The effect of simultaneous intravitreal Ranibizumab and intravitreal extended-release dexamethasone injection on patients with naïve versus refractory retinal vein occlusion macular edema: prospective, single-center, interventional, and open-label study

Abstract Background The efficacy of concurrent intravitreal Ranibizumab (IVR) and extended-release dexamethasone injections (Dex-I) in patients with naïve and refractory retinal vein occlusion macular edema (RVO-ME) was not well investigated previously. Methods This was a prospective, interventional, and open-label case series design. There were two groups: naïve and refractory patients (received ≥ 5 times of previous IVR within one year prior to enrollment) enrolled. Patients received IVR and Dex-I concurrently. IVR and Dex-I were given PRN. The mean change in best-corrected visual acuity (BCVA) was measured as main outcome. Results 63 patients (63 eyes) completed the entire follow-up (31 naïve and 32 refractory patients). At month 12, the change in BCVA was greater in the naïve group than in the refractory group (19.67 ± 11.7 (95%CI: 15.03,24.31) letters vs. 11.74 ± 11.18 (95%CI:7.32,16.16) letters, P = 0.014). There was no difference between the two groups of mean macular thickness reduction. (364.26 ± 215.29 (95%CI: 279.09,449.43)µm v.s. 410.19 ± 204.34 (95%CI: 329.35,491.02)µm, P = 0.43). The mean co-injection numbers were 2.52 ± 0.58 (95%CI:2.29,2.75) and 2.33 ± 0.55(95%CI:2.11,2.55) in both groups (P = 0.24). The retreatment interval was 115.81 ± 13.79 (95%CI: 110.36,121.27) days and 122.74 ± 14.06(95%CI: 119.93,133.56) days in both groups (P = 0.073). There was no significant difference in the incidence of glaucoma or the progression of cataracts between the two groups. Conclusion In both naïve and refractory RVO-ME patients, IVR combined with Dex-I was effective. The initial combination therapy for naïve patients demonstrated more efficient improvement in BCVA and may reduce total injection numbers. Trial registration: this study was registered with the identifier ChiCTR-INR-17011877 at https://www.chictr.org.cn/