Method: A retrospective study was designed to assess the functional and anatomic outcomes of switching therapy from R/B to afl ibercept in patients with persistent DME. The patients included in this study had persistent DME and received at least 3 previous anti-VEGF intravitreal injections in the last 6 months prior to baseline (pre-switch) examination. After applying 3 monthly loading doses of afl ibercept treatment, all the patients were evaluated every 4 weeks and put on an as-needed regimen in case of recurrence. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) were evaluated between pre-switch and the last examination after administering afl ibercept therapy.

Results: Fifty eyes of 33 patients were included in the present study. The mean follow-up time before afl ibercept and mean follow-up time after afl ibercept were 25.2±19.7 and 10.7 ± 4.5 months, respectively. The mean final BCVA (logMAR) increased to 0.69±0.44, which was statistically signifi cant compared to the baseline (0.81±0.37), (p= 0.007). The final BCVA showed a positive correlation to the baseline BCVA (p=0.001, r=0.720). The mean final CMT decreased to 373.9±146.1?m, which was statistically signifi cant compared to baseline (475±140), (p=0.00,1). . The final CMT showed a weak positive correlation to baseline CMT (p=0.003, r=0.430).

Conclusion: Conversion to afl ibercept in patients showing poor response to other anti-VEGF agents could result in signifi cant functional and anatomical improvements. Although the present study could not suggest an exact time to switch the therapy, clinicians should not wait for a signifi cant decrease in the BCVA. Keywords : Diabetic macular edema, aflibercept, switch anti-vascular endothelial agents, central macular thickness