process pathfinding and development, different thinning techniques were evaluated to target a final Si thickness specification. In this paper, metrology use cases that were applied in this pathfinding and development phase are demonstrated. Metrology data enabled us to determine where the extreme wafer thinning process could be improved. The same techniques were used to validate the improvements and to monitor process stability.
关键词： Extreme wafer thinning,Wafer-to-wafer bonding,Wafer edge defectivity,Final Si thickness control
更新于2025-09-04 15:30:14
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Influence of uveitis on Bruch’s membrane opening minimum rim width and retinal nerve fibre layer thickness measurements
摘要： background/aims To assess the impact of papillary leakage and active inflammation on optical coherence tomography (OCT)-based retinal nerve fibre layer thickness (RNFLT) and Bruch’s membrane opening minimum rim width (BMO-MRW) measurements in uveitic eyes with and without secondary glaucoma. Methods Prospective, single-centre analysis of patients with uveitis. All patients included received a fluorescein angiography examination and an OCT scan measuring the BMO-MRW and the RNFLT in three concentric peripapillary ring scans. results Overall, 95 eyes of 56 patients were enrolled. Papillary leakage and active inflammation were present in 39 (41%) and 57 (60%) eyes, respectively. Twenty-one eyes were classified as glaucomatous; 10 of those glaucomatous eyes showed papillary leakage. Both BMO-MRW and RNFLT measurements were significantly increased in eyes with papillary leakage (BMO-MRW: p=0.0001; RNFL: first to third ring (p<0.0001)). Active inflammation led to a significantly thickened RNFLT (first ring: p=0.0026; second ring: p=0.0009; third ring: p=0.0002) while only a trend towards increased values could be observed in the BMO-MRW measurements (p=0.3063). Glaucomatous eyes with papillary leakage demonstrated significantly higher values on both BMO-MRW and RNFLT measurements than glaucomatous eyes without leakage (BMO-MRW: p=0.0159; RNFL: first ring: p=0.0062; second ring: p=0.0037; third ring: p=0.0197). No significant difference could be observed between glaucomatous eyes with leakage and non-glaucomatous eyes without leakage (BMO-MRW: p=0.4132; RNFL: first ring: p=0.5412; second ring: p=0.3208; third ring: p=0.1164). Conclusions The OCT scanning parameters BMO-MRW and RNFLT were significantly influenced by papillary leakage in uveitic eyes with and without glaucoma. RNFLT values were also significantly increased while active inflammation was present. In patients with uveitis, these OCT-based imaging tools should be interpreted with caution, especially in those with papillary leakage or active inflammation.
关键词： uveitis,optical coherence tomography,retinal nerve fibre layer thickness,Bruch’s membrane opening minimum rim width,glaucoma
更新于2025-09-04 15:30:14
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Elevated Choroidal Thickness and Central Serous Chorioretinopathy in the Fellow Eyes of Patients with Circumscribed Choroidal Hemangioma
摘要： Objective: To determine whether increased choroidal thickness (CT) is associated with circumscribed choroidal hemangioma (CCH) and whether patients with CCH are predisposed to central serous chorioretinopathy (CSCR). Methods: We performed a retrospective consecutive observational study of 15 fellow eyes of 15 patients who had CCH. A- and B-scan ultrasonography, fluorescein angiography (FA), and optical coherence tomography (OCT) findings were reviewed to confirm the diagnosis of CCH. Fellow eye CT was measured using enhanced depth imaging OCT. FA, indocyanine green angiography, and OCT images of fellow eyes were reviewed for signs of CSCR. Results: Mean subfoveal CT was significantly greater in the fellow eyes of patients with CCH than in age-matched normal eyes (p = 0.004). Three of 15 (20.0%) fellow eyes of CCH patients had retinal pigment epithelium disruptions and/or pigment epithelial detachments indicative of previous asymptomatic CSCR. Conclusion: In this pilot study, elevated CT was associated with a risk of developing CCH as well as CSCR in patients of varying ages. Patients diagnosed with CCH should be screened for CSCR in the fellow eye. Further exploration of this association may reveal useful clues about the biology of abnormally elevated choroidal hyperpermeability and its various clinical manifestations.
