近距离工作和户外活动对学龄期儿童近视进展的影响

目的：探讨近距离工作以及户外活动等对学龄期儿童近视进展的影响。方法：将80名 7~11岁的在校学生随机分入观察组（41人）和对照组（39人），指导观察组控制近、中距离工作时间30 h/周以内，增加户外活动至14~15 h/周以上，2年内定期医学验光得到屈光度，2年后由眼科医生进行问卷调查，内容包括阅读、书写、使用电脑等近距离工作时间；看电视、课外辅导等中距离工作时间；户外活动时间；使用自然光线以及每日戴镜时间等。结果：观察组儿童的年平均屈光度进展度数为0.38±0.15 D，明显低于对照组（0.52±0.19 D）（P<0.01）。观察组近距离工作时间与对照组差异无统计学意义，但看电视、课外学习等中等距离用眼时间明显短于对照组（P<0.01）。观察组户外活动时间（13.7±2.4 h/周）明显长于对照组（6.2±1.6 h/周）（P<0.01）。多元回归分析显示4个变量是减慢近视屈光度进展的主要因素：增加户外活动，增加戴镜时间，较多使用自然光，减少使用电脑时间。在观察组内，增加户外活动减慢近视进展（t=-2.510，P<0.05）；在对照组内，增加戴镜时间是减慢近视进展的主要因素（t=-3.115，P<0.05）。结论：增加户外活动，尽量使用自然光线和坚持戴镜可以减慢学龄期儿童的近视进展。

Influence of near-work and outdoor activities on myopia progression in school children

OBJECTIVE: To study the influence of near-work and outdoor activities on myopia progression in school children. METHODS: Eighty 7-11-year-old school children with myopia were randomly assigned into an intervention group (n=41) and a control group (n=39). The children in the intervention group did near- and middle-vision activities less than 30 hrs per week and more outdoor activities than 14-15 hrs per week. Myopia progression was observed regularly over 2 years after which ophthalmologists administered questionnaires regarding near-vision work (reading, writing and using computer), middle-vision work (watching TV and extracurricular learning activities), outdoor activities, using nature light, wearing glasses, etc. RESULTS: The annual mean myopia progression (0.38±0.15 D) in the intervention group was significantly lower than that in the control group (0.52±0.19 D; P<0.01). The children in the two groups spent similar amounts of time in near-vision activities, but the children in the intervention group spent less time in middle-vision activities (P<0.01) and more outdoor activities (13.7±2.4 vs 6.2±1.6 hrs/wk; P<0.01). When considering all children in the study, there were 4 factors that significantly correlated with less myopia progression: more outdoor activities, more time spent wearing glasses, more time spent in natural light and less time using a computer. When analyzing the intervention group separately, more outdoor activity was inversely correlated with myopia progression (t=-2.510, P<0.05). Separate analysis of the control group indicated that more time wearing glasses was correlated with less myopia progression (t=-3.115, P<0.05). CONCLUSIONS: Myopia progression in school children may be slowed by more outdoor activities, more time spent in natural light and more time wearing corrective glasses.