The experimental study of the effect of medicine-induced posterior vitreous detachment on proliferative vitreoretinopathy

Abstract

Objective To observe the effect of medicine-induced posterior vitreous detachment (PVD) on proliferative vitreoretinopathy (PVR).Methods.PVR was induced in the left eyes of 24 pigmented rabbits by intravitreal injection with platelet rich plasma.The rabbits were randomly divided into two experimental groups (group A and B) and one control group with 8 eyes in each group.Three hours later,the eyes in group A and B and the control group underwent intravireal injection with 1 U plasmin 0.05 ml+ 20 U hyaluronidase 0.05 ml,plasmin 0.1 ml,and balance salt solution 0.1 ml,respectively.The grade of PVR was recorded 1,7,and 28 days after the intravitreal injection,and the eyes were examined by flash electroretinogram (FERG),B-scan,and retinal histopathological examination.Results The PVR models of rabbit eyes were induced successfully.On the 7th day after injection,complete and partial PVD was found in 5 and 3 eyes respectively in group A;partial PVD in 5 eyes and no complete PVD was observed in group B;there was no PVD in the other 3 eyes in group B and also in the eyes in the control group.On the 28th day after intravitreal injection,PVR grade of group A and B were both obviously lower than that of the control group(D= 75.6,98.9;P = 0.003,P = 0.011) ;On the 7th and 28th day after injection,the b-wave amplitude in group A and B was significantly higher than that in the control group;PVR grade of the PVD eyes was lower than that of non-PVD eyes;PVR grade of the complete PVD eyes was only 0 ～ 1.Conclusions Three hours after the PVR models of rabbit eyes were induced,complete PVD induced by intravitreal injection of plasmin combined with hyaluronidase could prevent the development of PVR of rabbit eyes in some degree;partial PVD induced by plasmin alone or combined with hyaluronidase could relieve the development of PVR. Key words: Vitreoretinopathy,proliferative; Vitreous detachment; Plasmin/administration dosage; Hyaluronoglucosaminidase/administration & dosage; Animal experimentation