Comparison of the efficacy of intravitreal Anti-VEGF versus intravitreal dexamethasone implant in treatment resistant diabetic Macular Edema

PURPOSE: Comparison of the efficacy of monthly anti-VEGF versus dexamethasone (DEX) implant in patients with diabetic macular edema (DME) whose macular edema persists despite three doses of anti-VEGF therapy. MATERIALS AND METHODS: This retrospective study included 94 eyes of 94 patients with central macular thickness (CMT) > 300 μm despite previously receiving three doses of anti-VGEF (aflibercept or ranibizumab) injections between January 2014 and January 2019. The patients were divided into four groups. The first and second groups were the patients who received three more doses of initial anti-VGEF treatment after the initial anti-VGEF treatment. The third and fourth groups were patients switched to intravitreal dexamethasone implants. Patients were followed up every month for six months after the injection. The primary outcome measures were best-corrected visual acuity (BCVA), central macular thickness (CMT), and intraocular pressure (IOP) at six months. RESULTS: The mean age of the patients included in the study was 64.64 ± 7; there were 58 men (61.7%) and 36 women (38.3%). There was no statistically significant difference between the groups regarding age, stage of retinopathy, and lens status. When CMT, BCVA, and IOP were assessed among the four groups at the end of the sixth month, no statistical difference between the groups was found. There was no need for medical intervention despite the statistically significant increase in IOP at the end of the sixth month compared to the third month in the dexamethasone implanted groups. In contrast to the decrease in CMT, which was statistically significant in all four groups at the end of the sixth month compared to the third month, the increase in BCVA was not statistically significant in any of the four groups at the end of the sixth month. CONCLUSION: According to the results of our study, there is no superiority between continuing with existing anti-VEGF or switching to a dexamethasone implant after three doses of anti-VEGF.