Materials and Methods: A total of 21 eyes of 21 patients who were switched to IVA theraphy due to recalcitrant DME to prior IVR treatment were studied retrospectively. The visual and anatomical parameters at baseline, post IVR treatment and 6 months following initial IVA injection were compared. The effect of DME type on the outcomes and the predictive factors were also evaluated by performing a multiple lineer regression model.

Results: The mean number of IVR injections was 6.1±1.4 (5-9) before switching. The mean number of IVA injections after switching was 3.3±0.5 (3-5). The mean central macular thickness (CMT) was 426.3±91.7 ?m at baseline and 417.6±80.8 ?m after IVR injections. After switching to IVA the mean CMT was decreased to 285.7±46.8 ?m (p<0.001). The best corrected visual acuity (BCVA) was 0.5±0.3 Logmar at baseline and 0.3±0.2 Logmar after IVR injections. After switching to IVA the mean BCVA was improved to 0.16±0.15 Logmar (p<0.001). The patients with diffuse retinal thickening responded better to IVA injections than the patients with other DME subtypes regarding to CMT (p=0.044). However, BCVA improvement was limited in those patients. The number of IVA injections was a good predictor for fi nal CMT and the DME subtype was a good predictor for BCVA.

Conclusion: In patients with refractory DME to prior IVR injections, switching to IVA resulted in anatomical and visual improvement. Keywords : Intravitreal ranibizumab, intravitreal afl ibercept, diabetic macular edema