Clinical Study Of Combined Wavefront-guided Laser In Situ Keratomileusis And Aspheric Ablation Profile For Myopic Astigmatism

Part 1:Clinical study of outcomes of combined wavefront-guided laser in situ keratomileusis and aspheric ablation profile for myopic astigmatismPurpose: To explore the safety,effectiveness,predictability,stability and its impact on visual quality of combined wavefront-guided laser in situ keratomileusis and aspheric ablation profile for myopic astigmatismMethods: 60 patients(120 eyes)with myopic astigmatism who underwent combined wavefront-guided laser in situ keratomileusis and aspheric ablation in Shenzhen Second People’s Hospital from January 2015 to June 2015 were selected,including 35 males and 25 females with an average age of 28.21±4.52 years old.The preoperative Spherical lens was-4.37±1.52 D,the average astigmatism was 1.43± 1.03 D,and the average spherical equivalent was-5.05±1.42 D.Preoperative examination included uncorrected distance visual acuities,corrected distance visual acuities,manifest and cycloplegic refraction,external eye examination;slit lamp evaluation of ocular surface and anterior segment,posterior and peripheral fundus examination,tonometry,corneal thickness measurement,corneal topography(Orbscan,Bausch & Lomb),contrast Sensitivity(CSV-1000,Vector vision,USA),wavefront measurement(Zywave,Bausch & Lomb),dry eye examnation;pupil diameter measurement(Zywave,Bausch & Lomb).Patients were followed at 1 day,1 week,1 month,3 months,6 months,12 months after surgery.Routine examination included uncorrected distance visual acuities,corrected distance visual acuities,slit lamp,fundus,intraocular pressure,contrast sensitivity,corneal topography,wavefront measurement,etc.And record the complications during and after surgery.Statistical analysis was performed using PASW Statistics 19.0 statistical software.Results: 1.Complications: There were no intraoperative complications and postoperative complications in this study.2.Efficacy: Postoperative uncorrected distance visual acuities was significantly better than that before surgery(P =0.01).At 12 months postoperative,the mean Log MAR was-0.07 ±0.04,the proportion of eyes with uncorrected distance visual acuity of 20/20 or better was 91%,the proportion of eyes with uncorrected distance visual acuitiy of 20/32 or better was 99%,and the proportion of eyes with uncorrected distance visual acuity of 20/40 or better was 100%.At 12 months postoperative,93% postoperative uncorrected distance visual acuity equal to or exceeded preoperative corrected distance visual acuities.The percent of uncorrected distance visual acuities within 1 line of preoperative corrected distance visual acuities was 99%.The efficacy index was 1.01.3.Safety: Compared the corrected distance visual acuity before and after surgery.No one lost 2 lines of corrected distance visual acuity.6% eyes lost 1 line of corrected distance visual acuity.45% eyes have no change of corrected distance visual acuity,40% eyes gain one line and 9% eyes gain two lines of corrected distance visual acuity postoperatively.The safety index is 1.16.4.Predictability: Postoperative spherical equivalent was significantly decreased than before surgery(P =0.01).No obvious undercorrection or overcorrection was found(spherical equivalent exceeded ±1D).The spherical equivalent at 12 months after surgery was-0.06 ± 0.05 D.92% eyes were within ± 0.5D,and 100% eyes were within± 1.0D.5.Stability: 2% eyes had change in postoperative spherical equivalent refraction of >0.50 D from 3 to 12 months.The difference was not statistically significant(P =0.61).6.High-order aberrations: The mean preoperative total high order aberration was 0.39 ± 0.18μm.The mean postoperative total high order aberration was 0.40 ± 0.15μm at 12 months after surgery,the difference was not statistically significant(P =0.55).The mean preoperative spherical aberration was 0.18 ± 0.08μm.Mean postoperative spherical aberration 12 months after surgery was 0.22 ± 0.14 μm.The difference was not statistically significant(P =0.32).The total high order aberrations remained unchanged or decreased in 48 eyes(70.3%).There were no significant differences in horizontal coma,vertical coma,and trefoil before and after surgery(P=0.06,0.07,0.06).7.Vector