关键词： Serous chorioretinopathy,Choroidal hemangioma,Choroidal thickness,Contralateral eye
更新于2025-09-04 15:30:14
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Choroidal structural analysis in eyes with diabetic retinopathy and diabetic macular edema—A novel OCT based imaging biomarker
摘要： To evaluate structural changes in the choroid among patients with diabetic macular edema (DME), with varying grades of diabetic retinopathy (DR), using enhance depth imaging spectral domain optical coherence tomography (EDI SD-OCT) scans. A cross-sectional study was conducted on 82 eyes with DR and DME and 86 healthy control eyes. Eyes with DME were classified according to the severity of DR as per the international DR severity scale. Sub foveal choroidal thickness (SFCT)was obtained using EDI SD-OCT scans. These scans were binarized into luminal and stromal areas, to derive the choroidal vascularity index (CVI). CVI and SFCT were analyzed between the study and control group using paired-T test. Tukey’s test was used to correlate the differences in CVI and SFCT between different grades of DR. Further analysis was done to look for the effect of DR severity and type of DME on CVI as well as SFCT using correlation coefficient and linear regression analysis. SFCT was significantly increased in eyes with DME as compared to the controls (334.47 ±51.81μm vs 284.53±56.45μm, p<0.001), and showed an ascending trend with worsening of DR, though this difference was not statistically significant [mild non-proliferative diabetic retinopathy (NPDR) = 304.33±40.39μm, moderate NPDR = 327.81±47.39μm, severe NPDR = 357.72±62.65μm, proliferative DR (PDR) = 334.59±47.4μm, p-0.09]. CVI was significantly decreased in DME with DR eyes as compared to controls (63.89±1.89 vs 67.51 ±2.86, p<0.001). CVI was also significantly decreased with worsening DR (mild NPDR = 66.38±0.3, moderate NPDR = 65.28±0.37, severe NPDR = 63.50±0.47, PDR = 61.27±0.9, p<0.001). SFCT and CVI are dynamic parameters that are affected by DME. Unlike CVI, SFCT is also affected by ocular and systemic factors like edema and hypertension. CVI may be a more accurate surrogate marker for DME and DR and can potentially be used to monitor the progression of DR.
关键词： choroidal vascularity index,diabetic macular edema,subfoveal choroidal thickness,optical coherence tomography,diabetic retinopathy
更新于2025-09-04 15:30:14
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Evaluation of systemic risk factors in different optical coherence tomographic patterns of diabetic macular edema
摘要： ● AIM: To elucidate the relationship between systemic risk factors and different patterns of diabetic macular edema (DME) determined with optical coherence tomography (OCT). ● METHODS: In this cross-sectional study, DME was classified by OCT as diffuse retinal thickness (DRT), cystoid macular edema (CME) and serous retinal detachment (SRD) and the relationship between the systemic risk factors and DME patterns was evaluated. ● RESULTS: Of the 57 patients with DME, 21 (36.8%) had DRT, 24 (42.1%) had CME and 12 (21.0%) had SRD. Micro- or macro-albuminuria was significantly higher in the DRT pattern (61.9%) compared with the SRD (50.0%) and CME patterns (25.0%; P=0.040). Hemoglobin A1c (HbA1c) level was significantly higher and patients were younger in the DRT pattern group (P=0.034, P=0.032). Best corrected visual acuity was the worst and central macular thickness was the thickest in the CME pattern group. ● CONCLUSION: Micro- or macro-albuminuria may be more frequent and HbA1c level may be higher in patients with DRT. These patients are also seen to be younger than patients with non-DRT.
关键词： diabetic macular edema,optical coherence tomography,serous retinal detachment,diffuse retinal thickness,cystoid macular edema
更新于2025-09-04 15:30:14
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Choroidal atrophy in a patient with paraneoplastic retinopathy and anti-TRPM1 antibody
摘要： The purpose of this paper is to report choroidal atrophy in a patient with cancer-associated retinopathy who had autoantibodies against the transient receptor potential cation channel, subfamily M, member 1 (TRPM1). A 69-year-old man visited our clinic in July 2010 with complaints of blurred vision and night blindness in both eyes. The full-field electroretinograms were negative type, indicating ON bipolar cell dysfunction. General physical examination revealed small cell carcinoma of the lung, and Western blot of the patient’s serum showed autoantibodies against TRPM1. We diagnosed this patient with cancer-associated retinopathy and retinal ON bipolar dysfunction due to anti-TRPM1 autoantibody. We followed him for more than 2 years from the initial visit and his symptoms have not changed. However, consistent with the choroidal hypopigmentation of the fundus, spectral domain optical coherence tomography showed a decrease in choroidal thickness of about one third over a 2-year follow-up period. We suggest that this case of gradually progressive choroidal atrophy was caused by the autoantibody against TRPM1 directly, because TRPM1 is expressed not only on ON bipolar cells but also on melanocytes. These findings indicate that we should be aware of choroidal thickness in patients with paraneoplastic retinopathy who have retinal ON bipolar dysfunction with the anti-TRPM1 antibody.
关键词： cancer-associated retinopathy,choroidal thickness,TRPM1,paraneoplastic retinopathy,melanocyte
更新于2025-09-04 15:30:14