闪烁光频率对C57BL／6J小鼠近视诱导的影响

The effect of different flickering light frequencies for inducing myopia in C57BL/6 mice

目的探讨闪烁光频率对诱导C57BL／6J（B6）小鼠近视的影响。方法动物实验研究。选取双眼扈光度相近的28日龄健康B6小鼠90只，利用随机数字表法随机分为5组。实验分为3组，高频闪烁光组、中频闪烁光组、低频闪烁光组各15只小鼠分别在频率为10、5、2Hz的闪烁白色光照下饲养：对照组15只小鼠在不闪烁白色光照下饲养；形觉剥夺组30只小鼠右眼配戴半透明塑料眼罩，在不闪烁白色光照下饲养。分别于实验前、实验2周时，用红外偏心摄影验光仪测量屈光度，用A超测量眼轴长度。数据采用单因素方差分析和LsDt方法进行分析。结果小鼠屈光度和眼轴长度的变化：实验前对照组、高频闪烁光组、中频闪烁光组、低频闪烁光组、形觉剥夺组屈光度分别为（2．627±0．494）D、（2．597±0．626）D、（2．552±0．558）D、（2．617±0．568）D、（2．590±0．657）D；眼轴长度分别为（2．805±0．029）mm、（2．803±0．026）mm、（2．804±0．029）mm、（2．806±0．026）mm、（2．804±0．025）mm。实验前，5组间屈光度和眼轴长度差异均无统计学意义（F=0．073、0．077，P〉0．05）。实验2周后对照组、高频闪烁光组、中频闪烁光组、低频闪烁光组、形觉剥夺组屈光度分别为（3．720±0．555）0、（-1．71±0．632）D、（-2．020±0．705）D、（-2．612±0．686）D、（-2．873±0．6701D；眼轴长度分别为（2．924±0．022）mm、（2．995±0．024）mm、（3．000±0．020）mm、（3．017±0．029）mm、（3．026±0．01）mm。高频闪烁光组、中频闪烁光组、低频闪烁光组、形觉剥夺组屈光度和眼轴长度与对照组比较，差异均有统计学意义（F=549．172、105．718，P〈0．01），高频闪烁光组、中频闪烁光组分别与低频闪烁光组、形觉剥夺组屈光度和眼轴长度差异亦有统计学意义，其中低频闪烁光组（2Hz）和形觉剥夺组对屈光度和眼轴长度影响最显著．两组间差异无统计学意义。结论所用各频率闪烁光均能诱导小鼠近视，但以低频2Hz闪烁光诱导近视能力最强，接近于形觉剥夺。

Objective To investigate the effect of different flickering light frequencies for inducing myopia in C57BL/6 mice. Methods It was a animal experimental study. Ninety mice at age 28 days with similar refractions in both eyes were randomly assigned to five groups of 15 mice each. The control group was exposed to white non-flickering light. Three groups were exposed to white flickering lights at a high frequency, middle frequency, and low frequency at 10, 5, and 2 Hz, respectively. A form-deprivation group consisted of 30 mice that underwent monocular form-deprivation with a semitransparent hemispherical thin plastic shell covering the fight eyes, and was exposed to a non-flickering white light. Refraction and axial length were measured by murine-specific eccentric infrared photorefraction and A-scan ultrasonography at baseline and after two weeks of exposure. The data were analyzed by one way ANOVA and LSD t methods. Results （1）The change in refraction and axial length in mice： the baselines of the refractions of the control group, high frequency, middle frequency and low frequency flickering light groups and the form-deprivation group were 2.62±20.494 D, 2.597±0.626 D, 2.552±0.558 D, 2.617±0.568 D, 2.590±0.657 D, respectively. The baselines of the axial length for the corresponding groups were 2.805±0.029 mm, 2.803-20.026 mm, 2.80±20.029 mm,2.806±0.026 mm, 2.804±0.025 mm, respectively. There was no significant difference in refraction or axial length among the five groups （P〉0.05）. After 2 weeks of exposure, the refraction of the control group, the high frequency, middle frequency, low frequency flickering light groups and the form-deprivation group were 3.720±0.555 D, -1.710±0.632 D, -2.020±0.705 D, -2.612±0.686 D, -2.873±0.670 D, respectively. The axial lengths for the corresponding groups were 2.924±_0.022 mm, 2.995±0.024 mm, 3.000±0.020 mm, 3.017±0.029 mm, 3.026±0.016 mm, respectively. There was a significant difference in refraction and axial length between the control group and the other groups （P〈0.01）. However, the induced changes in refraction and axial length were greater in the low frequency flickering light group and the form-deprivation group compared to the high and middle frequency flickering light groups. Conclusion B6 mice could be induced to form myopia by flickering light at all frequencies we used, and the low frequency of 2 Hz was the most effective in inducing myopia that is equivalent to form-deprivation myopia.