Influence of prior treatment protocol on intravitreal dexamethasone implant behavior in patients with diabetic macular edema in real-world practice.

Background And Objective: Intravitreal dexamethasone implant (DEXI) has been placed as an effective option to treat diabetic macular edema (DME). However, there is no consensus on the best time to introduce it. We conducted a study to evaluate anatomical and functional behavior after the first DEXI according to previous treatment.

Research Design And Methods: This retrospective, real-world study between 2013 and 2020 investigated changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT at months 2 and 6 after the first DEXI in DME. Patients were divided into naive, early switch (≤3 anti-VEGF injections), or late switch (>3 anti-VEGF injections) groups.

Results: Among 112 consecutive eyes, mean BCVA and CMT improved significantly in all groups at month 2, with no difference between them. However, this improvement was not maintained at 6 months. The Naíve group presented better BCVA all over the study period. The previously treated groups, which started with worse initial visual acuity, showed more visual gain without reaching the BCVA of the naive group. CMT performance was similar between groups.

Conclusions: There was similar anatomical and functional behavior in all groups. Poorer visual acuity at baseline was associated with worse functional outcome despite good anatomic response.