analysis of astigmatism: Preoperative astigmatism in 0.5D accounted for 34%,in the 1.0D accounted for 58.7%.At 12 months postoperatively,astigmatism in the 0.5D accounted for 87%,in 1.0D accounted for 98.7%.The average TIA is 1.43 ± 1.03 D,and the average SIA is 1.60 ± 1.16 D.The two are highly correlated,with a correlation coefficient of 1.094 and an average CI of 1.10.Postoperative AE averaged-4.1±3.9 degree.AE accounted for 49% in the range of 5 degrees,and AE accounted for 82% in the range of 15 degrees.8.Contrast sensitivity: The preoperative spatial frequencies of 3,6,12 and 18c/d were 1.65 ± 0.10,1.81 ± 0.15,1.59 ± 0.14,1.41 ± 0.11,respectively,and 1.69 ± 0.12,1.80± 0.16,1.61 ± 0.15,1.40 ± 0.13 postoperatively.The contrast sensitivity of different spatial frequencies before and after surgery was not statistically significant(P=0.08,0.07,0.07,0.07).Conclusion: Combined wavefront-guided laser in situ keratomileusis and aspheric ablation ablation profile is safe,effective,predictable and stable for treatment of myopia astigmatism.It also shows good postoperative visual quality.Part 2: Comparative study of combined wavefront-guided laser in situ keratomileusis and aspheric ablation profile and aspherical ablation for myopiaPurpose: To compare the clinical effects of combined wavefront-guided laser in situ keratomileusis and aspheric ablation profile and aspherical ablation for myopia.Methods: Forty patients(80 eyes)with myopic astigmatism who underwent LASIK surgery in Shenzhen Second People’s Hospital from June 2015 to December 2015 were selected.All of them can understand and sign the Informed Consent Form,willing and able to perform post-operative follow-up schedules.There were 15 males and 25 females with an average age of 26.28±3.72 years.The preoperative spherical lens was-4.82±1.42 D,the mean astigmatism was-0.46±0.41 D,and the mean spherical equivalent was-5.01±1.30 D.All patients were randomized into two groups,one receiving combined wavefront-guided laser in situ keratomileusis and aspheric ablation and the other receiving aspheric LASIK.Results: 1.All patients completed 12 months of follow-up.A total of 20 patients(40 eyes)received combined wavefront-guided laser in situ keratomileusis and aspheric ablation and the others(40 eyes)received aspheric LASIK.In the combined wavefront-guided laser in situ keratomileusis and aspheric ablation group,the preoperative spherical lens was-4.79±1.62 D,the average astigmatism was-0.42±0.36 D,the mean spherical equivalent was-5.02±1.41 D,and the average diameter of optical zone was 6.5±0.31 mm.The aspherical LASIK group had a preoperative spherical lens of-4.85±1.31 D,an average astigmatism of-0.52±0.41 D,the mean spherical equivalent was-5.00±2.01 D,and the average diameter of optical zone was 6.3±0.42 mm.There was no significant difference between the two groups in general data(P>0.05).2.Efficacy: The uncorrected distance visual acuity of the two groups was significantly better than that before surgery(P=0.00,0.01).The mean Log MAR in the combined wavefront-guided laser in situ keratomileusis and aspheric ablation group was-0.08±0.05 at 12 months after operation,and the mean Log MA in the aspheric LASIK group was-0.07±0.06.There was no significant difference between the two groups(P =0.60).In the combined wavefront-guided laser in situ keratomileusis and aspheric ablation group,the proportion of eyes with uncorrected distance visual acuity of 20/20 or better was 92%.The proportion was 90% in the aspheric LASIK group.The difference was not statistically significant(P =0.66).The efficacy index of the two groups was 0.92(combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.89(aspheric LASIK group).3.Safety: There were no intraoperative complications and postoperative complications in two groups.No one lost 2 lines of corrected distance visual acuity in two groups.2.5% eye in both of two groups lost 1 line of corrected distance visual acuity.58% eyes have no change of corrected distance visual acuity in the combined wavefront-guided laser in situ keratomileusis and aspheric ablation group.67.5% eyes have no change of corrected distance visual acuity in the aspheric LASIK group and the difference was statistically significant(P =0.03).The percent of