To compare the efficacy of intravitreal dexamethasone implants according to previous response to bevacizumab treatment in patients with diabetic macular edema (DME). Methods

Forty-nine eyes of 49 patients who received intravitreal dexamethasone implants for DME were reviewed retrospectively. Of these patients, 13 were treatment-naïve and 36 had previously received intravitreal injections of bevacizumab. Of the 36 previously treated patients, 24 comprised a refractory group showing no response to previous injections, and 12 comprised a responder group showing a response to previous treatments. The best-corrected visual acuity, central macular thickness (CMT), and retreatment percentages were assessed monthly for 6 months. Results

After the intravitreal dexamethasone implants, visual acuity improved significantly over 6 months in the treatment-naïve group, while in the responder group, a significant improvement in visual acuity was seen at the 2-month follow-up. In the refractory group, there was no significant improvement in visual acuity during the follow-up period. The CMT showed a significant decrease in all three groups, and there was no significant difference in the CMT among the three groups at any time point. Five patients in the treatment-naive group (38.5%), 19 patients in the refractory group (79.2%), and nine patients in the responder group (75.0%) needed retreatment for recurrent macular edema, and there was a significant difference among the three groups in the rate of recurrence ( p = 0.034). Conclusions

In DME patients, intravitreal dexamethasone implants were associated with a significant anatomical improvement irrespective of previous bevacizumab treatment response. However, the treatment-naïve and responder groups showed improvements in visual acuity, whereas the refractory group showed limited improvement.