Development and Maintenance of Binocular Vision (EY005236)

描述（由申请人提供）：先天性和早发性双目失衡，包括内斜视（ET）和白内障影响美国2-4%的婴儿。视力发育过程中的双目失衡有可能导致弱视和双眼视力异常。超过90%的先天性和早发性双眼失衡患者需要遮挡治疗、眼镜矫正和/或手术，许多患者需要反复干预。双眼感觉功能异常与多发眼肌手术、游离性垂直偏差、潜伏性眼球震颤和弱视的高风险相关。因此，早期双眼失衡的代价是显著的。在目前的资助期间，我们发现双眼视力最初在婴儿ET中正常发育，但被异常的双眼经验所破坏。这一结果表明，早期手术可能会预防这种缺陷，但是，尽管我们发现在早期手术后立体视的患病率较高，但正常的立体视锐度很少。我们建议通过研究婴儿ET与最初正常的粗外周视差敏感性发育有关，但先天缺乏或不可逆的中央视野视差敏感性异常的假设来追求这一令人惊讶的结果。此外，我们将调查先天性中心视差敏感性缺陷是否与婴儿ET的聚光异常有关。我们目前的几项研究支持双眼功能障碍和弱视之间的联系。我们将检验以下假设：不对称的双眼相互作用使一些内斜视婴儿和儿童易患弱视；停止遮挡治疗可减少不对称；持续残余弱视是不对称抵抗治疗的结果。对3岁以下儿童弱视的了解相对较少。在即将到来的资助期，我们将描述生命前3年弱视的自然史，确定在这个年龄段是否存在不同的治疗反应模式和与治疗相关的不同风险，并评估婴幼儿弱视检测和监测的新方法。虽然我们已经很好地掌握了单侧剥夺性弱视的影响和致密先天性单侧白内障的治疗方案，但其他类型的白内障对发育中的视觉系统的影响仍然存在一些重要的问题。我们建议定义致密性先天性双侧白内障视力结果的关键时期，检查部分白内障对视力成熟的影响，并评估致密性先天性白内障儿童眼运动发育的关键时期。综上所述，这五个目标直接解决了NEI国家计划的既定目标，即“调查弱视和斜视高危儿童的视觉功能发展，确定潜在机制，并开发和传播有关检测方法和恢复正常视力的治疗干预措施的信息。”公共卫生相关性：先天性和早发性双眼失衡，如内斜视和白内障，影响美国2-4%的婴儿。超过90%的先天性和早发性双眼失衡患者需要遮挡治疗、眼镜矫正和/或手术，许多患者需要反复干预。本研究的目的是确定正常双眼视力发展的必要和充分条件，并提高先天性和早发性双眼视力不平衡患者的治疗效果。

Description (provided by applicant): Congenital and early onset binocular imbalance, including esotropia (ET) and cataracts affect 2-4% of infants in the U.S. Binocular imbalance during visual development has the potential to cause amblyopia and abnormalities in binocular vision. Over 90% of patients with congenital and early onset binocular imbalance require occlusion therapy, spectacle correction, and/or surgery, and many require repeated interventions. Abnormal binocular sensory function is associated with higher risk for multiple eye muscle surgeries, dissociated vertical deviation, latent nystagmus, and amblyopia. Thus, the cost of early onset binocular imbalance is significant. During the current grant period, we found that binocular vision initially develops normally in infantile ET but is disrupted by abnormal binocular experience. This result suggested that very early surgery might prevent the deficit but, although we found a higher prevalence of stereopsis after very early surgery, normal stereoacuity was rare. We propose to pursue this surprising result by investigating the hypothesis that infantile ET is associated with initially normal development of the coarse, peripheral disparity sensitivity but a congenital absence or irreversible abnormality of the disparity sensitivity in the central visual field. Furthermore, we will investigate whether a congenital deficit in central disparity sensitivity is associated with vergence abnormalities in infantile ET. Several of our studies during the current grant support a link between binocular dysfunction and amblyopia. We will test the hypotheses that asymmetric binocular interactions predispose some esotropic infants and children to develop amblyopia, that weaning from occlusion therapy acts to diminish asymmetry, and that persistent residual amblyopia results from asymmetry that resists treatment. Relatively little is known about amblyopia in children <3 years of age. In the upcoming grant period, we will characterize the natural history of amblyopia during the first 3 years of life, determine whether different patterns of response to treatments and different risks associated with treatments are present in this age range, and evaluate new approaches to the detection and monitoring of amblyopia in infants and young children. While we have a good grasp on the effects of unilateral deprivation amblyopia and treatment protocols for dense congenital unilateral cataracts, a number of important questions remain about the effects of other types of cataracts on the developing visual system. We propose to define the critical period for visual acuity outcome in dense congenital bilateral cataracts, examine the effects of partial cataracts on visual maturation, and evaluate the critical period(s) for ocular motor development in children with dense congenital cataracts. Taken together, these five Aims directly address a stated goal of the NEI National Plan, namely "to investigate the development of visual function in children at high risk for amblyopia and strabismus, determine underlying mechanisms, and develop and disseminate information about detection methods and therapeutic interventions for restoring normal vision." PUBLIC HEALTH RELEVANCE: Congenital and early onset binocular imbalance due, for example, to esotropia and cataracts affect 2-4% of infants in the U.S. Over 90% of patients with congenital and early onset binocular imbalance require occlusion therapy, spectacle correction, and/or surgery, and many require repeated interventions. The aim of the proposed studies is to define the necessary and sufficient conditions for the development of normal binocular vision and to enhance treatment outcomes of patients with conditions that are associated with congenital and early onset binocular imbalance.