Binocular Vision, Amblyopia, and Refractive Development in Esotropia

描述（由申请人提供）：婴儿和调节性内斜视（ET）影响美国2-3%的儿童，婴儿和调节性内斜视在生命的头几年破坏双眼视觉体验，并可能导致弱视和严重的永久性立体视力损害。弱视可以治疗，但由于残余弱视的复发和持续性，它仍然是年轻人中最常见的单眼视力障碍形式。我们的合作研究小组现在准备解决三个关键问题。目的1：目前关于婴儿和适应性ET的共识是，早期发现和及时干预以重新调整视觉轴可以保持正常的立体灵敏度。然而，我们最近的工作挑战了公认的范式，并使我们假设先天性的差异敏感性缺陷存在于中央视野。我们建议使用立体vep、视差收敛和适应性视差收敛来首次检验另一种假设，即在中心4 - i婴儿ET和很大一部分适应性ET儿童中存在先天性视差敏感性缺陷。这些研究将为我们提供一个新的、广泛了解婴儿双眼缺陷和适应性ET，并对早期干预的风险/收益的临床评估产生直接的转化影响。目的2：尚不清楚为什么有些ET患儿交替注视并避免弱视，而另一些患儿则倾向于单眼和弱视。基于弱视灵长类动物模型的数据和弱视婴儿和成人的视觉诱发电位抑制数据，我们假设双眼皮层相互作用抑制的不对称性可能使一些内视性婴儿和儿童易患弱视。此外，我们假设，尽管长期或反复治疗，持续性残余性弱视是由于在抑制性双目相互作用中存在强烈的不对称性，而这种不对称性在闭塞治疗中未能消除。我们建议使用一种新的方法，使我们能够量化抑制相互作用，以确定抑制中的不对称是否先于弱视，这些不对称是否在治疗有效时消退，以及持续性和复发性弱视是否是由持续的不对称抑制引起的。目的3：通过一种独特的方法来确定引导正视化的视觉信号，我们将利用一个婴儿队列，该队列与正常婴儿的初始屈光不正分布相同，但在生命的第一年没有经历正视化；即患有婴儿内斜视的婴儿。这

DESCRIPTION (provided by applicant): Infantile and accommodative esotropia (ET) affect 2-3% of children in the U.S. Infantile and accommodative ET disrupt binocular visual experience during the first years of life and may cause amblyopia and severe and permanent impairment of stereoacuity. Amblyopia can be treated but, due to recurrence and persistence of residual amblyopia, it remains the most common form of monocular visual impairment in young adults. Our collaborative research group is now poised to address three critical issues. Aim 1: Current consensus on infantile and accommodative ET is that that early detection and prompt intervention to realign the visual axes can preserve normal stereoacuity. However, our recent work challenges the accepted paradigm and has led us to hypothesize that a congenital deficit in disparity sensitivity is present in the central visual field. We propose to use stereo VEPs, disparity vergence, and accommodative disparity vergence to examine an alternative hypothesis for the first time - that there is a congenital defect in disparity sensitivity in the central 4¿ i infants with infantile ET and in a large subset of children with accommodative ET. These studies will give us a new, broad understanding of binocular deficits infantile and accommodative ET and have a direct translational impact on the clinical evaluation of the risk/benefits of very earl intervention. Aim 2: It is unknown why some children with ET alternate fixation and avoid amblyopia while others develop a preference for one eye and amblyopia. Based on data from primate models of amblyopia and visual evoked potential data on suppression in amblyopic infants and adults, our hypothesis is that asymmetry in suppressive binocular cortical interactions may predispose some esotropic infants and children to develop amblyopia. In addition, we hypothesize that persistent residual amblyopia despite prolonged or repeated treatment is due to the presence of strong asymmetry in suppressive binocular interactions that fails to diminish with occlusion therapy. We propose to use a novel method that allows us to quantify suppressive interactions to determine whether asymmetries in suppression precede amblyopia, whether these asymmetries resolve when treatment is effective, and whether persistent and recurrent amblyopia result from persistent asymmetric suppression. Aim 3: In a unique approach to determining the visual signal that guides emmetropization, we will utilize an infant cohort that shares the distribution of initial refractive errors of normal infants but failsto undergo emmetropization during the first year of life; i.e., infants with infantile esotropia. This approach will be used to identify the missing visually guided mechanism that normally stimulates axial growth to reduce infantile hyperopia. In a prospective evaluation of a preschool/school-age infantile ET cohort, we will, for the first time, examine the influence of axil and peripheral refractive error, accommodation, and ocular shape on the onset and progression of myopic axial growth in school-age children whose emmetropization had previously been inhibited. PUBLIC HEALTH RELEVANCE: Infantile and accommodative esotropia affect 2-3% of children and can cause permanent visual deficits despite prolonged or repeated treatment with eye patches, glasses, and/or surgery. Thus, the lifelong burden of visual impairment, emotional distress, and financial costs associated with infantile and accommodative ET are considerable. The goal of the project is to understand the roles of abnormal visual experience and congenital factors in leading to these visual deficits in order to facilitate the development of more effectiv prevention and treatment strategies.