EFFECTS OF VIEWING DISTANCE ON EYE GROWTH & REFRACTIVE DEVELOPMENT

这个子项目是众多研究子项目之一

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.