AIM: To evaluate the safety and efficacy of intravitreal bevacizumab injection in patients with macular edema(ME)induced by retinal vein occlusion(RVO).

METHODS: The records of patients treated with intravitreal injection of 1.75mg bevacizumab for ME induced by RVO were retrospectively reviewed. All patients were evaluated by complete ophthalmic examination, optical coherence tomography(OCT)and fundus fluorescein angiography(FFA), etc. Best corrected visual acuity(BCVA), intraocular pressure, the change of lens and vitreous, central foveal thickness(CFT)were observed at 1, 2, 3, 6mo after treatment and compared with before treatment. Repeated treatment with intravitreous bevacizumab occurred if there were signs of persistent or recurrent exudation. All the cases were followed up at least 6mo. An intravitreal injection of bevacizumab(1.75mg)was given at 6wk intervals.

RESULTS: Fifty patients(56 eyes)with the average of(57±18.56)years old were included. The mean baseline of BCVA, CFT were(logMAR0.82±0.63),(626.5±178.0)μm respectively. Although there was no significant decrease in mean CFT at 1wk after injection, the mean BCVA had significant improvement. Followed up at mean 10.26±5.87mo, BCVA, CFT showed significant improvements over baseline values. The statistics of CFT at 1, 2, 3mo after injection were significant differences compared with before injection in each of the three groups. CFT at 1, 3, 12mo after injection were(365.11±23.212)μm,(333.42±35.526)μm,(267.6±116.8)μm, which had a significant difference(P<0.001), namely macular retinal thickness was thinner obviously that before treatment, ME was improved obviously. CFT was no significant difference at each time point after injection in the group of BRVO-ME and CRVO-ME(P>0.05). OCT image showed that after injection macular retinal thickness was becoming thinner. FFA showed that after injection macular fluorescein leakage decreased. BCVA was improved by at least two lines in 48 eyes(86%),remained stable in 8 eyes(14%)at the last visit. A total of 112 injections were performed and the average number of injections was 1.96 in the group. About 50% of reinjections gained at least two lines of vision improvement at 1wk following the retreatment. There was no serious complications during the treatment.

CONCLUSION: Intravitreal injection of bevacizumab can improve visual acuity(VA)of RVO(CRVO and BRVO)in patients with ME, relieve ME, reduce the leakage of CNV, and repeated treatment is better. But a prolonged treatment effect needs further observation. There are no serious ocular and systemic complications occurred in our study.