角膜塑形镜离焦环偏心对近视发展的影响

Influence of the decentration of the orthokeratology defocus ring on myopia

目的:探讨研究角膜塑形镜配戴后离焦环偏心对近视发展的影响。方法:选取242例验配角膜塑形镜近视患者的426眼为研究对象,按照离焦环偏心量分为正位组(n=68)、轻度偏心组(偏心量≤0.5 mm,n=117),中度偏心组(偏心量0.5~1 mm,n=164)和重度偏心组(偏心量≥1 mm,n=77)。比较不同偏心组戴镜1年后眼轴增长,分析离焦环偏心量、偏心方向与眼轴增长的关系。结果:戴镜1年后不同偏心组眼轴增长比较,差异有统计学意义(P=0.005);离焦环总偏心量、低度近视组偏心量、中度近视组偏心量与眼轴增长呈负相关(r=-0.16,P=0.002;r=-0.15,P=0.039;r=-0.21,P=0.005);偏心方向的水平夹角与眼轴增长呈负相关(r=-0.16,P=0.002)。结论:离焦环偏心量增大和向垂直方向偏移可以抑制近视发展,原因可能是其增大了视网膜部分区域近视离焦量。

Objective:To investigate the effect of the decentration of the defocus ring on the progression of myopia with orthokeratology.Methods:426 eyes of 242 patients with myopia being treated with orthokeratology were selected as the research object.According to the decentration of the defocus ring,they were divided into four groups:orthotropic group(n=68),mild decentration group(decentration≤0.5mm,n=117),moderate decentration group(decentration 0.5-1 mm,n=164)and severe decentration group(decentration≥1mm,n=77).The changes of axis length in different eccentric groups were compared,and the correlation between the distance of decentration,direction of decentration and the change in axis length after wearing the orthokeratology for 1 year were evaluated.Results:The axial length changes of different eccentric groups were significantly different(P=0.005).The total decentration,decentration in low myopia group and moderate myopia group were negatively correlated with axial growth(r=-0.16,P=0.002;r=-0.15,P=0.039;r=-0.21,P=0.005).The horizontal angle of the eccentric direction was negatively correlated with the growth of the axial length(r=-0.16,P=0.002).Conclusion:Increasing the decentration of the defocusing ring and shifting to vertical direction can inhibit the development of myopia,which may be due to enhancement of the peripheral defocusing of myopia in some areas of the retina.