Effect of intravitreal aflibercept on recalcitrant diabetic macular edema

Despite anti-VEGF therapy, some patients develop chronic diabetic macular edema. The objective of this study was to evaluate anatomic and visual outcomes of switching patients with chronic DME from intravitreal bevacizumab or ranibizumab to intravitreal aflibercept injection. In this retrospective observational case series, 11 eyes with recalcitrant diabetic macular edema (DME) were evaluated 6 months prior to and 6 months following initial intravitreal aflibercept injection (IAI). Recalcitrant DME was defined as having a thickened retina (≥350 μm) on spectral domain optical coherence tomography (SD-OCT) with persistent cystic changes (less than a 15% reduction in central retinal thickness) over 6 months prior to intravitreal aflibercept switch despite aggressive treatment for DME during this time. One hundred and forty-seven patients in total were treated with IAI during this time, and of these, 31 patients were treated with IAI for DME. 18 eyes had less than 4 treatments within the 6 months prior to switch to IAI, 6 patients had a central retinal thickness (CRT) on SD-OCT of less than 350 μm at time of switch to IAI, and 2 patients had a greater than 15% decline in CRT on SD-OCT over the 6 months prior to switch to IAI. A total of 11 patients were included in the study. Over the 6 months prior to switch, the mean change in central retinal thickness was +18.6% and over the 6 months following switch to aflibercept the mean change in central retinal thickness was -27.1%. Switching to a regimen of at least 3 intravitreal aflibercept injections over 6 months resulted in some anatomic improvement and improvement or stabilization of Snellen visual acuity in all eligible patients. In patients with recalcitrant diabetic macular edema, switching to intravitreal aflibercept resulted in improved a 25% or more decrease in central retinal thickness in 81% (9/11) patients at 6-month follow-up. Sixty-three percent (7/11) had improvement in Snellen visual acuity after switching to intravitreal aflibercept injection, suggesting some reversibility of functional damage.