| Objective:To investigate the effects of liposome-encapsulated 5-Fu on proliferative vitreoretino -pathy(PVR)in pigmented rabbits.Methods:32 pigmented rabbits were randomly divided into one control group(n=8)and 3 experimental groups(A,B and C),PVR was induced in pigmented rabbits by intravitreal injection of platelet rich plasma.On the 2th day after PVR was induced,the eyes received an intravitreal injection of 0.1mg 5-Fu(0.1ml)in group A,0.1mg,0.4mg liposome-encapsulated 5-Fu(0.1ml)and equivalent dose of balanced salt was injected to the eyes of group B,C and control group respectively.The eyes were examined ophthalmoscopieally on distinct days before and after the intravitreal injection,and the stage of PVR was evaluated.Results:(1)Slit-lamp examination:there were no obvious abnormity in anterior segment of eye among the control group and group A,group B.In group C,posterior lens capsule of eyes began to opacificate on 10th day after intravitreal injection.Eye lens weren't completely clear on 35th day.(2)Stage of PVR:observation by ophthalmosope showed that except on 35d after intravitreal injection,PVR stage of group B was lower than that of the control group and group A,and the difference between group B and group A or the control group gave statistical meaning(P＜0.05), there were no significant differences among groups on other days(7d,14d,21d and 35 d after injection).(3)Flash-Electroretinogram(F-ERG)recordings:Repeated measurement data on 1d before injection and on 1d after injection showed that there was no significant difference among groups (P＞0.05).On 14 d after injection,there were statistical differences among all groups(P＜0.05) (the b-wave amplitude B:106.58±34.66,C:78.91±8.35,A:65.60±26.37,control group: 45.52±16.50).On 35 d after injection,the b-wave amplitude in group B(100.65±34.42)was significantly higher than that in the control group(21.23±11.50),group A(41.63±20.64)and group C(40.51±8.23).Except between group C with group A,there were significant differences among groups(P＜0.05).(4)B-scan ultrasound observation:With time process,the development of PVR in group A and control group was quicker than group B and group C.On 14 d after injection,the retina in group A and the control group thickened significantly.There was some proliferative membrane in vitreous in group B and group C.On 35d,In front of the retina there was thick proliferative membrane in group A and the control group,retinas of five eyes had extensive detachment respectively.In group B and group C the retina thickened slightly,retinas of two eyes had limited detachment in group B,not in group C(5)Histopathologic observation:On 14d after injection,in group A and the control group, fibrous hyperplasia and mitochondria could be seen obviously in the inner limiting membrane and in the nerve fiber layer,mitochondria had edema and vacuolar degenera- tion;retina in group B and group C had the complete structure,few fibers could be seen in the inner limiting membrane of retina,part of the mitochondria in the inner segment had light edema.On 35d after injection,In group A and the eontrol group,Large sum of proliferative membrane could be seen on the detached retina,structure of retina was destroided;some fibers could be seen in the proliferative membrane in group B,mitochondria in the inner segment had edema.In group C, the arrangement of retina was serious disordered,the structure of inner limited membrane is disappear,fiber proliferated on the surface of proliferative membrane,mitochond -ria in the inner segment seriously destroyed,outer segment membrane disk was deformed and distortedConclusions:(1)Intravitreal injection of 0.1mg liposome-encapsulated 5-Fu has certain therapeutic effect in the proliferative vitreoretinopathy(PVR)in experimental rabbit model and does not have obvious toxicity for retina.Its effect is prior to equivalent dose of 5-Fu.(2)Intravitreal injection of 0.4mg liposome-encapsulated 5-Fu can inhibit the developme -nt of PVR,but it has toxicity for retina.. |
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