ADVANCED ELECTRON MICROSCOPIC STUDIES OF CRYSTALLINE LEN

我们的研究计划的长期目标一直是，并将继续下去 也就是说，阐明正常人透镜形态，因为它涉及 透镜功能，以及年龄相关的和/或病理变化如何影响晶状体的功能。 透镜表现为受损的透镜光学器件，最终导致 特殊的白内障 我们的初步研究后囊下白内障（PSC）， 视网膜色素变性（RP）的实验动物模型和 羟甲基戊二酰（HMG）-CoA还原酶抑制剂对PSC的影响 形成，表明这些晶状体的PSC混浊是由于 后缝解剖结构的渐进性损害，而不是来自 增生异常的“Wedl”细胞迁移到后极。 在我们以前的研究中，我们已经开发并成功应用了， 相关技术，允许准确量化 透镜缝合解剖结构的进行性、负性变化， 导致不透明。因此，五年内提出的研究 这笔赠款的目的是实现以下具体目标： 首先，要确定一个可比较的、渐进的、可量化的、 透镜结构（特别是缝合结构）之间存在负相关 解剖学）和功能（球面像差，即焦距 在PSC形成之前、期间和之后， 不同的病因包括：1）长期治疗性治疗， HMG-CoA还原酶抑制剂; 2）RP; 3）用以下药物治疗 类固醇; 4）糖尿病;和5）艾滋病。第二，进一步阐明 灵长类动物透镜细胞的超微结构（中央，萌发前， 萌发和移行区上皮细胞，以及 伸长的、成熟的和老化的纤维）作为发育，生长， 年龄和病理关于第一组具体目标： 质量（焦距可变性;即球面像差） 实验动物晶状体将通过低放大率分析进行评估 我们自行设计氦氖激光扫描装置 到透镜缝合。激光扫描的镜头将被精确地 通过我们开发的方法进行解剖， 完整完整的缝合模式，从前部开始逐渐深入 和后极，用于扫描电子结构分析 显微镜（SEM）。以这种方式，透镜缝合解剖结构作为 发育、生长、年龄和白内障发生可以准确地 表征了解剖的所有晶状体的原位3D缝合解剖结构， 然后通过3D-CAD重建分析确定， 确定是否发现结构相关性对透镜产生不利影响 通过激光扫描分析功能，对应于PSC不透明度。 还将通过以下方法检查可比较的实验动物晶状体组： 生物显微镜裂隙灯分析，以确定透镜生长是否受损 表现为异常缝合，与区域的产生相关 不连续性，通常不是这些非- 灵长类动物的晶状体这些结果将与模拟裂隙灯进行比较 从激光扫描镜头的3D-CAD重建中拍摄的图像， 用裂隙灯拍摄的人类PSC图像， 描述了病因。 随着对透镜之间相互关系的进一步理解， 我们开发的技术所提供的结构/功能， 应用于我们的实验室，那么， 这一建议可以导致早期检测和改善临床 人类PSC的管理作为不同病因的结果。

The long term objective of our research program has been, and continues to be, the elucidation of normal human lens morphology as it relates to lens function, and how age-related and/or pathological changes in the lens are manifested as compromised lens optics leading ultimately to specific cataracts. Our preliminary studies of posterior subcapsular cataracts (PSC) from experimental animal models for Retinitis Pigmentosa (RP) and for the effects of Hydroxymethlyglutaryl (HMG)-CoA reductase inhibitors on PSC formation, suggest that the PSC opacities of these lenses result from a progressive compromise in posterior sutural anatomy rather than from a proliferation of dysplastic "Wedl" cell migrating to the posterior pole. In our previous studies we have developed, and successfully applied, correlative techniques that allow for the accurate quantification of progressive, negative changes in lens sutural anatomy, prior to and resulting in opacification. Thus, the studies proposed in the five years of this grant are designed to accomplish the following specific aims: First, to determine if a comparable, progressive, and quantifiable, negative relationship exists between lens structure (particularly sutural anatomy) and function (spherical aberration, i.e. focal length variability) before, during and after PSC formation, as a consequence of different etiologies including: 1) long term therapeutic treatment with HMG-CoA reductase inhibitors; 2) RP; 3) therapeutic treatment with steroids; 4) diabetes; and 5) AIDS. Second, to further elucidate the ultrastructure of primate lens cells (central, pre-germinative, germinative, and transitional zone epithelial cells, as well as elongating, mature and aged fibers) as a function of development, growth, age and pathology. As regards the first set of specific aims: The optical quality (focal length variability; i.e spherical aberration) of the experimental animal lenses will be assessed by analysis with a low power helium-neon laser scan unit of our own design with particular reference to lens sutures. The laser scanned lenses will then be precisely dissected by a method that we have developed permitting the retrieval of complete intact suture patterns at progressive depths from the anterior and posterior poles for structural analysis by scanning electron microscopy (SEM). In this manner, lens sutural anatomy as a function of development, growth, age and cataractogenesis can be accurately characterized. The in situ 3D sutural anatomy of all lenses dissected as above, will then be ascertained by 3D-CAD reconstructional analysis to determine if structural correlates found to adversely effect lens function by laser scan analysis, correspond to the PSC opacities. Comparable groups of experimental animal lenses will also be examined by biomicroscopic slit-lamp analysis to determine if compromised lens growth manifested as abnormal sutures, correlate with the production of zones of discontinuity that are not normally characteristic of these non- primate lenses. These results will be compared to simulated slit-lamp images taken from the 3D-CAD reconstructions of laser scanned lenses and with slit-lamp images taken of human PSCs resulting from the above described etiologies. With a greater understanding of the inter-relationship between lens structure/function afforded by techniques that we have developed and applied in our laboratories, then the results of studies described in this proposal could lead to the earlier detection and improved clinical management of human PSCs as a consequence of different etiologies.