AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent t...AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent the FS-LASIK from April 2022 to November 2022 were included.They were divided into three groups according to the ratio of residual corneal stroma thickness/corneal thickness(RCST/CT):Group I(50%≤RCST/CT<55%,63 eyes of 32 patients),Group II(55%≤RCST/CT<60%,67 eyes of 34 patients),and Group III(RCST/CT≥60%,67 eyes of 34 patients).The intraocular pressure(IOP),corneal compensated IOP(IOPcc),corneal hysteresis(CH)and corneal resistance factor(CRF)were measured immediately,1,and 3mo postoperatively by ocular response analyzer(ORA)and the posterior elevation difference(PED)was measured by Pentacam.RESULTS:After operation,IOP,CH,CRF,and PED were statistically different among the three groups(F=12.99,31.148,23.998,all P<0.0001).There was no statistically significant difference in IOPcc among the three groups(F=0.603,P>0.05).The IOP,IOPcc,CH,and CRF were statistical changed after surgery(F=699.635,104.125,308.474,640.145,all P<0.0001).The PED of Group I was significantly higher than that of Group II(P<0.05),and Group II was significantly higher than that of Group III(P<0.05).The PED value of 3mo after surgery decreased in each group compared with 1mo after surgery,but there was no statistical difference(Group I:t=0.82,P=0.41;Group II:t=0.17,P=0.87;Group III:t=1.35,P=0.18).The correlation analysis of corneal biomechanical parameter changes with PED at 1mo and 3mo after surgery showed thatΔIOP,ΔIOPcc,ΔCH,andΔCRF were not correlated with PED value in three groups(P>0.05).CONCLUSION:The smaller the RCST/CT,the greater effect on corneal biomechanics and posterior surface elevation.There is no correlation between changes in corneal biomechanics and posterior corneal surface elevation in the range of RCST/CT≥50%.展开更多
AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 3...AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 30.6±8.9y).Prior to treatment and an average 7mo after therapy,Scheimpflug analysis was performed using Pentacam HR.In addition to corneal thickness assessments,corneal radius,elevation,and aberrometric measurements were performed both on anterior and posterior corneal surfaces.Data obtained before and after surgery were statistically analyzed.RESULTS:In terms of horizontal and vertical corneal radius,and central corneal thickness no deviations were observed an average 7mo after operation.Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces.During follow-up period,no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.CONCLUSION:Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces,elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus.展开更多
目的研究准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)术后角膜后表面高度的改变及其相关影响因素。方法对52例(102眼)近视及近视散光患者施行LASIK手术,分别于术前、术后第1个月、第3个月应用Pentacam眼前节分析系...目的研究准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)术后角膜后表面高度的改变及其相关影响因素。方法对52例(102眼)近视及近视散光患者施行LASIK手术,分别于术前、术后第1个月、第3个月应用Pentacam眼前节分析系统检测角膜后表面高度的变化。采用SPSS13.0统计软件进行分析,数据之间两两比较应用配对t检验,角膜后表面高度及高度差与其他因素之间的相关性应用Pearson相关分析。结果手术后第1个月和第3个月,角膜后表面高度分别为(7.21±5.60)μm和(7.27±4.98)μm,与手术前比较,差异有统计学意义(t=-4.033,-4.745;P=0.000,0.000);术后第1个月和第3个月角膜后表面高度的差异无统计学意义(t=-0.179,P=0.859)。术后第1个月和第3个月,角膜后表面前移量分别为(1.61±4.19)μm和(1.74±3.67)μm,两者的差异无统计学意义(t=-0.315,P=0.754)。后表面高度变化分别与手术前屈光度、切削量、切削比、RBT、RBT/CCT有明显相关性(P<0.05)。结论LASIK手术后角膜后表面部分前移,但变化量微小。屈光度越高,切削量越多,RBT保留越少,角膜后表面向前膨隆的程度越大。随着时间的延长,角膜后表面高度变化呈稳定趋势。展开更多
