Intravitreal and subretinal injection of tissue plasminogen activator (tPA) in the treatment of experimentally created retinal vein occlusion in rabbits

Abstract

Purpose: To evaluate the effectiveness of intravitreal or subretinal injection of tPA in the treatment of experimentally created retinal vein occlusion (RVO) in rabbits.

Methods: Fifteen rabbits were included in this study. RVO was created in all using an argon green laser following intravenous injection of rose Bengal. Follow-up examinations included color fundus photography, fundus fluorescein angiography, and optical coherence tomography. Following examinations at day 2, animals were divided into three groups: six rabbits were kept as control, four rabbits received subretinal injection of tPA, and five rabbits received intravitreal tPA.

Results: Of 14 eyes that had capillary drop out at day 2 following creation of RVO, 12 remained the same at week 3. Only one eye in the control group and one eye in the subretinal group developed complete reperfusion of capillaries. Although there was more revascularization in all groups at week 3, there was not a significant difference in the amount of revascularization between the control group and those animals receiving subretinal or intravitreal tPA.

Conclusion: Intravitreal or subretinal injection of tPA 2 days following vein occlusion did not improve reperfusion of retinal vessels in experimentally created RVO in rabbits when compared to control group.