目的:探讨角膜塑形镜( OK镜)对我国青少年低中度近视控制的有效性。方法:将青少年低中度近视患者271例271眼分为OK镜治疗组(141眼)和单光眼镜治疗组(130眼)。 OK镜治疗组平均年龄9.43±1.10岁,等效球镜度数为-2.74±1.15D;戴镜后1、7、30、90d,12mo随访。单光眼镜治疗组平均年龄9.37±1.00岁,等效球镜-2.88±1.39D,戴镜后每6 mo随访一次。观察比较OK镜组和单光眼镜治疗组眼轴增长情况。将OK镜组和单光眼镜治疗组分成小年龄组和大年龄组,进一步观察各年龄组儿童的近视发展情况。对相关数据进行配对t检验、独立样本t检验、卡方检验及Spearman相关分析。结果:OK镜组配戴角膜塑形镜1 a后,眼轴的增长值为0.27±0.17mm,与戴镜前的眼轴长度有明显统计学差异(P<0.01);单光眼镜组1a 后的眼轴增长值为0.38±0.13mm(P<0.01)。两组眼轴增长有统计学差异,且OK镜组儿童眼轴增长比单光眼镜组慢28.9%( P<0.01,独立样本t检验)。近视初始年龄与1a眼轴增长之间呈负相关(OK镜组:rs=-0.309,P<0.01;单光眼镜组:rs=-0.472,P<0.01)。小年龄儿童(7.0~9.4岁)中,眼轴增长较快(每年>0.36mm)者在OK镜组占38%,而单光眼镜治疗组则增加到76.5%;而眼轴增长较快的大龄儿童(9.4~12.0岁)在OK镜组和单光眼镜治疗组所占比例分别为24.3%和12.9%。当等效球镜( spherical equivalent refractive errors,SER)介于5.00~6.00D时,OK镜组的眼轴增长比单光眼镜组慢57.1%。结论:OK镜对控制青少年低中度近视儿童近视发展有很好的效果,儿童的近视发展随着年龄的增加逐渐减慢,而OK镜对控制小年龄儿和较高度近视发展的效果更好。
Abstract?AIM:To investigate the short-term effectiveness of orthokeratology ( ortho -k ) on controlling low -to -moderate myopic in Chinese children.?METHODS:There were 271 subjects (271 eyes) enrolled in this study.In total, there were 141 cases aged 9.43 ± 1.10 in the ortho-k group and the spherical equivalent refractive errors ( SER) were -2.74 ±1.15D.The patients were examined at 1, 7, 30, and 90d after they started wearing the ortho-k lenses.There were 130 cases aged 9.37±1.00 enrolled in the control group, with the SER-2.88± 1.39D, and the examinations occurred at 6, 12mo after they started wearing single-vision spectacles. Myopic progression was estimated from changes of axial length in both groups. The chi -square test, independent samples t-tests, paired t-tests, Spearman analysis were used to compare the data of the two groups.?RESULTS: The axial elongation was 0.27 ±0.17mm in the ortho-k group after 1a which was significantly longer than that before wearing (P<0.01); the axial elongation was 0.38±0.13mm in the control groups ( P<0.01); the difference on axial elongation between the two groups was statistically significant and the increase of axial length of the ortho-k group was significant less by 28.9% than that of the control group ( P <0.01, by independent samples t -test ) . There was significant negative correlation between axial elongation and initial age in both groups during the one-year period ( ortho-k group:rs=-0.309, P<0.01; control group: rs=-0.472,P<0.01). The percentages of younger subjects ( aged 7.0 ~9.4 ) with fast myopic progression (>0.36mm in 1a) were 38%in the ortho-k group and 76.5% in the control group, respectively;whereas those of the older group ( aged 9.4~12.0) were lower, reaching 24.3%and 12.9%in the ortho-k and control groups.In patients with SER 5.00~6.00D, the axial elongation in ortho-k group was 57.1% lower than that in control group.?CONCLUSION: Ortho-k lens is effective to control myopic progression in children with low-to-moderate myopia. In particular, it reduces the percentage of younger children with fast progression and has a better effect of controlling myopic progression with higher degrees of myopia.