简介：AIM:Toevaluatechangesintheanteriorchamberdepth(ACD),crystallinelensthickness(LT)anditsrefractivepowerafterlaserinsitukeratomileusis(LASIK).·METHODS:Inallcases,thepreoperativeandpostoperativecentralACDwhichweremeasuredwithPentacam,Orbscan,IOL-MasterandA-scanultrasonography,centralcornealtruenetpowerwhichwasmeasuredwiththePentacam,OrbscanandIOL-Master,axiallength(AL)whichwasmeasuredwithIOL-MasterandLTwhichwasmeasuredwiththeA-scanultrasonographywerecomparedusingthepairedsamplettest.OcularrefractiveerrorsandlensrefractivepoweratcornealplanewerecalculatedandtheircorrelationswerealsoevaluatedbeforeandafterLASIK.RESULTS:At1weekafterLASIK,LTandcrystallinelensrefractivepoweratcornealplane(Dlens)whichwereassociatedwiththeIOL-MasterandPentacamincreasedsignificantly(P≤0.005),ACDdecreasedsignificantly(P≤0.001),butnosignificantincreasewasobservedintheDlenswhichwasassociatedwiththeOrbscan(P=0.261).SignificantcorrelationsbetweenthechangesintheocularrefractiveerrorsandDlenswhichwereassociatedwiththePentacamwereobservedat1weekand6monthsafterLASIK(P=0.028;P=0.001).CONCLUSION:LTincreasedsignificantlyafterLASIK,andthismightpartiallyleadtoACDdecrease,Dlensincreaseandasmallquantityofmyopicregression.

简介：AIM:Todescribethecharacteristicsofmodulationtransferfunction(MTF)ofanteriorcornealsurface,andobtainthethenormalreferencerangeofMTFatdifferentspatialfrequenciesandopticalzonesoftheanteriorcornealsurfaceinmyopes.·METHODS:Fourhundredeyesfrom200patientswereexaminedunderSIRIUScornealtopographysystem.PhoenisanalysissoftwarewasappliedtosimulatetheMTFcurvesofanteriorcornealsurfaceatverticalandhorizontalmeridiansatthe3,4,5,6,7mmopticalzonesofcornea.TheMTFvaluesatspatialfrequenciesof5,10,15,20,25,30,35,40,45,50,55and60cycles/degree(c/d)wereselected.·RESULTS:TheMTFcurveofanteriorcornealsurfacedecreasedrapidlyfromlowtointermediatefrequency(0-15cpd)atvariousopticalzonesofcornea,thevaluedecreasedto0slowlyathigherfrequency(>15cpd).Withtheincreaseoftheopticalzonesofcornea,MTFcurvedecreasedgradually.3)Intherangeof3mm-6mmopticalzonesofthecornea,theMTFvaluesmeasuredathorizontalmeridianweregreaterthanthecorrespondingvaluesathorizontalmeridianofeachspatialfrequency,thedifferencewasstatisticallysignificant(P<0.05).At7mmopticalzonesofcornea,theMTFvaluesmeasuredathorizontalmeridianwerelessthanthecorrespondingvaluesatverticalmeridianat10-60spatialfrequencies(cpd),andthedifferencewasstatisticallysignificantin25,30,35,40,45,50cpd(P<0.05).·CONCLUSION:MTFcanbeusedtodescribetheimagingqualityofopticalsystemsatanteriorcornealsurfaceobjectivelyindetail.