经上皮准分子激光角膜切削术对角膜前表面参数的影响

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。

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

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.