【摘要】 【目的】探讨准分子激光原位角膜磨镶术(LASIK)前后角膜非球面特点及其对术后视觉质量的影响。【方法】前瞻性对本中心接受LASIK患者26例50眼进行随访研究,检测指标包括OrbscanⅡz角膜地形图(提供角膜非球面因子Q值)、波前像差、对比敏感度(contrast-sensitivity function,CSF)、裸眼视力、最佳矫正视力、最佳矫正球镜度;分析时段为术前及术后3月,分析手术前后角膜非球面因子Q值分布,Q值与高阶像差以及高阶像差与对比敏感度的关系。【结果】术前Q值为-0.17±0.11;术后Q值为0.84±0.41,两者存在统计学差异(P=0.01)。术前Q值与术前球差成负相关(P=0.000,r=-0.578),与高阶像差成正相关(P=0.047,r=-0.333)。手术前后Q值改变与球差改变成负相关(P=0.000,r=-0.588),与高阶像差改变成正相关(P=0.001,r=0.566)。术后3月无眩光、低、中、高度眩光对比敏感度均较术前降低,但无统计学差异(P>0.05)。高阶像差改变与术后无眩光各空间频率对比敏感度6.3,4.0,2.5,1.6,1.0,0.7(cycles per degree,cpd)成负相关(P<0.05);高阶像差改变与低、中、高度眩光对比敏感度中高频空间频率6.3,4.0,2.5,1.6cpd成负相关(P<0.05),与低频空间频率(1.0,0.7cpd)无相关关系(P>0.05)。【结论】近视性LASIK使角膜由伸长型(长椭球体)椭球体演变为扁平型椭球体(扁椭球体),并影响术后视觉质量。更多还原

【Abstract】 [Objective] To investigate the asphericity after laser in situ keratomileusis and the effect of postsurgery asphericity on visual function.[Methods] In a prospective case series, 26 patients(50 eyes) with myopia or myopic astigmatism who had LASIK were evaluated. Topography which offer Q value, high order aberration,contrast-sensitivity function(CSF), uncorrected visual acuity(UCVA), best spectacled-corrected visual acuity(BSCVA), refraction were observed before and 3 months after surgery. The relationships between Q value, high order aberration and contrast-sensitivity function were analyzed. [Results] The Q value was significantly increase from -0.17±0.11 to 0.84±0.41 after surgery.There was a negative relationship between Q value and spherical aberration, a positive relationship between Q value and high order aberration preoperatively. The increase Q value was negative related to the increase spherical aberration,positive related to the increase high order aberration. The CSF measurement deteriorated after LASIK,the change was no significant(P >0.05). There was a negative relationship between the increase high order aberration and the non-glare CSF at all frequencies of 6.3,4.0,2.5,1.6,1.0 and 0.7 cycles per degree(P< 0.05). There was a negative relationship between the increase high order aberration and low,moderate, high degree glare CSF at frequenciey of 6.3,4.0,2.5 and 1.6 cycles per degree(P< 0.05). [Conclusion] The corneal asphericity changes from prolate to oblate after LASIK for myopia. The corneal asphericity changes following LASIK is a factor in the functional vision decrease.更多还原