| Purpose:To observe the clinical results of wavefront-guided LASIK in the treatment of myopia(or with myopic astigmatism) mainly in the aspect of visual quality, and to investigate the effect of high order aberrations on visual quality.Methods:94 samples (eyes) underwent wavefront-guided LASIK were randomly selected in this retrospective analysis in our surgery center from Oct.2008 to Oct.2009. The inclusion criterions were 1) follow-up periods was more than six months and 2) the uncorrected visual acuity no less than 1.0. Mesopic contrast sensitivity function with and without glare were measured with the MesotestⅡb, photopic contrast sensitivity function with and without glare were measured with the CGT-1000, high-order aberrations were measured with VISX wavescan pre-and post-LASIK. The high-order aberrations and contrast sensitivity function pre-and post-surgery were compared to analyze the correlation between high-order aberrations and photopic contrast sensitivity function.768 samples (eyes) were enrolled in this retrospective analysis in our surgery center from Oct 2008 to Oct 2009. The inclusion criterion was spherical equivalent (SE) no more than-10.0D and follow-up periods more than one month. The samples were divided by surgery mode and degrees of SE. The uncorrected visual acuity (UCVA), residual refraction of one month, three months, six months, one year after surgery and the preoperative and postoperative data of regression samples were used for statistics.results:The results showed a statistically significant increase (P<0.05) in all high-order aberrations,z7, z8 and z12 after LASIK surgery comparing to the pre-surgery level; the photopic contrast sensitivity function with glare after surgery showed statistical significance comparing to the pre-surgery level and without glare showed on statistical significance; the mesopic contrast sensitivity function with and without glare did not degrade significantly, the pass rate of each level showed no statistical significance. All high-order aberrations and z7 showed an influence of contrast sensitivity function by comparing two groups divided by different kinds of high-order aberrations. High-order aberrations (except z9) and photopic contrast sensitivity function (4.0°spatial frequency under glare) showed statistical significance between two groups divided by pre-surgery all high-order aberrations; photopic contrast sensitivity function showed no statistical significance between two groups divided by the symbol of z7; all high-order aberrations,z7 and 0.7°spatial frequency under glare contrast sensitivity function showed statistical significance between two groups divided by pre-surgery z7 level. Analysis the post-surgery z7 level:postoperative z7=0.18-0.03 preoperative sphere. The predictability (SE<0.5D, SE<1.0D) between two groups showed no statistical significance, the residual refraction both between one month and three months and the residual refraction between three months and one year showed no statistical significances. The efficacy was 0.9984 in conventional group and 1.0067 in wavefront group. The vision change (postoperative UCVA-preoperative BSCVA) showed statistical significance between two groups, and the wavefront group was better than conventional group. Analysis the residual refraction: residual sphere (RS) was related to age and preoperative sphere, residual sphere= 1.355-0.034 age+1.142 preoperative sphere; residual cylinder was related to preoperative cylinder and preoperative center corneal thickness, residual cylinder= 3.489+0.238 preoperative cylinder-0.007 preoperative center corneal thickness.Conclusion:Wavefront-guided LASIK can induce significant amount of high-order aberrations, but the photopic contrast sensitivity function enhanced post operation under glare and reached the the pre-surgery level under no glare, mesopic contrast sensitivity function recovered quickly after surgery, and had almost reached the the pre-surgery level after six months. All high-order aberrations and z7 were the main factors which influence the visual quality post LASIK. The patients with higher level of all high-order aberrations or the lower proportion of z7 under the same all high-order aberrations were more suitable to wavefront-guided LASIK, the postoperative visual quality would be more improved (4.0°,0.7°spatial frequency under glare). Postoperative z7 has negative correlation with preoperative sphere. Varied size spot LASIK was predictable, stable, and effective for the treatment of myopia and compound myopic astigmatism, wavefront-guided LASIK was better than conventional LASIK on the aspect of predictability and efficacy, both surgery modes have a good stability; age and preoperative spherical power were risk factors for residual spherical, preoperative cylinder and preoperative center corneal thickness were risk factors for residual cylinder.
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