目的：探讨角膜塑形(OK)镜片的偏心度对眼轴和视力质量的影响。

方法：根据OK镜片偏心程度，将患者分为三组：低偏心度组(偏心度≤0.5 mm)，中偏心度组(0.5<偏心度≤1.0 mm)和高偏心度组(1<偏心度≤1.5 mm)。分析配戴OK镜后OK镜偏心程度、球面等效球镜度(SE)、未矫正视力(UCVA)、配戴OK镜前后眼轴长度(AL)、3 mm瞳孔下的总高阶像差(HOA)、彗差和球面像差(SA)。三组间各指标差异使用Kruskal-WallisH Rank分析。

结果：回顾性分析75例139眼。在低偏心组(53眼)中，平均年龄为(11.4±2.4)a，SE为(-3.24±1.48)D，AL为(24.85±1.01)mm； 中偏心组(53眼)，平均年龄(11.4±2.2)a，SE为(-3.22±1.29)D，AL为(25.15±0.92)mm； 在高偏心组(31眼)中，平均年龄为(11.5±1.9)a，SE为(-3.54±1.43)D，AL为(24.95±0.84)mm。2a后，三组间眼轴的变化无显着性差异(P=0.089)。高偏心组HOA、SA、彗差明显高于中偏心组、低偏心组(P<0.05)。

结论：OK镜配戴过程中没有必要严格要求镜片位置的绝对居中。镜片不必要的调整可能会延迟眼轴控制。另外，眼轴控制与视觉质量之间的平衡关系应进一步探讨评估。

METHODS:Based on the degree of eccentricity of OK lenses, patients were divided into three groups: a low degree of eccentricity group(degree of eccentricity ≤0.5 mm), a group of moderate eccentricity(eccentric degree >0.5-≤1.0 mm)and a group with a high degree of eccentricity(eccentric degree >1-≤1.5 mm). The degree of eccentricity of the OK lens, spherical equivalent(SE), the uncorrected visual acuity after wearing OK lenses(UCVA), axial length before and after wearing OK lenses(AL), total higher-order aberrations(HOA), comas, and spherical aberrations(SA)for 3 mm pupils were analyzed. The difference among the three groups for all parameters was compared using the Kruskal-Wallis H Rank-Sum test.

RESULTS:The study retrospectively analyzed 75 cases(139 eyes). In the low eccentricity group(53 eyes), the mean age was 11.4±2.4 years, SE was -3.24±1.48 D, and AL was 24.85±1.01 mm. In the moderate eccentricity group(53 eyes), the mean age was 11.4±2.2 years, SE was -3.22±1.29 D, and AL was 25.15±0.92 mm. In the high eccentricity group(31 eyes), the mean age was 11.5±1.9 years, SE was -3.54±1.43 D, and AL was 24.95±0.84mm. After two years, there was no significant difference in the changes of the axis among the three groups(P=0.089). The HOA, SA, and coma in the high eccentric group were significantly higher than in the middle eccentric group(P<0.05). The HOA, SA, and coma in the high eccentric group were also significantly higher than those in the low eccentric group(P<0.05).

CONCLUSION:For OK lenses, it is unnecessary to strictly require the absolute centralization of the lens position. An unnecessary change of the lenses may delay the eye-axis control. However, the balance between axial control and visual quality should be assessed.