简介:AIM:Tostudythedistributionofocularhigher-orderaberrations(HOAs)andmesopicpupilsizeinindividualsscreenedforrefractivesurgery.·METHODS:OcularHOAsandmesopicpupilsizewerestudiedin2458eyesof1240patientswithmyopia,myopicastigmatismandcompoundmyopicastigmatismand215eyesof110patientswithhyperopia,hyperopicastigmatismandcompoundhyperopicastigmatismusingtheZywaveaberrometer(Busch&Lomb).Allpatientshadcorrectablerefractiveerrorswithoutahistoryofrefractivesurgeryorunderlyingdiseases.Root-mean-squarevaluesofHOAs,totalsphericalaberration,totalcomaandmesopicpupilsizewereanalyzed.OcularHOAsweremeasuredacrossa≥6.0mmpupil,andpupilsizemeasurementswereperformedunderthemesopiccondition.·RESULTS:ThemeanvaluesofHOAs,totalsphericalaberrationandtotalcomainthemyopicgroupwere0.369μm,±0.233,0.133±0.112μmand0.330±0.188μm,respectively.InthehyperopicgroupthemeanvaluesofHOAs,totalsphericalaberrationandtotalcomawere0.418μm±0.214,0.202±0.209μmand0.343±0.201μm,respectively.HyperopesshowedgreatertotalHOAs(P<0.01)andtotalsphericalaberration(P<0.01)comparedtomyopes.Inage-matchedanalysis,onlytheamountoftotalsphericalaberrationwashigherinthehyperopicgroup(P=0.05).Mesopicpupilsizeinthemyopicgroupwaslarger(P≤0.05).·CONCLUSION:TheresultssuggestedthatsignificantlevelsofHOAswerefoundinbothgroupswhichareimportantforplanningrefractivesurgeriesonIranians.Thereweresignificantlyhigherlevelsoftotalsphericalaberrationinhyperopescomparedtomyopes.Mesopicpupilsizewaslargerinmyopicgroup.
简介:Thekeratoprosthesis(KPro;artificialcornea)isaspecialrefractivedevicetoreplacehumancorneabyusingheterogeneousformingmaterialsfortheimplantationintothedamagedeyesinordertoobtainacertainvision.Themainproblemsofartificialcorneaarethebiocompatibilityandstabilityofthetissueparticularlyinpenetratingkeratoplasty.Thecurrentstudiesoftissue-engineeredscaffoldmaterialsthroughcomprisingcompositesofnaturalandsyntheticbiopolymerstogetherhavedevelopedanewwaytoartificialcornea.Althoughawideagreementthatthelong-termstabilityofthesedeviceswouldbegreatlyimprovedbythepresenceofcorneacells,modificationofkeratoprosthesistosupportcorneacellsremainselusive.Mostofthestudiesoncornealsubstratematerialsandsurfacemodificationofcompositeshavetriedtoimprovethegrowthandbiocompatibilityofcorneacellswhichcannotonlyreducethestimulusofheterogeneousmaterials,butalsomoreimportantlycontinuousandstablecorneacellscanpreventthedestructionofcollagenase.Thenecrosisofstromaandspontaneousextrusionofthedevice,allowformaintenanceofaprecornealtearlayer,andplaytheroleofensuringagoodopticalsurfaceandresistingbacterialinfection.Asaresult,improvementincornealcellshasbeenthemainaimofseveralrecentinvestigations;someefforthasfocusedonbiomaterialforitswellbiologicalpropertiessuchaspromotingthegrowthofcorneacells.Thepurposeofthisreviewistosummarythegrowthstatusofthecornealcellsaftertheimplantationofseveralartificialcorneas.