Zahidi Asma Aa, Vinuela-Navarro Valldeflors, Woodhouse J Margaret
School of Optometry & Vision Sciences, Cardiff University, Cardiff, UK.
Ophthalmic Research Group, Life and Health Sciences, Aston University, Birmingham, UK.
Clin Exp Optom. 2018 Jul;101(4):535-540. doi: 10.1111/cxo.12684. Epub 2018 Mar 30.
Visual acuity is known to be poorer in children with Down's syndrome than in age-matched controls. However, to date, clinicians do not have access to norms for children with Down's syndrome that allow differential discrimination of healthy from anomalous visual development in this population.
The Down's Syndrome Vision Research Unit at Cardiff University has been monitoring visual development in a large cohort of children since 1992. Cross-sectional data on binocular visual acuity were retrospectively analysed for 159 children up to 12 years of age in order to establish binocular acuity norms. Longitudinal binocular acuity data were available for nine children who were seen regularly over the 12 years age-range. Monocular acuity was successfully recorded less often in the cohort, but analysis of scores for 69 children allowed assessment of inter-ocular acuity differences and binocular summation.
In comparison with published norms for the various acuity tests used, binocular acuity was consistently poorer in children with Down's syndrome from the age of three years and stabilised at around 0.25 logMAR from the age of four years. Inter-ocular acuity difference and binocular summation were both 0.06 logMAR, which is similar to the reported values in children without Down's syndrome.
The study provides eye-care practitioners with the expected values for binocular acuity in children with Down's syndrome and demonstrates the visual disadvantage that children with Down's syndrome have when compared with their typically developing peers. The results emphasise the responsibility that practitioners have to notify parents and educators of the relatively poor vision of children with Down's syndrome, and the need for classroom modifications.
众所周知，唐氏综合征患儿的视力比年龄匹配的对照组儿童要差。然而，迄今为止，临床医生无法获取唐氏综合征患儿的视力标准，以便在该人群中区分正常与异常的视觉发育。
自1992年以来，卡迪夫大学的唐氏综合征视力研究单位一直在监测一大群儿童的视觉发育情况。对159名12岁及以下儿童的双眼视力横断面数据进行回顾性分析，以建立双眼视力标准。有9名儿童在12年的年龄范围内定期接受检查，可获得其双眼视力纵向数据。该队列中成功记录单眼视力的情况较少，但对69名儿童的分数进行分析，可评估两眼之间的视力差异和双眼总和。
与所使用的各种视力测试的已发表标准相比，唐氏综合征患儿从3岁起双眼视力一直较差，4岁左右稳定在约0.25 logMAR。两眼之间的视力差异和双眼总和均为0.06 logMAR，这与无唐氏综合征儿童的报告值相似。
该研究为眼科保健从业者提供了唐氏综合征患儿双眼视力的预期值，并证明了唐氏综合征患儿与正常发育的同龄人相比存在的视觉劣势。结果强调了从业者有责任告知家长和教育工作者唐氏综合征患儿视力相对较差的情况，以及对教室进行调整的必要性。
