Intravitreal Dexamethasone in Diabetic Macular Oedema: A Way of Enhancing the Response to Anti-VEGF in Non- or Poor Responders?

Background and purpose: The aim of this study was to describe the outcomes of a switch back to anti-vascular endothelial growth factor (VEGF) in diabetic macular oedema (DME) eyes treated temporarily with a dexamethasone implant (DEXi), after an initial poor response to anti-VEGF.

Methods: The study involved a case series.

Results: Twenty-three eyes of 17 patients were included. All were poorly responsive to anti-VEGF and switched to a DEXi after a mean of 12 anti-VEGF injections. The mean best-corrected visual acuity (BCVA) increased from 0.25 ± 0.19 (decimals) to 0.29 ± 0.20 after switching to the DEXi (p = 0.11). BCVA remained stable (0.31 ± 0.23; p = 0.11) after switching back to anti-VEGF, one month after the last injection. The mean central macular thickness (CMT) decreased significantly from 517.0 ± 128.5 μm to 343.4 ± 118.9 μm (p < 0.001) after switching to the DEXi. In eyes receiving ≥3 anti-VEGF injections during the switch back, the CMT 1 month after the last anti-VEGF injection was significantly decreased compared to the CMT before the switch to the DEXi (mean change of - 95.55 ± 89.82 μm, p = 0.005).

Conclusion: Switching back poorly responsive DME eyes to anti-VEGF after temporary DEXi therapy is associated with good anatomical and visual outcomes similar to those obtained with the DEXi, provided that at least 3 anti-VEGF injections are administered. The DEXi might restore retinal sensitivity to anti-VEGF.