The Protective Effects On The Function And Structure Of Retinae In Diabetiic Rats By Intravitreal Injection Of Ciclosporin A

Objective：To investigate the electrophysiological and morphological changes ofretinae after intravitreal injection of ciclosporin A（CsA） in experimentaldiabetic rats.Methods：Experimental study.SD diabetic mellitus（DM） rat models wereinduced with intraperitoneal injection of streptozotocin. The rats weredivided into four groups，with9rats in each group：the normal control（group CON），the diabetic rats with or without ciclosporin A intravitrealinjection respectively（group DM+CsA and Group DM），and the diabeticrats with dimethyl sulfoxide （DMSO） intravitreal injection （groupDM+DMSO）.The intravitreal injection of CsA or contrast solution wasperformed4weeks after the modeling.The retinal function of rats was examined by electroretinogram（ERG）48hours after the intravitrealinjection.All rats were sacrificed and the structural changes of retina wereobserved by optical and transmission electron microscope. The datas ofERG including amplitudes and latencies of a-wave and b-wave, wereanalysised by One-way ANOVA.Results：The ERG a-wave and b-wave amplitudes of DM rats weredeclined.The a-wave and b-wave amplitudes of Group DM+CsA weresignificantly increased compare to the other two groups （bothP<0.05）.Under optical microscope，Group DM，DM+DMSO and DM+CsAhad outer nuclear layer（ONL） disorder.Under transmission electronmicroscope， there were ultrastructure changes of the threegroups.Furthermore，the ONL disorder and ultrastructure changes of GroupDM+CsA were less severe than the other two groups.Conclusions：Functional and morphological changes are evident in the early stagesin DM rats.Intravitreal injection with ciclosporin A showed protectiveeffects on the nerve function in DM retina.