Dexamethasone implant with fixed or individualized regimen in the treatment of diabetic macular edema: the UDBASA study

Purpose : Ozurdex was approved for the treatment of diabetic macular edema (DME) following the efficacy and safety results of the MEAD registration trial. During the first 6 months of the study, a steady decline in visual acuity gain was reported between 3 and 6 months.The aim of the UDBASA study is to evaluate whether a different treatment schedule, with monthly monitoring and PRN treatment might hold advantages as compared to the fixed 6-month regimen of the MEAD study. Methods : This exploratory study is designed as a comparative multicenter, interventional case series with a follow-up of 6 months. Patients with clinically significant DME were assigned to treatment at baseline either with a single Ozurdex implant during the entire 6-month follow-up (fixed group) or Ozurdex implant followed by re-treatment on an individualized basis (PRN group). Patients were scheduled for monthly evaluation based on assessment of best-corrected visual acuity (BCVA), optical coherence tomography (SD-OCT) and fundus biomicroscopy. The primary outcome was a change in BCVA (logMAR) between two treatment regimens. Secondary outcomes included reduction in central retinal thickness (CRT) and number of injections administered. Safety data were recorded. Results : Twenty eyes were enrolled to the PRN group and 22 were included in the fixed group. At 6 months mean BCVA improvement was 0.14 and 0.03 logMAR in the PRN and fixed group, respectively. The difference between two groups in BCVA change was 0.11 logMAR (n.s.) at the end of the study. At 6 months, CRT decreased on average by 91 and 50 µm in the as-needed and fixed arm, respectively. The difference between two groups in CRT reduction was statistically significant at month 4 and 5. In the PRN group, 40% of eyes did no require further treatment throughout the period of study and the mean number of injections was 1.6 in 6 months. Thirty percent of eyes in the PRN group and 14% in the fixed group showed an intraocular pressure elevation (IOP>21 mmHg) and required topical treatment. Cataract surgery was performed in 40% and 47% of phakic eyes in the PRN group and in the fixed group respectively. Conclusions : Compared to the fixed 6-month regimen, Ozurdex with monthly monitoring and PRN treatment is more effective in maintaining functional and anatomical benefits for the treatment of DME.