To evaluate the efficacy of intravitreal ziv-aflibercept (IVZ) in patients with diabetic macular edema (DME) resistant to intravitreal bevacizumab (IVB).

This prospective non-masked study was conducted on patients with persistent DME after receiving at least three IVB injections. Patients were switched to IVZ and monitored over a course of 12 weeks. Changes in best corrected visual acuity (BCVA) as well as central macular thickness (CMT) and macular volume (MV) on OCT were compared.

A total of 59 eyes from 38 patients were included. Patients received an average of 7.3 bevacizumab injections before being switched to IVZ. Mean BCVA improved from 0.84 logMAR at baseline to 0.71 LogMAR (P=0.001) at one month after receiving the first IVZ and remained significant in every follow up visits. In subgroup analysis, this significance observed only in group with baseline VA<20/50. Mean CMT and MV decreased from 479 μm and 10.6 μm3 to 364 μm and 9.9 μm3 (P=0.004 and <0.0001) respectively, after the first IVZ injections and remained significant. Another subgroup analysis based on baseline CMT showed that patients with CMT > 375μm experienced a significant improvement in CMT and vision at all follow up visits. There was one case of culture positive endophthalmitis.

IVZ may be best reserved for patients with significant persistent DME after initial failure with bevacizumab with less likelihood for anatomic or functional improvement in those with mild persistent DME. IVZ may represent an attractive treatment in these patients, especially in lower income countries.