经上皮准分子激光角膜切削术对角膜前表面参数的影响

Clinical observation of transepithelial photorefractive ketatectomy on the anterior corneal surface parameters

目的:观察经上皮准分子激光角膜切削术(TPRK)对角膜曲率、非球面性参数(Q值)及像差的影响。方法:选取行TPRK手术治疗并随访6mo以上的近视患者29例58眼,Pentacam行术前和术后检查。分析术前和术后6mo时1~8mm直径曲率、目标曲率和术后3mm环曲率,Q值和角膜像差。结果:1~8mm范围,角膜曲率术后比术前各范围均有显著性降低。术后3mm环曲率39.20±1.99D,手术目标曲率39.51±1.99D,两者呈显著相关(r=0.98)。术前术后Q值分别为-0.44^-0.30、0.34~0.66(P<0.05)。术前和术后角膜总高阶像差、球差、垂直彗差分别为0.41±0.10、0.17±0.08、-0.07±0.23和0.72±0.23、0.41±0.17、-0.24±0.32,术后有显著性增加;手术前后水平彗差分别为-0.03±0.12、-0.03±0.30(P>0.05)。结论:TPRK手术后角膜曲率显著性降低,3mm区域的变化量最大;术后Q值、角膜总高阶像差、球差和垂直彗差均显著性增加。

AIM:To observe the effect of transepithelial photorefractive ketatectomy(TPRK)on corneal curvature,asphericity and aberrations.METHODS:Twenty-nine patients(58 eyes)were enrolled.The 1mm-8mm zone curvature,target curvature and 3mm ring curvature,corneal asphericity(Q value)and corneal aberration was measured and analyzed before and 6mo after TPRK surgery.RESULTS:In the 1mm-8mm zone,the corneal curvature all had significant decrease after TPRK surgery.The curvature 3mm ring after operation was 39.20±1.99D,and the curvature target was 39.51±1.99D.And both values had a significant correlation(r=0.98).The Q values before and after operation were-0.44 to-0.30,0.34-0.66 respectively(P<0.05).The total high-order aberration,spherical aberration and vertical coma of cornea before and after operation were 0.41±0.10,0.17±0.08,-0.07±0.23 and 0.72±0.23,0.41±0.17,-0.24±0.32,respectively,and these differences were significant.The pre-and postoperative horizontal coma was-0.03±0.12,and-0.03±0.30 respectively(P>0.05).CONCLUSION:After TPRK operation,corneal curvature decreased significantly,and the change in zone of 3mm was the largest.The Q value,total high-order aberration,spherical aberration and vertical coma increased significantly after TPRK operation.