Ocular Development in Infancy/Early Childhood

描述(申请人？S摘要)产后眼球运动最快的阶段 生长发生在生命的头几年。这一时期的特点是 正规化，平均数量和变异性都在减少 屈光不正。绝大多数婴儿达到正视屈光 到三岁时状态，没有明显的屈光不正。尽管 眼睛在三岁后持续生长，正视维持在 大多数儿童到九岁左右才会出生。当时流行的是 近视开始增加，即使眼睛平均生长较慢 与三岁相比。目前尚不清楚正视是如何在 儿童早期发育较快，但未能在整个儿童时期持续 在学年中增长较慢的时期。 伯克利婴儿生物测量学研究(BIBS)的初始阶段为五年 3岁婴幼儿眼部成分的纵向研究 几个月到三年。它调查了眼睛里发生的变化 婴儿和蹒跚学步的儿童在眼睛发育的正规期。 该项目在未来三年内继续实施的目标是 确定三岁后正视是如何维持的。我们会 评估正视由视觉反馈维持的相互矛盾的假说 从散焦或调节滞后，而不是由被动保持 通过透镜倍数的变化来平衡固有轴向生长的过程 等效折射率降低。这一目标将通过以下方式实现 屈光不正、调节反应、角膜的纵向测量 曲率、前房深度、晶状体厚度和表面 原始胸围的曲率、玻璃体腔深度和轴向长度 参与者年龄在3至6岁之间。除了建立 所有眼球的标准生长曲线？S光学元件前六名 寿命，这些数据将允许评估预测因素 基于这些参数的较早值的成熟屈光误差。 从婴儿期到儿童期的纵向屈光和生物测量数据 将使研究眼睛对离焦的反应成为可能， 哪些组成部分负责维持正视， 眼生长中的调节，以及眼球的成分和屈光发育 生命的头几年与儿童后期的这些参数有关。

DESCRIPTION (Applicant?s Abstract) The most rapid phase of post-natal ocular growth occurs during the first years of life. This period is characterized by emmetropization, a reduction in both the average amount and the variability in refractive error. The vast majority of infants reach an emmetropic refractive state by three years of age and have no significant refractive error. Despite continued growth of the eye after the age of three, emmetropia is maintained in most children until the age of about nine years. At that time the prevalence of myopia begins to increase even though ocular growth is slower on average compared to age three. It is not understood how emmetropia is maintained during more rapid growth in early childhood, yet fails to be sustained throughout the period of slower growth in the school years. The initial phase of the Berkeley Infant Biometry Study (BIBS) was a five-year longitudinal study of the ocular components in infants and toddlers aged three months to three years. It investigated the changes occurring in the eyes of infants and toddlers during the ernmetropizing period of ocular development. The goal of the continuation of this project over the next three years is to determine how emmetropia is maintained after three years of age. We will evaluate competing hypotheses that emmetropia is maintained by visual feedback from defocus or accommodative lag as opposed to being maintained by passive processes where innate axial growth is balanced by lens power changes due to decreases in equivalent refractive index. This goal will be accomplished by longitudinal measurement of refractive error, accommodative response, corneal curvature, anterior chamber depth, crystalline lens thickness and surface curvatures, vitreous chamber depth, and axial length in the original BIBS participants when they are between 3 and 6 years of age. Besides establishing normative growth curves for all the eye?s optical components for the first six years of life, these data will allow for evaluation of predictive factors for mature refractive error based on the earlier values for these parameters. Longitudinal refractive and biometric data from infancy through early childhood will make it possible to investigate the responsiveness of the eye to defocus, what components are responsible for maintaining emmetropia, the role of accommodation in ocular growth, and how component and refractive development in the first years of life are related to those parameters in later childhood.