AGING EFFECTS ON HUMAN CRYSTALLINE LENS PROPERTIES

调节，眼睛聚焦于附近物体的过程，发生在 通过睫状肌的受控收缩， 具有受控的晶体透镜的弹性松弛。 后者 事件导致透镜形状改变，从而改变其折射率 特性. 然而，这两个过程耦合的手段是 这是一个有争议的问题，目前接受的理论都不能 充分解释了与年龄相关的振幅衰减 （老花眼）。 这一相互竞争的延续建议的目的是 表征人类晶状体透镜特性的变化， 增加透镜老化，包括原位非侵入性技术和体外 使用隔离的死后晶状体，并考虑调节和 在这些研究方面的损失。 对选定的 作为年龄的函数的人类受试者将包括标准的临床 例如角膜厚度测量和角膜曲率测量的技术，以及 Scheimpflug方法收集裂隙灯照片的住宿 每例受试者的透镜，在整个屈光度范围内间隔2个屈光度 范围;分析时，这些照片将提供有关 角膜、前透镜表面和后透镜表面的位置， 以及所有可辨别的曲率的特征， 透镜（例如，相邻不连续区域之间的边界）， 国家的功能。 体外研究将采用 表征透镜弹性、物理 和生物化学性质，以及光学性质的分离死后， 晶状体与年龄和性别的关系 基于计算机的统计软件包 将用于将这些结果与年龄、性别和 （如适用）视敏度，以及修订后的基于计算机的模型， 住宿，其中包括这些数据，并适用于所有 年龄，将制定。 这些研究旨在填补 目前对人类透镜老化过程的理解，并考虑 直接地，可以与人的晶状体中的变化相关联的人的透镜中的变化， 老花眼的发展。 一些可以研究的参数 非侵入性的，以及那些可以被侵入性研究， 与受试者年龄直接相关，因此可以用作“生物标志物”， 衰老的过程

Accommodation, the process by which eyes focus on near objects, occurs in humans through the controlled contraction of the ciliary muscle coupled with controlled elastic relaxation of the crystalline lens. The latter event results in a change in lens shape which alters its refractive properties. The means by which the two processes are coupled, however, is a matter of controversy, and neither of the currently accepted theories can adequately explain the age-related erosion of accommodative amplitude (presbyopia). The purpose of this competing continuation proposal is to characterize changes in human crystalline lens properties as a function of increasing lens age, both in situ with non-invasive techniques and in vitro using isolated post-mortem lenses, and to consider accommodation and accommodative loss in terms of these studies. In vivo studies on selected human subjects as a function of age will include standard clinical techniques such as pachymetry and keratometry, and the use of the Scheimpflug method to collect slit-lamp photographs of the accommodating lens for each subject at 2 diopter intervals over the entire accommodative range; when analyzed, these photos will supply information on relative locations of the cornea, anterior lens surface, and posterior lens surface, as well as characterization of all discernible curvatures associated with the lens (e.g., boundaries between adjacent zones of discontinuity) as functions of accommodative state. In vitro studies will employ both standard and innovative methods to characterize lens elasticity, physical and biodhemical properties, and optical properties of isolated post-mortem lenses as a function of age and sex. Computer-based statistical packages will be used to correlate these results as a function of age, sex, and (where applicable) visual acuity, and a revised computer based model on accommodation, which incorporates these data and which is applicable to all ages, will be formulated. These studies are designed to fill gaps in the current understanding of the human lens aging process, and to consider directly the changes in the human lens which may be associated with the development of presbyopia. Some of the parameters which can be studied non-invasively, as well as those that can be studied invasively, are directly correlated to subject age and can thus be used as "biomarkers" for the aging process.