An experimental model of proliferative vitretinopathy(PVR) induced by macrophages was used for the evaluation of drug efficacy of daunomycin encapsulated in liposomes in the treatment of PVR.Five mu;g daunomycin(n=40),10mu;g daunomycin-liposome(DL,n=30)and 0.1 ml saline or empty liposomes(n=40,as controls)were injected into the rabbit vitreous after macrophage injection.Retinal detachment developed in 77.5% of the control eyes on day 28,compared to 33.3% of the eyes treated with DL(P<0.01)and 50% of the daunomycin-treated eyes(P<0.05).The results suggest that encapsulation in liposomes of cytotoxic agents can enhance drug efficacy.The phasic course of development of PVR is important in the selection of particular drugs. (Chin J Ocul Fundus Dis,1993,9:77-80)