水凝胶角膜接触镜材料研究进展

以角膜接触镜材料的基本要求为出发点,在相关文献和专利的基础上综述了目前软性亲水的水凝胶角膜接触镜材料的研究进展及发展趋势.特别针对传统型水凝胶角膜接触镜的透氧和均一成分构建的局限,分别重点介绍了高透氧角膜接触镜材料及互穿网络角膜接触镜材料.前者通过引入硅氧烷成分使角膜接触镜的延长配戴成为可能,后者则通过交联互锁的结构实现了材料的均一性和稳定性,从而为角膜接触镜材料在药物释放和治疗用途上的更广泛应用创造了条件.     

基于角膜接触镜的眼药缓释水凝胶材料研究进展

常用的眼用药物制剂为滴眼剂或者眼膏剂,具有使用不方便、药物利用效率低、易引起副作用、需频繁施用、影响视力等缺点.采用角膜接触镜缓释的眼用药物制剂可克服这些缺点,因而受到研究人员的重视.综述了基于角膜接触镜、适于缓释眼用药物的poly-HEMA(聚甲基丙烯酸羟乙酯)水凝胶、硅氧烷水凝胶、分子印迹聚合物水凝胶以及含离子配体水凝胶的研究进展,并展望了适于角膜接触镜缓释的眼用制剂的水凝胶材料的发展前景.     

莫尔条纹法(溶液中)测量角膜接触镜后顶焦度的原理分析

本文详述了莫尔条纹法测量角膜接触镜后顶焦度的基本原理以及相应的理论计算,对目前测量角膜接触镜后顶焦度的两种方法即空气中(传统的焦度计法)和溶液中(莫尔条纹法)作了比较,并提出了对角膜接触镜后顶焦度量值进行统一的展望.     

生物医用眼科材料的研究

主要综述了用于眼科的生物医用材料的种类、结构特点及其在眼科中应用的性能,重点介绍了用于人工角膜的光学镜柱材料和支架材料、人工晶状体材料、人工玻璃体材料、人工眼球义眼台和义眼材料、人工泪道和泪液材料、角膜接触镜材料及眼科药物载体材料,展望了生物医用眼科材料的发展方向.     

NVP-HEMA角膜接触镜材料的透氧性能

以过氧化二苯甲酰(BPO)为引发剂，N-乙烯基吡咯烷酮(NVP)和甲基丙烯酸β-羟乙酯(HEMA)在一定温度下共聚得水凝胶，可作为软性角膜接触镜材料．实验发现，随NVP含量的增大，水凝胶的含水量越大，透氧性增大，水凝胶材料的透氧率(Dk／L)的倒数与其厚度成正比．并自行设计了一套角膜接触镜材料透氧性能的测试装置、     

角膜接触镜专用顶焦度标准器的研制

论述了建立角膜接触镜专用顶焦度标准器的必要性和研制方案所用的原理,并给出接触镜专用项焦度标准器的测试结果和误差分析,最后讨论了对检测角膜接触镜的焦度计如何校准的问题。     

莫尔条纹法（溶液中）测量角膜接触镜后顶焦度的原理分析

本文详述了莫尔条纹法测量角膜接触镜后顶焦度的基本原理以及相应的理论计算,对目前测量角膜接触镜后顶焦度的两种方法即空气中（传统的焦度计法）和溶液中（莫尔条纹法）作了比较,并提出了对角膜接触镜后顶焦度量值进行统一的展望。     

丙烯酸酯树脂的医疗用途

本文介绍了丙烯酸酯树脂的优异性能和医疗用途。由于这种高分子材料具有组织相容性好 ,机械强度高 ,无毒和室温固化等性能 ,可在医疗方面广泛应用 ,如用作骨水泥、齿科充填材料、角膜接触镜、组织粘合剂、烧伤敷料和介入栓塞剂等。     

共聚物水凝胶的合成及其溶胀性能研究

以过氧化二苯甲酰(BPO)为引发剂，合成了N-乙烯基吡咯烷酮(NVP)-甲基丙烯酸肛羟乙酯(HEMA)-甲基丙烯酸丁酯(BMA)共聚物水凝胶，可作为软性角膜接触镜材料。探讨了不同比例的NVP、HEMA、BMA对材料溶胀性能的影响。     

复合水凝胶角膜接触镜材料的设计与合成

通过高聚物分子设计的方法,以吸水倍率低的HEMA水凝胶为基体材料,以吸水倍率高的PVPP(交联NVP)颗粒为分散相,制备出了具有明显相界面层的复合水凝胶角膜接触镜材料.通过大量实验表明其制备工艺为:PVPP颗粒与单体HEMA的质量比为10:90,致孔剂PEG400为35%(wt,相对于总反应物),BPO为0.4%(wt,相对于反应单体),反应混合物混合均匀后立即压片、放入温度为75℃的水浴中,反应12h.为下一步研究具有药物缓释功能的、可重复利用的角膜接触镜奠定了基础.     

角膜接触透镜材料的研究进展

综述了接触透镜材料的研究进展,接触透镜从材料方面主要分为硬镜和软镜;介绍了各种透镜材料的成分、性能,并对其优缺点进行评定.聚甲基丙烯酸甲酯(PMMA)是最初的接触透镜材料,随后研制出透气性硬镜材料(RGP)以保持佩戴角膜健康.为改善佩戴舒适性,广泛研究水凝胶类软接触透镜材料,主要有聚甲基丙烯酸β-羟乙酯(HEMA)、聚乙烯吡咯烷酮(PVP)和聚乙烯醇(PVA)等材料;为提高软镜的透氧性等性能,目前研究的热点是高透氧性软接触透镜材料,主要以有机硅、有机氟等大分子单体合成水凝胶材料,以及生物改性的软镜材料.     

