A HUMAN ACCOMMODATION MODEL

人眼发生调节的机制是 目前是一个有争议的问题，归因于不同的 睫状肌通过睫状带装置的活动， 玻璃体对TBA前段的液压作用 两者的结合。解决这一争议是一个问题 重要的是，因为调节幅度的年龄相关性丧失 -老花眼-只能被理解，甚至可能被逮捕， 通过对舒适剂老化的理解 机制。因此，这项研究的长期目标是 描述人类调节过程的老化 眼睛。这项赠款提案特别涉及 恒河猴眼的调节与老花眼的发展。 成年恒河猴的住宿和住宿损失将被建模 分析表明，作用于晶状体所需的力已确定 从描述在小范围的调节过程中的透镜变形； 力量的大小和/或模式随年龄的变化将 帮助确定哪些因素会导致衰老 适应性损失。第二种建模方法--有限元 元素分析-也将被用来扩大 学习不需要开发更复杂的 分析公式。基于计算机的光线跟踪研究将 被用来描述成人眼睛的图像形成，并将 被比作人类。复弹性的表征 用动态形状模拟方法研究恒河猴晶状体的特性 它在谐振子中的行为的模型也将是 执行，不仅提供了所需的弹性常数 住宿模型，但也直接检验假设 老花眼是由于晶状体顺应性降低所致。结果是 这些研究的结果将被定量地与 一项关于人类调节和老花眼的等效研究， 目前正在私家侦探的实验室进行。人类和恒河猴 猴子在系统发育上紧密相连，它们的视觉 这两个系统在质量上有很强的相似性 调节机制与前视的发展 在许多方面数量上不同的。拟议的研究将 允许对共同的因素进行表征 这两个物种，并提供了对特定角色的洞察 非共享属性(例如， 不连续)在成像和聚焦过程中。

The mechanism by which accommodation occurs in the human eye is currently a matter of controversy, attributed variously to the action of the ciliary muscle through the zonular apparatus, the hydraulic action of the vitreous on tba anterior segment, or some combination thereof. Resolving this controversy is a matter of importance, since the age-dependent loss of accommodative amplitude - presbyopia - can only be understood, and perhaps arrested, through an understanding of the aging of the accommodative mechanism. The long-term goal of this research, then, is to characterize the aging of the acccmmodative process in the human eye. This grant proposal is specifically concerned with accommodation and the development of presbyopia in the rhesus eye. Adult rhesus accommodation and accomodative loss will be modelled analytically, with the forces needed to act on the lens determined from a description of lens deformation during a small accomodation; changes in the magnitude and/or pattern of forces with age will help to define those factors whose aging contributes to accommodative loss. A second type of modelling approach - finite element analysis - will also be employed to expand the scope of the study without the necessity of developing an even more complex analytical formulation. Computer-based ray-tracing studies will be used to characterize image formation in the adult eye, and will be compared to humans. Characterization of the complex elastic properties of the rhesus monkey lens using dynamic shape analogy modelling of its behavior in a harmonic oscillator will also be performed, providing not only the necessary elastic constants for the accommodation models, but also testing directly the hypothesis that presbyopia is due to decreased lens compliance. The results of these studies will be quantitatively compared to the results of an equivalent study on human accommodation and presbyopia, currently underway in the PI's laboratory. The human and rhesus monkey are closely linked phylogenetically, and their visual systems exhibit strong qualitative similarities in both accommodative mechanism and the development of prestyopia, while differing quantitatively in many respects. The proposed study will allow the characterization of factors shared in common between these two species, and provide an insight into the specific role of non-shared qualities (e.g. the number of the zones of discontinuity) in image formation and the focussing process.