Early versus late switch: How long should we extend the anti-vascular endothelial growth factor therapy in unresponsive diabetic macular edema patients?

PURPOSE

To compare the results of early versus late switch to the dexamethasone intravitreal implant Ozurdex in patients with diabetic macular edema who had a poor response to vascular endothelial growth factor inhibitors.

METHODS

Retrospective and single-center study conducted, in a real setting, on consecutive diabetic macular edema patients who were switch to an intravitreal dexamethasone implant after a poor response to anti-vascular endothelial growth factor treatment. Study sample was divided into two groups: (1) early-switch group, included those eyes who received three anti-vascular endothelial growth factor injections before switch and (2) late-switch group, included those eyes that received six or more anti-vascular endothelial growth factor injections before switch. The primary end-point was the difference in mean change in best-corrected visual acuity and in central subfoveal thickness.

RESULTS

A total of 69 (31 early-switch group and 38 late-switch group) eyes were included. In the early-switch group, median (25-75 quartile range) best-corrected visual acuity significantly increase from 0.2 (0.2-0.5) at baseline to 0.4 (0.3 -0.7) at month 24 (p = 0.0043). Whereas, in the late-switch group, best-corrected visual acuity did not increase (p = 0.8602). Central subfoveal thickness was significantly reduced in both early- and late-switch groups, p = 0.0002 and 0.0038, respectively. The proportion of eyes obtaining a central subfoveal thickness reduction ⩾ 10% was significantly greater in the early-switch group than in the late-switch group (71.0% vs 47.4%, respectively, p = 0.0498). Three (9.7%) and 10 (26.3%) eyes have developed ocular hypertension during the study in the early- and late-switch groups, respectively, p = 0.0816.

CONCLUSION

Early switch to Ozurdex in patients who did not adequately respond to anti-vascular endothelial growth factor therapy provided better functional and anatomical outcomes.