扫描信号强度对OCTA测量正常人黄斑浅层血流的影响

目的：:研究扫描信号强度（SS）对光学相干断层扫描血管成像（OCTA）测量正常人黄斑浅层血流密度的影响。方法：:系列病例研究。对2020年9—12月在北京同仁医院进行健康体检的某事业单位在职职工进行系统眼科检查,应用光学相干断层扫描（OCT）和OCTA测量平均黄斑节细胞内丛状层（mGCIPL）厚度和黄斑6 mm×6 m...     

Gel Point Determination in Resin Transfer Molding Process with Fiber Bragg Grating Inscribed in Side-Hole Elliptical Core Optical Fiber

Material as well as process variations in the composites industry are reasons to develop methods for in-line monitoring, which would increase reproducibility of the manufacturing process and the final composite products. Fiber Bragg Gratings (FBGs) have shown to be useful for monitoring liquid-composite molding processes, e.g., in terms of online gel point detection. Existing works however, focus on in-plane strain measurements while out-of-plane residual strain prevails. In order to measure out-of-plane strain, FBG inscribed in highly birefringent fiber (HB FBG) can be used. The purpose of this research is the cure stage detection with (a) FBG inscribed in single mode and (b) FBG inscribed in highly-birefringent side-hole fiber in comparison to the reference gel point detected with an in-mold DC sensor. Results reveal that the curing process is better traceable with HB FBG than with regular FBG. Thus, the use of HB FBG can be a good method for the gel point estimation in the RTM process.     

Europium(III)-Doped Gadolinium(III) Complex for High-Sensitivity Temperature Sensing in the Physiological Range

A new Eu³⁺-doped Gd³⁺ complex of formula [Eu_0.0135Gd_0.9865(pta)₃me-phen] was synthesized and structurally characterized (Hpta = benzoyltrifluoroacetone, me-phen = 5-methyl-1,10-phenanthroline). The photoluminescence study revealed that when the compound was excited at RT, under a 457 nm continuous laser, the material exhibited high luminescence due to the antenna effect of the ligands, as well as a good balance between the phosphorescence from the spin-forbidden triplet (from the organic ligands), and the characteristic lanthanide f-f transitions. The ratio between the previous emissions drastically changed when the sample was heated up to 62 °C inside a tubular furnace. This ratio was investigated using the luminescence intensity ratio method, to analyze the capabilities of the sample as a temperature sensor. The relative sensitivity reached a maximum of 11.4 °C⁻¹ %, maintaining a detection limit below 0.15 °C for the whole temperature range.     

A Gaussian to Vector Vortex Beam Generator with a Programmable State of Polarization

We study an optical device designed for converting the polarized Gaussian beam into an optical vortex of tunable polarization. The proposed device comprised a set of three specially prepared nematic liquid crystal cells and a nano-spherical phase plate fabricated from two types of glass nanotubes. This device generates a high-quality optical vortex possessing one of the multiple polarization states from the uniformly polarized input Gaussian beam. Its small size, simplicity of operation, and electrical steering can be easily integrated into the laboratory and industrial systems, making it a promising alternative to passive vortex retarders and spatial light modulators.     

Dynamic Ranges of Retinal Nerve Fiber and Optic Nerve Head Parameters Measured Using Optical Coherence Tomography in Glaucoma: A Longitudinal Study

PurposeTo evaluate the dynamic range of retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters measured using optical coherence tomography (OCT) in conditions ranging from nonglaucomatous status to advanced glaucoma by longitudinal observation.MethodsA total of 15 eyes from 12 participants with glaucoma progression from a nonglaucomatous status to advanced glaucoma were included. The RNFL and ONH parameters were compared between the nonglaucomatous and advanced stages within the same eye. The absolute and relative changes in OCT parameters were analyzed.ResultsThe median highest intraocular pressure was 42.5 mmHg (interquartile range, 37.5 to 54.5 mmHg), and the final mean deviation of the visual field test was −24.68 dB (interquartile range, −23.93 to −31.13 dB). The median relative changes in RNFL thickness were −40.6% in the overall area, and −51.9%, −21.4%, −51.1%, and −41.8% in the superior, nasal, inferior, and temporal quadrants, respectively (all p < 0.05). Relative changes in the rim area, disc area, average cup to disc ratio, vertical cup to disc ratio, and cup volume were −56.64%, 0.59%, 62.10%, 66.0%, and 337.90%, respectively (all p < 0.05, except for disc area with a p-value of 0.753).ConclusionsThe dynamic range of the RNFL thickness ranged from 40.6% to 51.9%, and the dynamic range of the ONH parameters ranged from 56.64% to 337.90%. During the course of glaucoma progression, the cup volume showed the widest dynamic range. However, the disc area did not show significant changes.     

原发性开角型青光眼黄斑区视网膜厚度与多焦视网膜电图变化的关系

目的 探讨原发性开角型青光眼（POAG）患者黄斑区视网膜厚度与相对应的视网膜功能改变的关系。方法 对24例（43只眼）POAG患者的早期、进展期和晚期患眼进行光学相干断层扫描（OCT）及多焦视网膜电图（ERG）的检查。所得数据应用SPSS统计分析软件进行处理,并做线性相关分析。结果早期的开角型青光眼患者中OCT所测黄斑区视网膜厚度与mERG1环L波潜伏期有显著性负相关（γ=-0．72,P〈0．05,t=2．936）;晚期POAG患者中OCT所测黄斑区视网膜厚度与mERG2,3环b波潜伏期有显著性负相关（γ=-0．666,γ=-0．702,t=2．676,t=2．956,P〈0．05）;对早期,进展期和晚期的开角型青光眼患者OCT所测黄斑区厚度进行比较,显示早期OCT黄斑厚度与晚期相比有极显著性差异,P〈0．01;进展期与晚期相比有显著性差异,P〈0．05,F=5．018。结论POAG患者黄斑区神经上皮厚度的改变影响了黄斑区局部视网膜的功能状态,主要表现为与mERG的b波潜伏期有一定相关性;早期POAG患者眼底视网膜组织形态学上无明显改变时,视网膜功能已经有了改变,OCT与mERG检查对于POAG临床的早期诊断与治疗具有指导性的意义。     

高度近视眼黄斑区神经上皮层厚度的OCT检测研究

目的探讨高度近视眼黄斑区视网膜神经上皮层厚度的变化。方法选取200／年5月至2007年12月在我院就诊并行光学相干断层扫描（OCT）检查的高度近视眼患者64例（64只眼）和正常对照者铝例（48只眼）,分为高度近视组和正常对照组,测量其黄斑中心凹、中心凹上下方及颞侧、鼻侧各750μm处的视网膜神经上皮层厚度,比较两组有无显著性差异。结果高度近视组的黄斑区视网膜神经上皮层厚度均低于正常对照组,二者差异有显著意义（P〈0．01）。结论高度近视眼黄斑区视网膜神经上皮层厚度明显低于正常眼,OCT能够精确量化测定该厚度变化。