Comparison of the effect of ranibizumab and dexamethasone implant in diabetic macular edema with concurrent epiretinal membrane

Abstract

To compare the efficacy and safety of intravitreal ranibizumab (RZB) injections and intravitreal dexamethasone (DEX) implant in diabetic macular edema (DME) with concurrent epiretinal membrane (ERM). This was a retrospective, observational, comparative study. Medical records of DME patients with concurrent ERM were retrospectively reviewed. Seventeen eyes of 16 patients treated with 3 consecutive monthly RZB injections (RZB group) and 22 eyes of 18 patients treated with a DEX implant (DEX group) were included. The groups were compared at baseline, 1st, 2nd, 3rd and 4th months in terms of best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP). Eighteen of the 39 eyes (46.1%) were phakic at baseline, 9 (52.9%) of which were treated with RZB, whereas 9 (40.9%) were treated with DEX implant (P=0.528). Although CMT improved significantly in both the RZB and DEX groups (P<0.001); the trend was different (P=0.003). The mean change in CMT at 1month in the DEX group was greater (DEX: 188.2±142.7μm; RZB: 95.7±110.7μm; P=0.034); it was in favor of RZB group at the 3rd and 4th months (DEX: -52.7±86.9μm; RZB: 1.4±31.4μm; P=0.012. DEX: -63±67.3μm; RZB: -5.8±43.9μm; P=0.004, respectively). BCVA improved significantly in both groups (P<0.001). There was no statistical difference between the groups with regard to gain in BCVA or IOP change throughout the study period (P=0.572, P=0.064, respectively). Both RZB and DEX are effective in improving anatomical and visual outcomes in DME with concurrent ERM. The DEX group was associated with a prompt anatomic response, but with a gradual decrease from 3rd month.