AIM:ToexploretheinhibitoryeffectofasustainedcyclosporinA(CsA)deliverymicrosphere(CsA-MS)onposteriorcapsularopacification(PCO)inrabbiteyesaftercataractextraction.·METHODS:TwentyNewZealandwhiterabbitsacceptedcataractextractionplusintraocularlensimplantationandtheirlefteyeswereintraoperativelyinjectedCsA-MSpreparedusingpolymerpolylactioglycolicacid(PLGA)asacarrierandtheirrighteyeswereinjectedwithemptyMS.Thechangesincornea,anteriorchamberreaction,intraocularpressure,PCOandCsAconcentrationinaqueoushumorwereexaminedpostoperativelyandalltheeyeswereenucleated3monthsaftersurgeryforhistopathologicalandmorphologicalexaminationwithlightmicroscopyandelectronmicroscopy.·RESULTS:Conjunctivalhyperemia,cornealedema,intraocularpressureandanteriorchamberresponseofexperimentalandcontroleyesweresimilar,whilePCOinCsAMSinjectedeyeswasgreatlyimprovedcomparedwiththatincontroleyes.PosteriorcapsulesinCsA-MSinjectedeyesweresmoothandlensepithelialcells(LEC)didnotproliferatesignificantly(P>0.05),whileLECinposteriorcapsuleofcontroleyeshaddifferentdegreesofproliferationandcorticalregeneration.LECinCsA-MSinjectedeyeswerenotfunctionallyactiveandunderwentapoptosis,whereasLECincontroleyeswerefunctionallyactive(F-test,P=0.025).Inaddition,thecornealultrastructureshowednodifferencesbetweenCsA-MSandMSinjectedeyes.CONCLUSION:CsA-MShashighbioavailabilityinrabbiteyesandcouldinhibitpostoperativePCOoccurrenceanddevelopmentduringthestudyperiod,suggestingthatCsA-MSmaybeapromising,effectiveandsafeadministrationroutetopreventPCOinclinic.
