Analysis Of The Measurement Of Myopic Astigmatism By Corneal Topography And The Evaluation Of The Corneal Topography Application In Lasik Treatment

Objective:To explore the measurement of myopic astigmatism by corneal topography and the measured myopic astigmatism differences between corneal topography and mydriasis refraction on laser in situ keratomileusis(LASIK) preoperative and postperative and to evaluate the treatment effect of LASIK.Methods:200 eyes of 103 patients who underwent primary LASIK for myopic astigmatism in our hospital were reviewed retrospective analysis,to get the eyesight and the measurement of myopic astigmatism for preoperative and postoperative LASIK one month,three months and six months with the use of corneal topography and mydriasis refraction.The measurement of myopic astigmatism include corneal relief map shape,corneal diopter,corneal myopic astigmatism,sphere lens degree, columniation lens degree and myopic astigmatism axis.All data were analysed by using SAS software 8.0.Results:Preoperative uncorrected visual acuity averaged 0.11±0.09,preoperative best-corrected visual acuity averaged 1.12±0.13.before surgery,the degree of myopic astigmatism measured of the average mydriasis refraction was(-1.16±0.46) D,the average degree of myopic astigmatism measured of corneal topography refraction(△SimK) was(-1.01±0.57) D.The degree of myopic astigmatism measured of the first two groups was a statistically significant difference(t=4.75,P＜0.01).And the degree of axial myopic astigmatism measured of mydriasis refraction was (93.87±71.52)°,the degree of axial myopic astigmatism measured of corneal topography was(93.59±66.91)°.The degree of myopic astigmatism measured of the two groups was no statistically significant difference(t=0.17,P＞0.05).Preoperative axial myopia with astigmatism of compliance based on the regulation of those were 71%of astigmatism,against-the-rule astigmatism were 11.5%,oblique axis of astigmatism accounted for 17.5%.18～28-year-old on Regulation accounted for 72.1%of astigmatism,29～38-year-old regulations on accounting for 70.0%of astigmatism,39～49-year-old regulations on accounting for 66.7%of astigmatism. Through the regulation of men accounted for 71.3%astigmatism,astigmatism of female compliance 70.8%.6m postoperative uncorrected visual acuity in patients with the expected correction vision is in line with the rate of the array of different degrees in more than 97%.After one,three and six months of the surgery,the degree of myopic astigmatism measured of the average mydriasis refraction was(-0.60±0.27) D,(-0.61±0.34) D and(-0.59±0.25) D.The results of one,three and six months has no statistical difference(P＞0.05).The myopic astigmatism measured of corneal topography was(-0.58±0.39) D,(-0.59±0.41) D and(-0.57±0.37) D.The results of one,three and six months has no statistical difference(P＞0.05).Myopic astigmatism after 1m drop in value on average(0.46±0.52)D,myopic astigmatism after 3m drop in the average value(0.39±0.47)D,after 6m drop in the value of myopic astigmatism average(0.51±0.49)D,after preoperative myopic astigmatism with the decreased rate was 83.0%,82.9%,82.8%.The degree of axial myopic astigmatism measured of mydriasis refraction was(92.53±46.08)°,(92.58±46.10)°and(92.51±46.06)°,The results of one,three and six months has no statistical difference(P＞0.05).The degree of axial myopic astigmatism measured of corneal topography was(90.92±56.94)°,(91.13±57.01)°and(90.83±56.67)°.The results of one,three and six months has no statistical difference(P＞0.05).Straight line related analysis results that the changer of△SimK(X) and mydriasis refraction(Y) on laser in situ keratomileusis(LASIK) for preoperative and postoperative statistically correlated(r=0.56,P＜0.01).The returning to return analysis equation is:(?)=0.006 +0.486X(P＜0.01).Conclusions:(1)Before surgery,the degree of myopic astigmatism measured of corneal topography and mydriasis refraction has a statistically significant difference and the axial myopic astigmatism has no statistically significant difference.(2)Age growth,through regulation of the proportion of myopic astigmatism decreased,non-compliance of the proportion of myopic astigmatism increased.Myopic astigmatism distribution and gender has no significant correlation.(3)△SimK surgery before and after changes in the value of corneal topography (X) and clinical changes in the value of myopic astigmatism((?)),the linear regression equation:(?)=0.006+0.486X,r=0.56,P＜0.01,a positive correlation between the two tips.(4)the effect of Topography-guided LASIK surgery to correct myopic astigmatism,is stability(5)Through computer-assisted corneal topography,we can learn more about LASIK surgery before and after refractive corneal surface shape and parameters of operation to design personalized programs to predict and improve the effect of providing an important basis for surgery.