AIM: To compare the efficacy and safety of dexamethasone intravitreal implant combined with anti-VEGF drug and anti-VEGF drug monotherapy in the treatment of macular edema secondary to retinal vein occlusion(RVO-ME).

METHODS: A total of 133 patients(133 eyes)diagnosed with central retinal vein occlusion(CRVO)or branch vein occlusion(BRVO)secondary to macular edema in the Xiamen Eye Center of Xiamen University from June 2019 to December 2020, including 48 patients with CRVO-ME and 85 patients with BRVO-ME were analyzed. All patients were randomly assigned to monotherapy or combination therapy. The monotherapy group(66 eyes)received a monthly injection of conbercept for consecutive 3mo, followed by monthly follow-up visits; The combination therapy group(67 eyes)received once intravitreal dexamethasone implantation, and conbercept was injected once 1wk later, followed by monthly follow-up visits.All patients in the two treatment groups were evaluated at baseline and every subsequent visit until 6mo after treatment with the best corrected visual acuity(BCVA), macular central retinal thickness(CRT), and injection times of conbercept and ocular and systemic adverse events associated with intravitreal injection therapy were recorded.

RESULTS: At 1, 2, 3 and 6mo after treatment, the BCVA and CRT in both groups were significantly improved than before.But there was no significant difference in the improvement of BCVA and CRT(P >0.05). From the initial intravitreal injection to 6mo, the injection times of the monotherapy group and the combination therapy group were 3.56±0.12 and 2.96±0.17 times, respectively. The injection times of the combination therapy group were significantly lower than those of the monotherapy group(P=0.004). Both the incidences of intraocular hypertension and cataract in the combination therapy group were higher than those in the anti-VEGF monotherapy group.

CONCLUSION: dexamethasone intravitreal implant combined with anti-VEGF drugs is an effective method for the treatment of RVO-ME, with significantly improved visual acuity and significantly lower CRT; The combined treatment regimen can reduce the times of injections and achieve similar results to anti-VEGF drug monotherapy. However, monitoring of intraocular pressure and cataract progression is required.