Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
Ophthalmology. 2012 Oct;119(10):2141-51. doi: 10.1016/j.ophtha.2012.04.020. Epub 2012 Jul 17.
To summarize relevant evidence investigating the association between time spent outdoors and myopia in children and adolescents (up to 20 years).
Systematic review and meta-analysis.
Results from 7 cross-sectional studies were pooled in a meta-analysis. A further 16 studies (8 cross-sectional not meeting criteria for meta-analysis; 7 prospective cohort studies; 1 randomized, controlled trial [RCT]) were reported in the systematic review.
The literature search included 4 databases (Medline, Embase, Web of Science, and Cochrane Central Register of Controlled Trials [CENTRAL]), and reference lists of retrieved studies. Estimates of association were pooled using random effects meta-analysis. We summarized data examining the association between time spent outdoors and prevalent myopia, incident myopia, and myopic progression.
Pooled odds ratios (ORs) and 95% confidence intervals (CIs) for myopia for each additional hour spent outdoors per week from a meta-analysis.
The pooled OR for myopia indicated a 2% reduced odds of myopia per additional hour of time spent outdoors per week, after adjustment for covariates (OR, 0.981; 95% CI, 0.973-0.990; P<0.001; I(2), 44.3%). This is equivalent to an OR of 0.87 for an additional hour of time spent outdoors each day. Three prospective cohort studies provided estimates of risk of incident myopia according to time spent outdoors, adjusted for possible confounders, although estimates could not be pooled, and the quality of studies and length of follow-up times varied. Three studies (2 prospective cohort and 1 RCT) investigated time spent outdoors and myopic progression and found increasing time spent outdoors significantly reduced myopic progression.
The overall findings indicate that increasing time spent outdoors may be a simple strategy by which to reduce the risk of developing myopia and its progression in children and adolescents. Therefore, further RCTs are warranted to investigate the efficacy of increasing time outdoors as a possible intervention to prevent myopia and its progression.
总结户外活动时间与儿童和青少年近视（20 岁以下）之间相关性的相关证据。
系统评价和荟萃分析。
荟萃分析中汇总了 7 项横断面研究的结果。系统评价中还报告了另外 16 项研究（8 项不符合荟萃分析标准的横断面研究；7 项前瞻性队列研究；1 项随机对照试验[RCT]）。
文献检索包括 4 个数据库（Medline、Embase、Web of Science 和 Cochrane 中央对照试验注册库[CENTRAL]）和检索研究的参考文献列表。使用随机效应荟萃分析汇总关联的估计值。我们总结了数据，以检查户外活动时间与近视现患率、近视发病率和近视进展之间的关系。
荟萃分析中每周户外活动每增加 1 小时，近视的汇总优势比（OR）和 95%置信区间（CI）。
调整协变量后，每周户外活动每增加 1 小时，近视的汇总 OR 表明近视的几率降低 2%（OR，0.981；95%CI，0.973-0.990；P<0.001；I²，44.3%）。这相当于每天增加 1 小时户外活动时间的 OR 为 0.87。3 项前瞻性队列研究根据户外活动时间提供了近视发病率的风险估计值，这些估计值是在调整了可能的混杂因素后得出的，尽管无法对这些估计值进行汇总，而且研究的质量和随访时间长短各不相同。3 项研究（2 项前瞻性队列研究和 1 项 RCT）研究了户外活动时间与近视进展的关系，发现增加户外活动时间可显著减少近视进展。
总体研究结果表明，增加户外活动时间可能是降低儿童和青少年近视风险及其进展的一种简单策略。因此，有必要进行进一步的 RCT 研究，以调查增加户外活动时间作为预防近视及其进展的一种可能干预措施的疗效。
