Is Retinal Processing the Key to Emmetropization?

视网膜处理是正视化的关键吗？

• 批准号: 6927828
• 负责人: CHRISTINE FRANCES WILDSOET
• 金额: $ 25.53万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-01-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6927828
• 关键词: behavioral /social science research tag; brain; chickens; choroid uvea; extraocular muscle; eye refraction disorder; growth /development; lens; light adaptations; myopia; neural information processing; optic nerve; photobiology; radial keratotomy; retina; sclera; visual feedback; visual perception; visual stimulus

DESCRIPTION (Provided by applicant): Emmetropization is the regulatory process that normally matches the optical power of the eye to its length, so that objects can be focused on the retina. Abnormalities can cause myopia (shortsightedness), in which the eye grows too long for its optical power, leading to sight-threatening complications. Refractive surgery that overcorrects myopia may lead to renewed eye growth, as may certain lighting conditions. Near-epidemic prevalence of myopia in several populations makes it critical and timely to understand the determinants of emmetropization, without which effective treatments are unlikely. Studies: The chick eye has proven to be an effective experimental model for emmetropization: many optical, surgical and pharmacological manipulations can be performed, with time and cost effectiveness, and results generalize well to mammals and primates. Our recent studies in the chick used optic nerve section (ONS) to dissociate retina and brain, and suggested that emmetropization is largely controlled locally, by the retina. Emmetropization with ONS is abnormal. We ask whether this is due to cell loss and retinal rewiring, which are side effects of ONS. Aim 1 (Role of inner retinal cells in emmetropization): We will (a) dissociate retina and brain with a ganglion cell toxin that spares certain fibers destroyed by ONS, (b) use molecular markers to test if ONS causes loss of glucagonergic amacrine cells, and (c) use growth factors to protect ganglion cells in ONS eyes. Visual stimuli are well known to affect posterior segment growth. What determines corneal growth? Aim 2 (Role of the retina in anterior segment growth): We will (a) measure effects of continuous light on corneal flattening, and consequent posterior chamber growth, (b) use radial keratotomy to control for effects of non-visually induced corneal flattening, and (c) measure intersegmental fluid exchange as a potential conduit for retinal factors that control corneal growth. It is still not known how the retina distinguishes the sign of a defocused image. Aim 3 (Decoding defocus in emmetropization): We will manipulate defocus cues with (a) reverse chromatic aberration lenses, (b) blue and red monochromatic rearing, and (c) optical control of object distance, spatial frequency, contrast, and monochromatic aberrations. Reduced retinal acuity may explain the high refractive errors in congenital outer retinal pathologies. Aim 4 (Retinal acuity & emmetropization): We will study in 3 low-acuity preparations: (a) albino chicks, (b) normal chicks reared in UV light, and (c) normal chicks reared in dim light.

描述（由申请人提供）：弹性化是监管过程 通常，这与眼睛的光学能力与其长度相匹配，以便 物体可以集中在视网膜上。异常会导致近视 （近视），其中眼睛的光学能力太长了， 导致危及视力的并发症。屈光手术 过度校正近视可能会导致眼睛生长，因为某些照明可能会导致眼睛的生长 状况。在几个人群中，近视近视流行率使它成为 至关重要的，及时了解弹性化的决定因素，而没有 哪种有效治疗不太可能。研究：小鸡的眼睛已被证明 成为弹性化的有效实验模型：许多光学，外科手术 可以按时间和成本进行药理操作 有效性，结果很好地推广到哺乳动物和灵长类动物。我们最近 小鸡的研究使用视神经段（ONS）解离视网膜和 大脑，并建议弹性化在很大程度上受到局部控制 视网膜。用ONS弹性化是异常的。我们问这是否是由于 细胞损失和视网膜重新布线，这是ONS的副作用。目标1（角色 弹性化中的内部视网膜细胞）：我们将（a）解离视网膜和 带有神经节细胞毒素的大脑，可节省某些被ONS破坏的纤维 （b）使用分子标记来测试ONS是否导致胰甘蓝型无大氨基氨酸的损失 细胞和（c）使用生长因子保护眼睛眼睛中的神经节细胞。视觉的 众所周知，刺激会影响后段生长。什么决定 角膜生长？ AIM 2（视网膜在前部段增长中的作用）：我们将 （a）连续光对角膜扁平的影响，然后 后腔生长，（b）使用径向角化术来控制 非视觉诱导的角膜扁平，（c）测量段液 交换作为控制角膜的视网膜因子的潜在管道 生长。仍然不知道视网膜如何区分 散落的图像。 AIM 3（弹性化中的解码液）：我们将 用（a）反向色差镜片操纵散焦提示，（b）蓝色 和红色单色饲养，以及（c）对象距离的光学控制， 空间频率，对比度和单色畸变。视网膜减少 敏锐度可以解释先天性外视网膜中的高折射率 病理。 AIM 4（视网膜敏锐度和弹性化）：我们将研究3 低阳性制剂：（a）白化小鸡，（b）在紫外线饲养的正常鸡 光明，（c）普通小鸡在昏暗的光线下饲养。