EFFECTS OF VIEWING DISTANCE ON EYE GROWTH & REFRACTIVE DEVELOPMENT

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来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 中心，但不一定是研究者所在的机构。 近视是一种视觉障碍，影响25%的美国人，每年花费40亿美元。它最近已被美国国立卫生研究院确定为优先解决的健康差距，因为它可以不成比例地影响一些少数群体。虽然其病因仍然未知，但研究表明遗传和环境因素的作用。在儿童中，如果父母双方都是近视眼，而且如果一方阅读超过平均水平，则近视的可能性更高。动物模型试图通过强调视网膜图像的质量，使用形觉剥夺或恒定散焦来识别环境影响的性质。目前SCORE项目的论点是，观看距离也影响眼睛的生长和屈光状态。我们的初步研究支持这一论断，我们接下来提出测试以下假设的几个推论：长时间暴露于视觉刺激在近视距足以诱导过度的眼球伸长和相对近视的恒河猴。 目标1.为了测试在近视距（NVD）下日常执行视觉任务会导致近视转变的预测。 目标2.为了检验这一假设，即在出生后发育过程中，将观看距离限制在近处足以诱导近视转变。对于所有目的，将通过睫状肌麻痹视网膜检影术测量屈光不正，通过A扫描超声测量眼轴长度，并使用红外（IR）摄影验光测量屈光行为。在这些功能关系建立后，未来的研究将被建议检查神经机制。长期目标是了解视觉体验，眼睛生长和屈光状态之间的关系，以及指导这些关系的机制。

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. Myopia (nearsightedness) is a visual disorder that affects 25% of Americans, at a cost of $4 billion/year. It has recently been identified by NIH as a priority to address in terms of health disparities because it can disproportionately affect some minority groups. While its etiology remains unknown, studies suggest a role for genetic and environmental factors. In children, there is a higher likelihood of myopia if both parents are myopic, but also if one reads more than average. Animal models have attempted to identify the nature of the environmental influence by an emphasis on the quality of the retinal image, using form deprivation or constant defocus. The thesis of the present SCORE project is that viewing distance also influences eye growth and refractive status. Our initial studies support this assertion and we next propose to test several corollaries of the following hypothesis: prolonged exposure to visual stimuli at a near viewing distance is sufficient to induce excessive ocular elongation and relative myopia in rhesus monkeys. Aim 1. To test the prediction that daily performance of a visual task at a near viewing distance (NVD) will induce a myopic shift. Aim 2. To test the hypothesis that the restriction of viewing distance to near is sufficient to induce a myopic shift during postnatal development. For all aims, measurements of refractive error will be obtained via cycloplegic retinoscopy, measurements of axial length of the eye will be made via A-scan ultrasound, and measurements of accommodative behavior will be made using infra-red (IR) photorefraction. After these functional relationships are established, future studies will be proposed to examine neural mechanisms. The long-term goal is to understand the relationship between visual experience, eye growth, and refractive status, and the mechanisms that guide those relationships.