AIM:To evaluate the 12mo results of intravitreal bevacizumab injection on central macular thickness(CMT)and visual acuity in the treatment of macular edema(ME)secondary to branch retinal vein occlusion(BRVO).

METHODS:Thirty-two patients who underwent intravitreal bevacizumab(Altuzan^®)0.125mg/0.05mL injection for ME secondary to BRVO at least 12mo follow up period have been studied respectively. Patients with diagnosis of ME secondary to BRVO were applied an ophthalmic examination, CMT measurement, and fluorescein angiography, so patients whose CMT above 250μm were offered intravitreal bevacizumab treatment. Patients who had macular ischemia on fluorescein angiography, neovascularisation elsewhere secondary to other types of diseases, received any intraocular treatment before(such as laser treatment, intravitreal injection or eye surgery)have been out of trial. Data of logMAR best corrected visual acuity(BCVA)and CMT in control visits have been evaluated. For statistical analysis Student's paired t-test was used by Minitab15.0 software and a P-value <0.05 was considered as statistically significant.

RESULTS: Mean logMAR BCVA changes and mean CMT changes were statistically significant compared to pre-injection values at last visit(P<0.01). Mean BCVA increment was 0.477±0.235, mean CMT decline was 257.906±88.865 compared to pre-injection at last visit. Ten(31%)of the patients had a positive response with a single injection and no recurrence of ME for a mean of 12.6±0.66mo. Five(15.6%)patients received injection two times and 17(53%)patients more than 3 injections. Mean injection per eye was 2.18±0.91(1～4)respectively. Recurrence of ME was seen aproximately in 2.45±0.63mo at the first control, 2.58±0.66mo at the second control and 3.17±0.48mo at the third control respectively. Five(15.6%)of the patients needed multiple injections for reducing ME whereas visual acuity gain was not achieved as ME reduced in those patients.

CONCLUSION: Treatment of ME secondary to BRVO with intravitreal bevacizumab seems effective, fast, safe, and commonly performed treatment. In order to achieve this lasting effect, we have to strengthen this post treatment non-edematous status by lasers or long lasting agents. Retinal venous circulation and ME must be observed on fluorescein angiography rather than making frequent injections. Reinjections must be done according to the clinical status of ME and the prediction of visual acuity gain.