Ocular Development in Infancy/Early Childhood

描述（申请人？摘要）出生后眼部发育最快的阶段 生长发生在生命的最初几年。这个时期的特点是 正视化，平均量和变异性的减少， 屈光不正绝大多数婴儿达到正视眼屈光 三岁时，没有明显的屈光不正。尽管 眼睛在三岁以后继续生长，正视保持在 大多数孩子直到九岁左右。当时流行的 近视开始增加，即使眼睛平均生长较慢 与三岁相比。目前尚不清楚在治疗期间， 更快的增长在幼儿期，但未能持续整个 在学年中增长较慢的时期。 伯克利婴儿生物统计学研究（BIBS）的初始阶段是一个为期五年的研究。 3岁婴幼儿眼成分的纵向研究 几个月到三年它调查了发生在眼睛的变化， 在眼睛发育的正视化时期的婴儿和幼儿。 该项目在今后三年继续实施的目标是， 确定三岁后正视眼是如何保持的。我们将 评价视觉反馈维持正视的相互竞争的假设 从散焦或反射滞后，而不是由被动 先天性轴向生长通过透镜屈光力变化平衡的过程， 等效折射率降低。这一目标将通过 屈光不正、调节反应、角膜的纵向测量 曲率、前房深度、晶体透镜厚度和表面 原始BIBS的曲率、玻璃体腔深度和眼轴长度 参与者年龄在3至6岁之间。除了建立 所有眼睛的正常生长曲线？s光学元件的前六个 年的寿命，这些数据将允许评估的预测因素， 成熟屈光不正的基础上，这些参数的早期值。 从婴儿期到幼儿期的纵向屈光和生物特征数据 将使研究眼睛对散焦的反应成为可能， 什么成分负责维持正视， 调节在眼生长，以及如何组成和屈光发展， 生命的最初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.