Investigation of the polarization optics of the living human cornea and lens with purkinje images

We present what to our knowledge is a new method for assessing the polarization optics of the cornea and lens, by examining the state of polarization of the first, second, and fourth Purkinje images. When linearly polarized light is incident on the cornea at 70 degrees to the line of gaze along the horizontal meridian, and then traverses the cornea, or the cornea and the lens, the emergent light is elliptically polarized. The degree of ellipticity varies widely between subjects. The results indicate that both the cornea and the lens may be optically active and to our knowledge are the first to suggest that the cornea may exhibit circular birefringence.     

Non-rotational aspherical models of the human optical system

The aim of this work was to define three-dimensional (3D) non-rotational aspherical parametric models for the human cornea and lens using computational geometry and CAD representations. The hyperbolic cosine based function is used for the cornea and a parametric model is used for lens modeling. Data analysis and visualization of 3D non-rotational models were made using the Rhinoceros CAD software and MATLAB software was used for numeric computation. We combined, implemented, and evaluated these models with a 3D ray-tracing in order to fully analyze the human eye model. It was found that 3D non-rotational aspherical models for the human eye could be more accurately modeled and rendered for analysis with finite element method. The objective of this study is to present and analyze mathematical models of the cornea and lens and to highlight the potential of optical applications of the eye models containing astigmatic surfaces, which are more close to the real eye than spherosymmetric eye models.     

Property-based design: optimization and characterization of polyvinyl alcohol (PVA) hydrogel and PVA-matrix composite for artificial cornea

Each approach for artificial cornea design is toward the same goal: to develop a material that best mimics the important properties of natural cornea. Accordingly, the selection and optimization of corneal substitute should be based on their physicochemical properties. In this study, three types of polyvinyl alcohol (PVA) hydrogels with different polymerization degree (PVA1799, PVA2499 and PVA2699) were prepared by freeze-thawing techniques. After characterization in terms of transparency, water content, water contact angle, mechanical property, root-mean-square roughness and protein adsorption behavior, the optimized PVA2499 hydrogel with similar properties of natural cornea was selected as a matrix material for artificial cornea. Based on this, a biomimetic artificial cornea was fabricated with core-and-skirt structure: a transparent PVA hydrogel core, surrounding by a ringed PVA-matrix composite skirt that composed of graphite, Fe-doped nano hydroxyapatite (n-Fe-HA) and PVA hydrogel. Different ratio of graphite/n-Fe-HA can tune the skirt color from dark brown to light brown, which well simulates the iris color of Oriental eyes. Moreover, morphologic and mechanical examination showed that an integrated core-and-skirt artificial cornea was formed from an interpenetrating polymer network, no phase separation appeared on the interface between the core and the skirt.     

眼球系统中关键屈光元件的光学模型研究

角膜和晶状体是人眼光学系统中两个关键的屈光元件,为了理解眼内各介质和整个眼球的屈光状态以及视网膜上的成像,有利于眼科临床方面的应用,需要分别对二者进行光学特性模型的分析与研究。根据角膜和晶状体的光学特性,应用光学设计软件Zemax和有关的数学工具,从光学成像角度,分别对角膜和晶状体模型进行研究:基于结合人眼光学模型的角膜双二次曲面模型的建立方法,统计分析了我国人眼实测角膜参数的数据;通过对晶状体折射率分布特点的分析,分别在轴向和径向上进行了综合分析。最后给出了符合我国人眼特点的角膜面型的统计数值,完善了我国人眼角膜光学模型的建立;获得了形式简单且能够表示晶状体折射率分布一般特征的梯度渐变模型表达式。基于收集的我国人眼实测数据的角膜面型模型和晶状体梯度渐变形式的折射率模型,为解决人眼光学系统研究中的关键问题提供了新的方案和思路。     

Ophthalmic application of poly(HEMA)s containing nanoparticles and dimethylacrylamide

High functional ophthalmic lens materials, poly(HEMA-co-MMA)s were prepared by the copolymerization of HEMA, MMA, MA, EDGMA, and N,N-dimethylacrylamide in the presence of platinum nanoparticles with antimicrobial properties. The hydrophilic monomer N,N-dimethylacrylamide has excellent biocompatibility and oxygen transmissibility. The combination where platinum nanoparticles were added produced a colorless transparent lens. The water contents were in the range of 36.68-44.08% and the refractive index was measured to be in the range of 1.424-1.436. Meanwhile, the oxygen transmissibility ranged from 11.13 x 10(-11) to 17.63 x 10(-11) (cm2/sec) (mlO2/ml x mm Hg) increased with increasing the addition ratio of N,N-dimethylacrylamide. The physical properties measurements of the produced polymers showed that the nanoparticles did not show significant effect on the water content and refractive index of the hydrogel contact lens, but the materials effected to reduce oxygen permeability to a certain extent. The copolymers have excellent oxygen permeability, indicating that the material can be used to fabricate hydrogel contact lenses with high oxygen transmissibility.