AIM:To investigate the effects of subconjunctival gentamicin injection on rabbit retina.METHODS:Ten healthy rabbits weighted 2.0-2.5kg without binocular disorders were selected,and divided into 4 groups,3 experimental group(3 rabbits 6 eyes of each group),1 control group(1 rabbit 2 eyes).3 experimental groups received binocular subconjunctival gentamicin injection 5000μ,10000μ,20000μrespectively.Control group received binocular normal saline injection.Aqueous and vitreous fluid were extracted from these ten rabbits every day and measured the concentration with TDX/FLX.At the third day,retinas were taken to make light microscope samples in order to observe cytohistomorphology of retina,and using TUNEL to detect the apoptosis.RESULTS:The gentamicin concentration of rabbit aqueous and vitreous fluid increased as the subconjuctival injection dosage increased.Obvious pathological changes were observed in retina of experimental group.The number of apoptotic retina cells of the experimental group evidently increased than which in the control team.CONCLUSION:Subconjunctival injection of gentamicin should be prohibited in clinic for its obvious retinal toxicity.