Effects Of FS-LASIK In The Treatment Of High Myopia Adjusted Cutting Diopter During Operation

BackgroundFS-LASIK is a refractive surgery method which uses femtosecond laser to assisted making valve and excimer laser to complete stromal layer' cutting.It is one of the mainstream refractive surgery methods.Most excimer laser instruments have found that with the increase of refraction,the degree of post-operative correction is more serious.Does SCHWIND AMARIS 500 E excimer laser also have this problem? How to adjust the operation plan? The purpose of this study is to explore an optimal surgical design by adjusting the cutting refraction and observing the refractive state after the operation of Zimer femtosecond laser and SCHWIND AMARIS 500 E excimer laser in the treatment of high myopia.ObjectiveTo observe the effects of Femtosecond Laser-assisted Excimer laser in situ Keratomileusis(FS-LASIK)in the treatment of high myopia adjusted cutting diopter and to find the best adjustment scheme of the cutting refraction.MethodFrom March 2018 to May 2018,120 eyes of high myopia patients in the First affiliated Hospital of Xinxiang Medical University Ophthalmology treated with FS-LASIK were selected,including 64 males and 56 females.Only right eyes were included in the study.Age 18-35(22.29±4.08)years.Group A whose spherical equivalent ?-6.00 D and <-7.00 D had 32 eyes,in which 16 eyes were totally corrected and the other 16 eyes' cutting diopter subtracted-0.25 D.34 eyes in Group B whose spherical equivalent ?-7.00 D and <-8.00 D,in which 19 eyes' cutting diopter subtract-0.25 D and the others 19 eyes' cutting diopter-0.50D;Group C whose spherical equivalent ?-8.00 and <-9.00 D had 26 eyes,in which 14 eyes' cutting diopter subtracted-0.50 D while the other 12 eyes' cutting diopter subtracted-0.75 D.Group D whose spherical equivalent ?-9.00 and <-10.00 D had 28 eyes,in which 15 eyes' cutting diopter subtracted-0.75 D while the other 13 eyes' cutting diopter subtracted-1.00 D.The naked visual acuity and diopter of all patients were collected 1 month,3 months and 6 months after operation.T-test was used to compare the difference of naked vision and residual diopter between different designs.ResultsSCHWIND AMARIS 500 E excimer laser also has overcorrection in the treatment of high myopia,and the degree of overcorrection will also increase with the increase of myopia.There were significant differences of the naked visual acuity and diopter at each time point between totally corrected and cutting diopter subtracted-0.25 D in group A(P < 0.05);There were significant differences of the naked visual acuity and diopter at each time point between cutting diopter subtracted-0.25 D and-0.50 D in group B(P < 0.05).There were significant differences of the naked visual acuity and diopter at each time point between cutting diopter subtracted-0.50 D and-0.75 D in group C(P < 0.05).There were significant differences of the naked visual acuity and diopter at each time point between cutting diopter subtracted-0.75 D and-1.00 D in group D(P < 0.05).Combined with the naked visual acuity and diopter at each time point after the operation,the following can be observed: a satisfactory naked visual acuity and diopter could be obtained when the preoperative equivalent spherical lens number was ?-6.00 D and <-7.00 D,?-7.00 D and <-8.00 D,?-8.00 D and <-9.00 D,?-9.00 D and <-10.00 D,the cutting diopter of the patient was subtracted by-0.25 D,-0.50 D,-0.75 D and-1.00 D during the operation,respectively.The postoperative diopter were all between-0.25 D and +0.50 D,and the uncorrected visual acuity can reach the best corrected visual acuity before operation.ConclusionIn the treatment of high myopia with SCHWIND AMARIS 500 E excimer laser,the degree of overcorrection increased with the increase of myopia.It is feasible to adjust the amputation diopter properly to reduce the occurrence of postoperative overcorrection in the treatment of high myopia.