目的：比较兔眼球后Tenon囊下灌注和玻璃体腔注射bevacizumab后玻璃体和血清中的浓度，并观察bevacizumab视网膜荧光显影，探讨bevacizumab球后Tenon囊下灌注的眼内通透性和眼外给药途径的可行性。

方法：实验用健康成年新西兰兔20只，随机分为A组和B组，A组均单眼接受单次玻璃体腔注射1.25mg bevacizumab(1.25mg/0.05mL)，B组均单眼单次Tenon囊下灌注5mg bevacizumab(5mg/0.2mL)。1、3d后抽取玻璃体和血液，使用双抗体夹心Elisa检测玻璃体和血清中bevacizumab药物浓度，比较两组中玻璃体和血清内bevacizumab浓度差异，并通过激光共聚焦观察视网膜免疫荧光。

结果：给药1d后，A组和B组玻璃体腔内bevacizumab药物浓度分别为254.40±13.65、1.60±0.32μg/mL。A组和B组血清内bevacizumab药物浓度分别为0.55±0.15、0.63±0.05μg/mL，两组血清bevacizumab浓度比较差异无统计学意义(t=1.168，P=0.277)。给药3d后，A组和B组玻璃体腔内bevacizumab药物浓度分别为236.80±8.70、1.40±0.23μg/mL，A组和B组血清内bevacizumab药物浓度分别为0.66±0.17、0.64±0.14μg/mL，两组血清内bevacizumab浓度比较差异无统计学意义(t=0.207，P=0.841)，两种给药方式视网膜各层荧光分布均能明显显现。

结论：给药1、3d后玻璃体腔注药组在玻璃体腔内bevacizumab药物浓度要明显高于Tenon囊下灌注组，玻璃体腔内注射是较为有效的给药途径，而球后Tenon囊下灌注也能使bevacizumab进入玻璃体腔而且达到完全抑制VEGF活动所需的浓度(>500ng/mL)，并能至少持续3d以上，两种给药方法在血清中均能检测到较高浓度的bevacizumab，且两者浓度差异无统计学意义(P>0.05)，两种给药方式视网膜各层荧光分布均能明显显现，提示两种给药方式药物均能作用于视网膜各层。

AIM:To compare the concentration of Bevacizumab in serum and vitreous after bevacizumab administered by retrobulbar Tenon capsule perfusion and intravitreal injection in eyeballs of rabbits and observe the fluorescence of retinal, and to investigate the intraocular permeability of bevacizumab after retrobulbar Tenon capsule perfusion feasibility of extraocular administration route.

METHODS: Twenty healthy adult New Zealand rabbits were used in the study. The rabbits were randomly divided into two groups, group A received single administration of 1.25mg bevacizumab(1.25mg/0.05mL)by intravitreal injection, group B received single administration of 5mg bevacizumab(5mg/0.2mL)by retrobulbar Tenon capsule perfusion. Bevacizumab concentrations in serum and vitreous were determined by double antibody sandwich Elisa at 1 and 3d after administration. The changes of bevacizumab concentrations in serum and vitreous of two groups were compared, and the fluorescence of retinal was observed by laser confocal microscope.

RESULTS: One day after administration, intravitreal concentrations of bevacizumab in vitreous of group A and B were 254.40±13.65 and 1.60±0.32μg/mL respectively. Concentrations of bevacizumab in serum of group A and B were 0.55±0.15 and 0.63±0.05μg/mL respectively. The changes of bevacizumab concentrations in serum between two groups did not vary significantly(t=1.168, P=0.277). At 3d after administration, concentrations of bevacizumab in vitre-ous of group A and B were 236.80±8.70 and 1.40±0.23μg/mL respectively. Concentrations of bevacizumab in serum of group A and B were 0.66±0.17μg/mL and 0.64±0.14μg/mL respectively. The changes of bevacizumab concentrations in serum between two groups did not vary significantly(t=0.207, P=0.841). For two administration routes, the fluorescence distribution of retina layers could be clearly detected.

CONCLUSION: At 1 and 3d after intravitreal injection, intravitreal concentrations of bevacizumab of group A is much higher than that of group B. Intravitreal injection of bevacizumab is the more effective route of administration for intraocular tissue. But retrobulbar Tenon capsule perfusion can also achieve the minimum concentration which can completely blocks VEGF activity(>500ng/mL), and can remain for at least three days. Both intravitreal injection and retrobulbar Tenon capsule perfusion of bevacizumab results in high serum concentration, and the change of bevacizumab concentration in serum between two groups does not vary significantly. In both administration routes, the fluorescence distribution of retina layers can be clearly detected, and both two dosing ways can work on each layer of retina.

宁波市科技局自然科学基金(No.2010A610033)