CILIARY MUSCLE AGING AND PRESBYOPIA

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 目的：通过研究非人灵长类动物的调节和老视的动力学，了解人类老视。 非人类灵长类动物是人类老花眼的首选模型，老花眼是与年龄相关的聚焦能力丧失。焦点取决于透镜改变形状的能力（即透镜增厚和伴随的透镜赤道直径减小）。透镜形状的改变取决于睫状肌的向前和向内运动。以前，我们发现了年龄相关的睫状肌运动的损失，这是更明显的向前，而不是向心矢量。目前的研究结果表明，调节性透镜增厚随年龄的下降比调节性透镜直径的下降更显着。这可能是由于简单的几何/生物物理需要和/或透镜结构固有的老化变化。无论睫状体的收缩状态如何，与年龄相关的晶状体透镜增厚的变化在数量上或机制上可能与晶状体直径的年龄相关变化不同。 睫状肌保持一定向心运动的能力，同时随着年龄的增长经历向前运动的显著损失，也可能对不同的透镜形状变化（即，赤道运动（Equatorial Movements）。无论透镜增厚与透镜赤道运动的年龄相关差异是由于透镜本身还是由于睫状体运动的变化，这些发现都可能为成功的调节性IOL设计提供见解。 在人眼中证实了玻璃体小带的存在。破坏玻璃体悬韧带恢复了老年恒河猴眼的前向肌肉运动。这提出了玻璃体小带可能是生物靶点的可能性，其破坏可用于恢复向前的肌肉运动。此外，玻璃体小带/睫状体平坦部区域的睫状体宽度存在年龄相关性减小，这可能对玻璃体小带张力产生影响，并可能影响透镜形状，从而影响调节。同样，这些发现可能为成功的调节性IOL设计提供一些见解。 这项研究使用WNPRC研究服务。 出版物： Croft MA、McDonald JP、Nadkarni NV、Lin TL、考夫曼PL：猴中睫状体向心运动相对于透镜向心运动的晶状体相关变化。Exp Eye Res 89：824-832，2009年（12月）PMCID 278077 L考夫曼PL，Wasielewski R，Lin TL，Croft MA：人类和猴子眼中玻璃体小带的形态和功能。Invest Ophthalmol维斯科学，印刷前电子版，2009年10月8日。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Objective: To understand human presbyopia by studying the dynamics of accommodation and presbyopia in nonhuman primates. Nonhuman primates are the preferred model for human presbyopia, the age-related loss of the ability to focus. Focus depends on the ability of the lens to change shape (i.e. lens thickening and a concomitant decrease in lens equatorial diameter). Lens shape change depends upon forward and inward movement of the ciliary muscle. Previously, we found an age-related in loss in ciliary muscle movement that was more pronounced in the forward rather than the centripetal vector. Current findings show that accommodative lens thickening declined with age more markedly than accommodative lens diameter. This could be due to simple geometric / biophysical necessity and/or aging changes inherent in lens structure. Age-related changes in accommodative lens thickening may not be the same quantitatively or mechanistically as the age-related changes in accommodative diameter, regardless of the ciliary body state of contraction. The ciliary muscle's ability to maintain some centripetal movement while undergoing a dramatic loss in forward movement with increasing age may also have an impact on differential lens shape changes (i.e., accommodative thickening vs. equatorial movements). Whether the age-related differences in lens thickening vs. lens equator movements are due to the lens itself or to changes in ciliary body movements, these findings may provide insights into successful accommodating IOL design. The presence of the vitreous zonule was confirmed in the human eye. Disruption of the vitreous zonule restored forward muscle movement in the older rhesus monkey eye. This raises the possibility that the vitreous zonule could be a biological target, the disruption of which could be used to restore forward muscle movement. Further, there was an age-related decrease in width of the ciliary body in the vitreous zonule/pars plana region and this may have an effect on the vitreous zonule tension and may affect lens shape and thereby accommodation. Again, these findings may provide some insight into successful accommodating IOL design. This research used WNPRC Research Services. PUBLICATIONS: Croft MA, McDonald JP, Nadkarni NV, Lin TL, Kaufman PL: Age-related changes in centripetal ciliary body movement relative to centripetal lens movement in monkeys. Exp Eye Res 89:824-832, 2009 (Dec) PMCID278077 L¿tjen-Drecoll E, Kaufman PL, Wasielewski R, Lin TL, Croft MA: Morphology and accommodative function of the vitreous zonule in human and monkey eyes. Invest Ophthalmol Vis Sci, Epub ahead of print, Oct 8, 2009.