Safety and long-term efficacy of repeated dexamethasone intravitreal implants for the treatment of cystoid macular edema secondary to retinal vein occlusion with or without a switch to anti-VEGF agents: a 3-year experience.

Abstract

To evaluate the safety and efficacy of repeated dexamethasone intravitreal implants (DEX implants) over 3years in eyes with macular edema (ME) secondary to branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO). We conducted a 3-year, retrospective, multicenter study that included adult patients with ME secondary to BRVO or CRVO treated with first-line DEX implants. Patients were divided into two different subgroups: patients who received DEX implant injections only (group 1) and those who received DEX implants first and then were switched to anti-VEGF agents (group 2). Primary endpoints were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from baseline to month 6 and month 36. Secondary endpoints included changes in both BCVA and CRT after each DEX implant and adverse events, particularly cataract extraction and elevated intraocular pressure (IOP). Sixty-six patients with a median [IQR (interquartile ratio)] age of 72 [65.0; 81.1] years were included (40.9% BRVO, 59.1% CRVO), who received a median of 5.0 [min, 1.0; max, 10.0] DEX implants over 3years. Median [IQR] time to retreatment was 4.8 [4.2; 6.0] months. The median [IQR] improvements in BCVA from baseline until months 6 and 36 were respectively + 10.0 [0; + 20.0] letters (P = 0.040) and + 10.0 [- 8.7; + 20.0] letters (P = 0.364) in the whole population. In group 1, the results were similar, whereas in group 2, BCVA significantly increased at M36 compared with baseline (P = 0.003). The median [IQR] CRT reductions from baseline to months 6 and 36 were respectively - 227.5 [- 337.0; - 52.7] μm and - 224.0 [- 405.0; - 83.8] μm (P < 0.001) in the whole population. Results were similar in both groups. The most common adverse events were cataract extraction (70.4%) and elevated IOP (54.5%). No other serious local complications were observed. Treatment was switched to anti-VEGF agents in 16 (24.2%) patients. DEX implants are an effective treatment for BRVO and CRVO-associated ME over 3years. It is a valid treatment even though complications remain frequent. However, functional efficacy seems to decrease with time and repeated injections.