EFFECTS OF VIEWING DISTANCE ON EYE GROWTH & REFRACTIVE DEVELOPMENT

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。虽然一个人从事近距离工作（如阅读）的时间与近视发生率之间存在显著的正相关关系，但没有直接证据表明两者之间存在因果关系，而且这种关系的本质在一个多世纪以来一直是个谜（伦理考虑排除了使用人类受试者直接通过实证研究来解决这个问题）。本项目旨在确定长时间从事近距工作是否会导致近视的发生。目标是确定一个适当的任务和行为设置，并确保光学性能是适当的。这个项目产生了一些令人兴奋的结果，这些结果被用作最近提交的NIH拨款申请的基础。简而言之，在行为任务训练开始之前，青少年恒河猴表现出稳定的屈光不正，几度远视，这是该物种的标准。在每天的实验中，猴子们在手臂够得着的电脑上进行视觉识别任务，以获得食物强化。随着时间的推移，所有3名受试者的屈光不正都发生了近视的变化，屈光不正为零或接近零。这些数据可能提供了第一个直接证据，证明长时间从事近距工作与近视的发展有关。最近，我们已经证实，在执行任务的过程中，猴子的注意力集中在电脑屏幕上，这证实了任务的光学/视觉需求与阅读相似（即集中在附近）。这个猴子模型将使我们能够确定视觉任务的哪些方面对屈光发展和近视的发展有影响，并将证明在预防近视或减少近视进展的临床努力中是有用的。

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. While there is a significant positive correlation between the amounts of time a person engages in nearwork tasks (e.g. reading) and the incidence of myopia, there is no direct evidence of a causal association, and the nature of this relationship has remained a mystery for over a century (ethical considerations preclude the use of human subjects to address this question directly through empirical research). The present project was undertaken to determine whether prolonged performance of nearwork tasks could lead to the development of myopia. The objectives were to identify an appropriate task and behavioral setup and to ensure that optical performance was appropriate. This project yielded some exciting results, which are being used as the basis for a recently submitted NIH grant application. Briefly, prior to the onset of training on the behavioral task, adolescent rhesus monkeys exhibited a stable refractive error of a few degrees of hyperopia, which is the norm for this species. In daily sessions monkeys worked for food reinforcement on a visual discrimination task displayed on a computer located within arm¿s reach (at near). Over time, all 3 subjects have undergone a myopic shift in refractive error, exhibiting zero or nearly zero refractive error. These data may provide the first direct evidence that prolonged performance of a nearwork task is associated with the development of myopia. Recently, we have verified that during the performance of the task, the monkeys are focused on the computer screen, which confirms that the optical/visual demands of the task are similar to those of reading (i.e. focused at near). This monkey model will allow us to determine what aspects of the visual task contribute to the effects of refractive development and the development of myopia and will prove useful in clinical efforts to prevent myopia or reduce its progression.