[Clinical study of laser-induced chorioretinal venous anastomosis].

OBJECTIVE: To test the effectiveness and safety of laser-induced chorioretinal venous anastomosis in the treatment of nonischemic central retinal vein occlusion (CRVO), and also the effectiveness of the preventative measures for complications associated with the treatment.

METHODS: Laser-induced chorioretinal venous anastomosis was performed on 34 cases, 35 eyes with nonischemic CRVO. During the treatment, preventative measures for complications were taken as follows: (1) Patients with total retinal papillary nonperfusion area of less than 5 DA were selected to receive the treatment. (2) Treatment sites must be at least 3 PD away from the optic disc and 4 PD away from the macula. (3) At most 2 argon laser shots were attempted over each treatment site, to avoid severe laser damage. (4) Scattered argon laser photocoagulation was done over the drainage area of the vein distal to the treatment site, in order to prevent neovascular complications in case distal vein occlusion occur.

RESULTS: During the 3 approximately 12 months (average 6 months) follow-up, successful anastomosis formed in 28 eyes out of 35 eyes (80%) with a mean of 2.4 attempts to create an anastomosis in each eye. With successful anastomosis, retinal hemorrhage started to be absorbed gradually 2 weeks after the treatment, and almost entirely absorbed 1 approximately 2 months later. Retinal edema also alleviated. Visual acuity improved in 20 out of 28 eyes (71%), and remained unchanged in the rest of the patients with successful anastomosis. In comparison with the natural course of the disease, our treatment has improved both the visual prognosis and the retinal damage caused by the disease. No serious complications occurred in these patients with successful anastomosis. Anastomosis failed to form in 7 cases (7 eyes), among which, 2 eyes developed serious neovascular complications.

CONCLUSIONS: CRVA treatment is effective in the treatment of non-ischaemic CRVO. With proper preventative measures for complications associated with the treatment, the safety of the treatment can be increased prominently, but serious neovascular complications was not entirely prevented.