Shall we stay, or shall we switch? Continued anti-VEGF therapy versus early switch to dexamethasone implant in refractory diabetic macular edema

Aims: To compare functional and anatomical outcomes of continued anti-vascular endothelial growth factor (VEGF) therapy versus dexamethasone (DEX) implant in eyes with refractory diabetic macular edema (DME) after three initial anti-VEGF injections in a real-world setting. Methods: To be included in this retrospective multicenter, case–control study, eyes were required: (1) to present with early refractory DME, as defined by visual acuity (VA) gain ≤ 5 letters or reduction in central subfield thickness (CST) ≤ 20%, after a loading phase of anti-VEGF therapy (three monthly injections) and (2) to treat further with (a) anti-VEGF therapy or (b) DEX implant. Main outcome measures were change in visual acuity (VA) and central subfield thickness (CST) at 12 months. Due to imbalanced baseline characteristics, a matched anti-VEGF group was formed by only keeping eyes with similar baseline characteristics as those in the DEX group. Results: A total of 110 eyes from 105 patients were included (anti-VEGF group: 72 eyes, DEX group: 38 eyes). Mean change in VA at 12 months was − 0.4 ± 10.8 letters (anti-VEGF group), and + 6.1 ± 10.6 letters (DEX group) (P = 0.004). Over the same period, mean change in CST was + 18.3 ± 145.9 µm (anti-VEGF group) and − 92.8 ± 173.6 µm (DEX group) (P < 0.001). Eyes in the DEX group were more likely to gain ≥ 10 letters (OR 3.71, 95% CI 1.19–11.61, P = 0.024) at month 12. Conclusions: In a real-world setting, eyes with DME considered refractory to anti-VEGF therapy after three monthly injections which were switched to DEX implant and had better visual and anatomical outcomes at 12 months than those that continued treatment with anti-VEGF therapy.