eyes gain one line of corrected distance visual acuity postoperatively is 27%(combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 25%(aspheric LASIK group),respectively,and the difference was not statistically significant(P =0.32).The percent of eyes gain two or more lines of corrected distance visual acuity postoperatively is 12.5%(combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 5%(aspheric LASIK group),respectively,and the difference was statistically significant(P =0.01).The Efficacy index of the two groups was 1.15(combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 1.14(aspheric LASIK group)4.Predictability: Postoperative spherical equivalent of two groups was significantly decreased than before surgery(P =0.01,0.00).The spherical equivalent of the two groups at 12 months after surgery were-0.27 ± 0.16D(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and-0.21 ± 0.19D(Aspheric LASIK group)respectively,and the difference was not statistically significant(P =0.17).In the combined wavefront-guided laser in situ keratomileusis and aspheric ablation group,91% eyes were within ± 0.5D,and 100% eyes were within± 1.0D.In the aspheric LASIK group,90% eyes were within ± 0.5D,and 100% eyes were within± 1.0D.The difference was not statistically significant(P =0.33).No obvious undercorrection or overcorrection above 1D was found in two groups.5.Stability: 5% eyes had change in postoperative spherical equivalent refraction of >0.50 D from 3 to 12 months in combined wavefront-guided laser in situ keratomileusis and aspheric ablation group.7.5% eyes had change in postoperative spherical equivalent refraction of >0.50 D from 3 to 12 months in aspheric LASIK group.The difference was not statistically significant(P =0.21).6.Higher-order aberrations: The total high-order aberrations of the two groups before surgery were 0.41±0.18μm(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.39±0.15μm(Aspheric LASIK group),and the difference was not statistically significant(P =0.48).The mean postoperative total high order aberration was 0.48 ± 0.24 μm(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.62 ± 0.21 μm(Aspheric LASIK group),the difference was statistically significant(P = 0.01).The mean preoperative spherical aberration was 0.16 ± 0.08 μm(Combined wavefront-guidedlaser in situ keratomileusis and aspheric ablation group)and 0.17 ± 0.07 μm(Aspheric LASIK group),and the difference was not statistically significant(P =0.32).The mean postoperative spherical aberration was 0.17 ± 0.11 μm(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.16 ± 0.12 μm(Aspheric LASIK group),and the difference was not statistically significant(P =0.22).The mean preoperative coma aberration was 0.08 ± 0.07 μm(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.08 ± 0.03 μm(Aspheric LASIK group),and the difference was not statistically significant(P =0.18).The mean postoperative coma aberration was 0.07 ± 0.03 μm(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 0.08 ± 0.03 μm(Aspheric LASIK group),the difference was statistically significant(P =0.01).7.Contrast sensitivity: The spatial sensitivity of the two groups before surgery was 1.50 ± 0.12,1.61 ± 0.15,1.61 ± 0.14,1.48 ± 0.11(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 1.47± 0.11,1.59 ± 0.12,1.60 ± 0.15,1.48 ± 0.09(Aspheric LASIK group),the difference was not statistically significant(P=0.12,0.20,0.18,0.10).The spatial sensitivity of the two groups at 12 month after surgery was 1.60± 0.12 、 1.71± 0.15 、 1.58± 0.11 、 1.41± 0.12(Combined wavefront-guided laser in situ keratomileusis and aspheric ablation group)and 1.57± 0.11、1.65± 0.12、1.30± 0.12、1.28± 0.03(Aspheric LASIK group).The difference of 3c/d spatial frequency between two groups was not statistically significant(P =0.11).And the difference between two groups in spatial frequencies at 6,12 and 18c/d was statistically significant(P = 0.00,0.01,0.00)Conclusions: Both combined wavefront-guided laser in situ keratomileusis and aspheric ablation profile and aspherical ablation are effective for myopia.Combined wavefront-guided laser in situ keratomileusis and aspheric ablation ablation profile can reduce postoperative aberration and improve visual quality more efficiently than aspheric ablation.