Royal Women's Hospital, Melbourne, Australia.
Neuropsychol Rev. 2012 Dec;22(4):425-37. doi: 10.1007/s11065-012-9216-z. Epub 2012 Oct 12.
Preterm children are at risk for a number of visual impairments which can be important for a range of other more complex visuocognitive tasks reliant on visual information. Despite the relatively high incidence of visual impairments in this group there are no good predictors that would allow early identification of those at risk for adverse outcomes. Several lines of evidence suggest that docosahexaenoic acid (DHA) supplementation for preterm infants may improve outcomes in this area. For example, diets deficient in the long-chain polyunsaturated fatty acid DHA have been shown to reduce its concentration in the cerebral cortex and retina, which interferes with physiological processes important for cognition and visual functioning. Further, various studies with pregnant and lactating women, as well as formula-fed infants, have demonstrated a general trend that supplementation with dietary DHA is associated with better childhood outcomes on tests of visual and cognitive development over the first year of life. However, research to date has several methodological limitations, including concentrations of DHA supplementation that have been too low to emulate the in utero accretion of DHA, using single measures of visual acuity to make generalised assumptions about the entire visual system, and little attempt to match what we know about inadequate DHA and structural ramifications with how specific functions may be affected. The objective of this review is to consider the role of DHA in the context of visual processing with a specific emphasis on preterm infants and to illustrate how future research may benefit from marrying what we know about structural consequences to inadequate DHA with functional outcomes that likely have far-reaching ramifications. Factors worth considering for clinical neuropsychological evaluation are also discussed.
早产儿有许多视觉障碍的风险，这些障碍可能对一系列依赖视觉信息的更复杂的视认知任务很重要。尽管这组人群中视觉障碍的发病率相对较高，但目前还没有很好的预测指标可以早期识别那些有不良后果风险的人。有几条证据表明，给早产儿补充二十二碳六烯酸（DHA）可能会改善这方面的结果。例如，饮食中缺乏长链多不饱和脂肪酸 DHA 会导致其在大脑皮层和视网膜中的浓度降低，从而干扰认知和视觉功能的重要生理过程。此外，对孕妇、哺乳期妇女以及配方奶喂养婴儿的各种研究表明，一般来说，膳食 DHA 补充与在生命的第一年中在视觉和认知发育测试上有更好的儿童结果有关。然而，迄今为止的研究存在几个方法学限制，包括 DHA 补充的浓度太低，无法模拟 DHA 在子宫内的积累，仅使用单一的视力测量值来对整个视觉系统做出一般性假设，并且很少试图将我们对 DHA 不足的结构影响与特定功能可能受到的影响联系起来。本综述的目的是考虑 DHA 在视觉处理方面的作用，特别是针对早产儿，并说明未来的研究如何从将我们对 DHA 不足的结构后果与可能具有深远影响的功能结果结合起来中受益。还讨论了值得考虑进行临床神经心理学评估的因素。
