Experimental research of laser-induced collaterals in retinal vein occlusion

Objective: To evaluate the feasibility and safety of establishing chorioretinal venous anastomosis in rabbit eyes with a model of branch retinal vein occlusion

Methods: By using laser photocoagulation, a chorioretinal venous anastomosis was created in rabbit eyes in which a branch retinal vein occlusion had previously been established photochemically. A similar attempt to create an anastomosis was made in the control eyes in which no branch vein occlusion was present.

Results: In the 21 eyes with the model of branch retinal vein occlusion, a chorioretinal venous anastomosis formed in 4 eyes within 3 to 5 weeks. In the control eyes, an anastomosis in one eye presented by 5 weeks, during follow-up of 2 to 5 months. The hemorrhage in choroid, retina and vitreous associated with laser photocoagulation were absorbed within 3 weeks, and no other severe complications were found.

Conclusions: Chorioretinal venous anastomosis can be created by using laser photocoagulation. This technique is relatively safe. However, to improve the rate of successfully creating an anastomosis, more research work needs to be performed.