Corneal Refractive Surgery And Visual Quality

Objective:The RMS values of corneal surface aberration and whole eye aberration were measured before and after the corneal refractive surgery using Sirius corneal topography instrument and Wavescan wavefront aberration instrument.Analysis the relationship of anterior corneal surface aberration、the whole eye aberration and diopter before surgery;the changes of anterior and posterior corneal surface high-order aberrations and optic aberrations;the changes of contrast sensitivity after Wavefront -guide corneal refractive surgery.Methods:This was a retrospective study.74 patients (144 eyes) were reruited before wavefront-guide corneal refractive surgery from April 2013 to August 2015. All the subjects underwent the following examinations including mean spherical equivalent (SE)、anterior corneal Aberration. (Sirius, CSO)、total aberration (Wavefront Analyzer, VISX)、contrast sensitivity (CSV-1000E). The RMS of AOA、HOA、Coma、Trefoil、 Sph、Z3-1、Z31 were collected and the anterior corneal and total aberration measurements were performed in the eyes with 6mm pupil diameter. The values of contrast sensitivity were measured preoperation and at the third month postoperation. (2) The values of each component of the total and anterior corneal high-order aberration in the central 6mm area were calculated. paired sample t-test、independent sample t-test and Pearson correlation analysis were performed using SPSS software(SPSS 17.0), The statistical significance was set to the P<0.05 level。The conversion formula for diffirent pupil:Results:1.The significant differences were found between the whole aberration (HOA、Coma、Trefoil、Sph) and the value of anterior corneal (all P <0.05). Z3-1 and Z31 had no differences between the whole eyes and anterior corneal.2.The myopia diopter and the anterior corneal surface aberration AOA、 HOA、Coma、Trefoil、Sph、Z3-1、Z31 had no significant correlations (P> 0.05) in the two group of SE<-6.00D and SE>-6.00D; In the groups of SE<-6.00D and SE>-6.00D,they had significant correlations (P<0.01) between the diopter and the AOA of whole eyes,the other aberations but spherical of whole eyes had no significant correlations. (P> 0.05).3.All the aberrations of anterior and posterior corneal and whole eyes were increased postoperation. There were statistically significant differences (P<0.05) between the aberrations preoperation and postoperation. All the aberrations of anterior and posterior corneal and whole eyes had no statistically significant differences between any time-points from 1 month to 1 year. The increment of all the high-order aberration but spherical had no obvious difference between anterior corneal and whole eyes.4.All of the aberrations of anterior corneal were increased both in the groups of wavefront-guide and without wavefront-guide corneal refractive surgery.The increment of coma in the wavefront-guide group was less than that in the. There were statistically significant differences (P<0.05) between the two group and other aberration had no significant differences (p>0.05).All the aberrations of whole eyes were also increased both in the two groups.The increment of HOA、Coma、Sph and Z3-1 in the wavefront-guide group were less than that in the without wavefront-guide group and there were statistically significant differences (P<0.05),but the Trefoil and Z31 ad no significant differences (P>0.05).5.The area under the curve of contrast sensitivity and the spatial frequency contrast sensitivity were significantly improved in the eyes of contrast sensitivity lower than the normal preoperative at the third month in the bright、glaring and dark environment o There were statistically significant differences (P<0.05) comparing with preoperative,and the improvement of contrast sensitivity was the most significant in condition of glaring.6.In the condition of bright、glaring and dark, the optic aberrations of the eyes of contrast sensitivity lower than the normal preoperative were increased at the third month postoperative,it was increased most significantly in the dark environment and increased least in the glaring condition.7.In the condition of bright、glaring and dark, the average of optic aberrations in the eyes with contrast sensitivity lower than the normal preoperative were greater than the average of all the eyes, but there was no significant statistical difference (p>0.05).Conclusion:1. Intraocular Higher-order aberrations HOA, Coma, Trefoil and Sph of myopia patients maybe compensated the anterior corneal higher-order aberrations and it coulde reduce the whole eye aberration. The higher-order aberrations Z3-1 and Z31 maybe had compensation and additive effectson between Intraocular and anterior corneal; The diopters had no significant effect on the corneal aberrations, but had most significant effect on lower order aberrations of the whole eye and sph of higher-order aberrations.2.Not only the higher-order aberrations of anterior corneal but also the higher-order aberrations of posterior corneal and whole eyes were increased significantly after wavefront-guided corneal refractive surgery.Due to the change of eyes’adjustment ability and other reasons, Intraocular higher-order aberrations except the higher order aberrations of posterior corneal would significant changes postoperative. The compensation of intraocular higher-order aberrations and anterior corneal higher-order aberrations still existed and would be stranger, so that the increment of higher-order aberrations of whole eye was less than that of anterior corneal.3.The eyes of lower contrast sensitivity has a relatively high total ocular higher-order aberrations preoperative. The wavefront-guided refractive surgery could be significantly reduced the increment of ocular wavefront aberrations and made the spatial frequency improved significantly postoperative. Contrast sensitivity improved most significant in glaring condition,It maybe has relationship with pupil size.Because the pupil was bigger in the glaring condition. Comprehensive above factors we consider wavefront-guided -corneal refractive surgery could reduce the increment of ocular high-order aberration significantly and was beneficial to the improvement of the visual quality postoperative.