ADVANCED ELECTRON MICROSCOPIC STUDIES OF CRYSTALLINE LEN

我们研究计划的长期目标一直是，并将继续 可以说，对正常人类晶状体形态的阐明与 晶状体功能，以及年龄相关和/或病理变化在 镜片表现为镜片光学性能受损，最终导致 特殊的白内障。 后囊下型白内障的初步研究 视网膜色素变性(RP)的实验动物模型 羟甲基戊二酰辅酶A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 后缝解剖中的渐进性妥协而不是 向后极迁移的发育不良的“韦氏”细胞的增殖。 在我们之前的研究中，我们已经开发并成功地应用了 相关技术，允许准确量化 晶状体缝合解剖的进行性、负性变化 导致浑浊。因此，在五年中提出的研究 这笔赠款的目的是实现以下具体目标： 首先，要确定一个可比的、进步的和可量化的、 晶状体结构(尤其是缝线)之间存在负相关 解剖学)和功能(球差，即焦距 可变性)作为以下结果的PSC形成之前、期间和之后 不同的病因包括：1)长期治疗 HMG-CoA还原酶抑制剂；2)RP；3)治疗 类固醇；4)糖尿病；5)艾滋病。第二，进一步阐明 灵长类晶状体细胞的超微结构(中央，萌发前， 生殖区和过渡区上皮细胞，以及 拉长、成熟和老化的纤维)作为发育、生长、 年龄和病理学。关于第一套具体目标：光学目标 质量(焦距可变性；即球差) 实验动物晶状体将通过低倍数的分析进行评估 我们自己设计的氦-霓激光扫描装置，特别参考 到晶状体缝线。然后，激光扫描的透镜将精确地 通过我们开发的一种方法进行解剖，允许检索 完整的从前向下的完整缝合模式 和用于扫描电子结构分析的后极 显微镜(扫描电子显微镜)。以这种方式，晶状体缝合解剖作为 可以准确地预测发育、生长、年龄和白内障的发生 特色化的。所有晶状体解剖的原位三维缝线解剖 然后通过3D-CAD重建分析来确定 确定结构相关性是否会对透镜产生不利影响 功能由激光扫描分析，对应于PSC的不混浊。 可比较的实验动物晶状体组也将接受 生物显微镜裂隙灯分析以确定晶状体生长是否受到影响 表现为异常缝合，与区域的产生相关 不连续通常不是这些非 灵长类晶状体。这些结果将与模拟裂隙灯进行比较 从激光扫描的晶状体的3D-CAD重建和 通过以上结果拍摄的人类PSCs的裂隙灯图像 描述了病因。 对透镜之间的相互关系有了更好的理解 由我们开发的技术提供的结构/功能 在我们的实验室中应用，那么在 这一建议可能会导致更早的发现和改善临床 不同病因引起的人类PSCs的处理。

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.