文摘AIM:To investigate the changes in corneal biomechanics and posterior corneal surface elevation after femtosecond laser-assisted in situ keratomileusis(FS-LASIK).METHODS:Totally 197 eyes of 100 patients who underwent the FS-LASIK from April 2022 to November 2022 were included.They were divided into three groups according to the ratio of residual corneal stroma thickness/corneal thickness(RCST/CT):Group I(50%≤RCST/CT<55%,63 eyes of 32 patients),Group II(55%≤RCST/CT<60%,67 eyes of 34 patients),and Group III(RCST/CT≥60%,67 eyes of 34 patients).The intraocular pressure(IOP),corneal compensated IOP(IOPcc),corneal hysteresis(CH)and corneal resistance factor(CRF)were measured immediately,1,and 3mo postoperatively by ocular response analyzer(ORA)and the posterior elevation difference(PED)was measured by Pentacam.RESULTS:After operation,IOP,CH,CRF,and PED were statistically different among the three groups(F=12.99,31.148,23.998,all P<0.0001).There was no statistically significant difference in IOPcc among the three groups(F=0.603,P>0.05).The IOP,IOPcc,CH,and CRF were statistical changed after surgery(F=699.635,104.125,308.474,640.145,all P<0.0001).The PED of Group I was significantly higher than that of Group II(P<0.05),and Group II was significantly higher than that of Group III(P<0.05).The PED value of 3mo after surgery decreased in each group compared with 1mo after surgery,but there was no statistical difference(Group I:t=0.82,P=0.41;Group II:t=0.17,P=0.87;Group III:t=1.35,P=0.18).The correlation analysis of corneal biomechanical parameter changes with PED at 1mo and 3mo after surgery showed thatΔIOP,ΔIOPcc,ΔCH,andΔCRF were not correlated with PED value in three groups(P>0.05).CONCLUSION:The smaller the RCST/CT,the greater effect on corneal biomechanics and posterior surface elevation.There is no correlation between changes in corneal biomechanics and posterior corneal surface elevation in the range of RCST/CT≥50%.
文摘AIM:To compare the anterior and posterior corneal parameters before and after collagen cross-linking therapy for keratoconus.METHODS:Collagen cross-linking was performed in31 eyes of 31 keratoconus patients(mean age 30.6±8.9y).Prior to treatment and an average 7mo after therapy,Scheimpflug analysis was performed using Pentacam HR.In addition to corneal thickness assessments,corneal radius,elevation,and aberrometric measurements were performed both on anterior and posterior corneal surfaces.Data obtained before and after surgery were statistically analyzed.RESULTS:In terms of horizontal and vertical corneal radius,and central corneal thickness no deviations were observed an average 7mo after operation.Corneal higher order aberration showed no difference neither on anterior nor on posterior corneal surfaces.During follow-up period,no significant deviation was detected regarding elevation values obtained by measurement in mm units between the 3.0-8.0 mm-zones.CONCLUSION:Corneal stabilization could be observed in terms of anterior and posterior corneal surfaces,elevation and higher order aberration values 7mo after collagen cross-linking therapy for keratoconus.
文摘目的研究准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)术后角膜后表面高度的改变及其相关影响因素。方法对52例(102眼)近视及近视散光患者施行LASIK手术,分别于术前、术后第1个月、第3个月应用Pentacam眼前节分析系统检测角膜后表面高度的变化。采用SPSS13.0统计软件进行分析,数据之间两两比较应用配对t检验,角膜后表面高度及高度差与其他因素之间的相关性应用Pearson相关分析。结果手术后第1个月和第3个月,角膜后表面高度分别为(7.21±5.60)μm和(7.27±4.98)μm,与手术前比较,差异有统计学意义(t=-4.033,-4.745;P=0.000,0.000);术后第1个月和第3个月角膜后表面高度的差异无统计学意义(t=-0.179,P=0.859)。术后第1个月和第3个月,角膜后表面前移量分别为(1.61±4.19)μm和(1.74±3.67)μm,两者的差异无统计学意义(t=-0.315,P=0.754)。后表面高度变化分别与手术前屈光度、切削量、切削比、RBT、RBT/CCT有明显相关性(P<0.05)。结论LASIK手术后角膜后表面部分前移,但变化量微小。屈光度越高,切削量越多,RBT保留越少,角膜后表面向前膨隆的程度越大。随着时间的延长,角膜后表面高度变化呈稳定趋势。
