Department of Ophthalmology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan.
Ophthalmology. 2020 Nov;127(11):1462-1469. doi: 10.1016/j.ophtha.2020.01.054. Epub 2020 Feb 8.
To investigate the change in the prevalence of reduced visual acuity (VA) in Taiwanese school children after a policy intervention promoting increased time outdoors.
Prospective cohort study based on the Taiwan School Student Visual Acuity Screen (TSVAS) by the Ministry of Education in Taiwan.
All school children from grades 1 through 6 were enrolled in the TSVAS from 2001 through 2015.
The TSVAS requires each school in Taiwan to perform measurements of uncorrected VA (UCVA) on all students in grades 1 through 6 every half year using a Tumbling E chart. Reduced VA was defined as UCVA of 20/25 or less. Data from 1.2 to 1.9 million primary school children each year were collected from 2001 through 2015. A policy program named Tian-Tian 120 encouraged schools to take students outdoors for 120 minutes every day for myopia prevention. It was instituted in September 2010. To investigate the impact of the intervention, a segmented regression analysis of interrupted time series was performed.
Prevalence of reduced VA.
From 2001 to 2011, the prevalence of reduced VA of school children from grades 1 through 6 increased from 34.8% (95% confidence interval [CI], 34.7%-34.9%) to 50.0% (95% CI, 49.9%-50.1%). After the implementation of the Tian-Tian 120 outdoor program, the prevalence decreased continuously from 49.4% (95% CI, 49.3%-49.5%) in 2012 to 46.1% (95% CI, 46.0%-46.2%) in 2015, reversing the previous long-term trend. For the segmented regression analysis controlling for gender and grade, a significant constant upward trend before the intervention in the mean annual change of prevalence was found (+1.58%; standard error [SE], 0.08; P < 0.001). After the intervention, the trend changed significantly, with a constant decrease by -2.34% annually (SE, 0.23; P < 0.001).
Policy intervention to promote increased time outdoors in schools was followed by a reversal of the long-term trend toward increased low VA in school children in Taiwan. Because randomized trials have demonstrated outdoor exposure slowing myopia onset, interventions to promote increased time outdoors may be useful in other areas affected by an epidemic of myopia.
调查台湾一项增加户外活动时间的政策干预对小学生视力减退（VA）发生率变化的影响。
基于台湾教育部的台湾学童视力筛查（TSVAS）的前瞻性队列研究。
所有一至六年级的在校学生均纳入 2001 年至 2015 年的 TSVAS 研究。
TSVAS 要求台湾的每所学校每半年使用 Tumbling E 图表对一至六年级的所有学生进行未矫正视力（UCVA）测量。视力减退定义为 UCVA 为 20/25 或更差。2001 年至 2015 年期间，每年收集 120 万至 190 万名小学生的数据。2010 年 9 月，出台了一项名为“天天 120”的政策项目，鼓励学校每天让学生户外活动 120 分钟以预防近视。
视力减退的发生率。
2001 年至 2011 年，一至六年级学生视力减退的发生率从 34.8%（95%置信区间[CI]，34.7%-34.9%）增至 50.0%（95% CI，49.9%-50.1%）。“天天 120”户外活动项目实施后，发生率连续下降，从 2012 年的 49.4%（95% CI，49.3%-49.5%）降至 2015 年的 46.1%（95% CI，46.0%-46.2%），扭转了此前的长期趋势。对干预前性别和年级进行分段回归分析，发现干预前患病率平均年变化的常数呈上升趋势（+1.58%；标准误差[SE]，0.08；P<0.001）。干预后，趋势明显变化，常数每年下降 2.34%（SE，0.23；P<0.001）。
在学校推广增加户外活动时间的政策干预措施之后，台湾学童视力减退的长期趋势发生了逆转。因为随机试验已经证明户外暴露可以减缓近视的发生，所以推广增加户外活动时间的干预措施可能对其他受到近视流行影响的地区有用。
