Intravitreal Injection of Conbercept Combined with Dexamethasone for Macular Edema Following Central Retinal Vein Occlusion

Background: To compare the efficacy of intravitreal injections of Conbercept combined with dexamethasone (DEX) for macular edema (ME) following central retinal vein occlusion (CRVO).

Methods: This was a prospective, single-masked, randomised, controlled clinical trial. Patients with ME following CRVO were randomised into groups to receive intravitreal injections of 0.5 mg Conbercept plus 0.2 mg DEX or 0.5 mg Conbercept alone on day 0 followed by repeat injections as indicated. The primary outcome measure was the change in best-corrected visual acuity (BCVA) from baseline to month 12. Secondary outcome measures included decrease in central retinal thickness (CRT), injection frequency and interval and percentage of patients who gained more than 15 ETDRS letters or achieved a CRT of < 250 μm at month 12.

Results: 33 males (51%) and 32 females (49%) were initially recruited with an average age of 56.64 ± 13.88 years. Patients in the Conbercept and Conbercept + DEX groups gained an average of 14.55 ± 19.19 and 14.88 ± 17.68 ETDRS letters, respectively, at months 12 (t = 4.221, P = 0.000; and t = 4.834, P = 0.000) with no significant difference between the two groups (t = 0.071, P = 0.943). In the Conbercept group, the mean reduction in CRT from baseline to month 12 was 435.26 ± 293.37 μm (t = 8.261, P = 0.000) compared to 431.36 ± 294.55 (t = 8.413, P = 0.000) in the Conbercept + DEX group. There was no significant difference between the two groups (t = 0.053, P = 0.958). The Conbercept + DEX group received fewer intravitreal injections. No major complications occurred.

Conclusion: Conbercept, alone or with DEX, can improve BCVA and reduce CRT in ME following CRVO without serious adverse events. The treatment interval was longer in the Conbercept + DEX group.

Trial registration: The study was registered with the Chinese Clinical Trial Registry at 5 July 2017. (http://www.chictr.org.cn, 05/07/2017 Registration Number: ChiCTR-INR-17011877).