Laser-induced Chorioretinal Venous Anastomosis For Retinal Vein Occlusion By Means Of ICGA

Laser-induced chorioretinal venous anastomosis may bypass the occluded vein and relieve the venous obstruction. It is the best therapy for retinal vein occlusion (RVO)in theory. It remains controversial and unproven. Whether this technigue becomes applied extensively. To expound the factors of improving anastomosis formation, in our study, Laser-induced chorioretinal anastomosis was created by means of Indocynine Green Angiography (ICGA) for treatment of RVO. According of ICGA, the laser anastomosis spot was positioned on the area which a large underlying choroidal vein passes through or closes to the retinal vein, this will promote the rate of successful anastomosis, decrease anastomosis risk. There is no report about this respect.To evaluate objectively clinical effect of this new method, a control group would be compared with laser anastomosis group.METHODS1. Patients :63 cases with ophthaltnoscopic and angiographic evidence of RVO were divided in two groups randomly:37 cases (37eyes)study group; 26 cases (26 eyes ) control group.2. Before treatments, some examination was obtained, including of visual acuity, funduscopyx colour fundus photographs, fluorescein angiogram (FFA) and ICGA.2ooi3. selected anastomosis site:The site for the attempt at anastomosis creation was chosen at least 2-3 disc diameters (DD)away from the optic disc or 1 disc diameter peripheral to the occlusion site in eyes with bruch retinal vein occlusion (BRVO), and a large underlying choroidal vein by showing in ICGA, usually in the inferior fundus. The position for an anastomosis creation would be avoided the posterior choroidal arteries ?In this way, 33 sites(38%)were chosen. If chosen site was blurred by hemorrhage or ICGA could not show choroidal vein clearly, the laser site was at convenient area?There were 53 sites(62%) which were not located by ICGA.4. The creation of a laser-induced chorioretinal anastomosis:High-power density laser was applied to selected location, to disrupt adjacent Bruch's membrane first, followed by the edge of vein itselfo Signs of presumed rupture of Bruch's membrane, such as a vaporization bubble, and occasionally a small, self-limited intravitreal stream of hemorrhage, presumably from the adjacent retinal vein. Various laser parameters and wavelengths, including green> yellow, red and Nd:YAG were used. Powers of 800~900mw were used in most cases. In all cases the spot size was 50u, and the duration was 0.1 second. For 37 eyes, 86 anastomosis creations were completed