The Effects of Prematurity on Visual Development

描述(由申请人提供)：在美国，几乎每八个孩子中就有一个是早产的，但人们对这一大群孩子的视觉发育或视力损害模式知之甚少。美国儿童双眼低视力的主要原因是脑视觉障碍(CVI)，通常是由早产儿的神经损伤引起的。随着预防和治疗由极端早产引起的神经系统疾病的新疗法的出现，这种情况在不久的将来可能是可以预防的或可以治疗的。显然，需要更好的方法来测试和分析视力。否则，就没有准确的方法来判断医疗或康复干预的效果。在这项研究中，我们将测量胎龄小于32周的健康早产儿的视觉发育，并将其与足月儿进行比较。早产儿组在6、9、12个月时测量扫描VEP的光栅视力、游标敏感度和对比敏感度，足月组在3、6、9、12个月时测量。在第二个目标中，我们将在6个月、9个月和12个月时测量作为早产儿并发症的脑室出血(IVH)婴儿的这三种同样的视觉功能。这项研究的结果将提供有关正常早产儿视觉发育的重要信息，以及极端早产和神经损伤(IVH)对这种视觉发育的干扰方式。在第三个目标中，我们将评估弥散张量成像(DTI)在识别视力异常婴儿中的作用。DTI是在婴儿生命早期进行的，此时干预最有可能预防或治疗神经损伤。通过进行结构-功能分析，将儿童视力变化的频谱与他们扫描的变化频谱进行比较，我们希望能够识别出哪些儿童的视觉系统受到了损害。这将有助于及早发现视力异常，并为及早进行医疗和康复工作铺平道路。头部超声和DTI结果的比较将证明DTI是否应该取代超声在新生儿托儿所诊断神经损伤。

DESCRIPTION (provided by applicant): Nearly one in every eight children is born prematurely in the US, yet very little is known about visual development or patterns of vision damage in this large group of children. The leading cause of bilateral low vision in children in the US is cerebral visual impairment (CVI), usually caused by neurological injury in premature infants. This condition will be potentially preventable or amenable to treatment in the near future as new therapies emerge for the prevention and treatment of neurological disease that result from extreme prematurity. Clearly, better methods to test and assay vision are needed. Otherwise, there will be no accurate way to judge the effects of medical or rehabilitative intervention. In this study, we will measure visual development in healthy, premature infants less than 32 weeks gestational age, and compare this to full term infants. Sweep VEP grating acuity, vernier acuity, and contrast sensitivity measures will be obtained at 6, 9, and 12 months chronological age in the premature group, and at 3, 6, 9, and 12 months chronological age in the fullterm group. In a second aim, we will measure these same three visual functions at 6, 9, and 12 months in infants who suffer an intraventricular hemorrhage (IVH) as a complication of prematurity. Results from this study will provide important information about visual development in normal premature infants, and the manner in which such visual development is perturbed by extreme prematurity and neurological damage (IVH). In a third aim, we will evaluate the role of diffusion tensor imaging (DTI) in identifying infants with vision abnormalities. DTI is performed early in the infant's life, at a time when intervention is most likely to prevent or treat neurological damage. By performing a structure-function analysis, comparing the spectrum of acuity changes in children with the spectrum of changes on their scans, we expect to be able to identify those children who have suffered damage to their visual system. This will allow early detection of vision abnormalities and pave the way for early medical and rehabilitation efforts. A comparison of head ultrasound and DTI findings will demonstrate whether DTI should replace ultrasound for the diagnosis of neurological injury in the newborn nursery.