Intravitreal dexamethasone implant in naive and previously treated patients with diabetic macular edema:a retrospective study

AIM:To assess the effect of the intravitreal dexamethasone implant(DEX)Ozurdex on the best corrected visual acuity(BCVA)and central retinal thickness(CRT)in patients with diabetic macular edema(DME).METHODS:Totally 43 eyes(24 naive and 19 previously treated)were included in the study.Retrospective and single-center study involved patients with a clinical diagnosed of DME,who received treatment with DEX implant and had a follow-up of at least 12 mo.Primary endpoints included changes in BCVA and CRT.RESULTS:At month 12,mean improvement in BCVA from baseline was 20.4±20.8 letters and 6.8±6.9 letters in naive and previously treated patients,respectively(P=0.0132).The naive patients achieved the BCVA improvement significantly faster(2.4±1.5 mo)than the previously treated ones(3.5±2.4 mo,P=0.0298;MannWhitney test).The proportion of eyes gaining≥15 letters was 54.2%and 21.1%in the non-previously treated and previously treated groups,respectively(P=0.0293).CRT was significantly reduced from 484.0±119.8 and 487.5±159.9μm to 272.0±39.2 and 233.5±65.7μm in the naive and previously treated patients,respectively;P<0.0001 each,respectively.The presence of subretinal fluid was significantly associated with the proportion of patients achieving a BCVA improvement≥5 letters[HR(95%CI),1.23(1.04 to 1.45),P=0.0145];≥10 letters[HR(95%CI),1.75(1.10 to 2.77),P=0.0182];and≥15 letters[HR(95%CI),2.04(1.03 to 4.02),P=0.0407].Naive patients received less DEX implants throughout the study than the previously treated ones(1.8±0.6 vs 2.3±0.6,P=0.0172,respectively).Totally 9 patients(20.9%)have developed ocular hypertension,which was successfully controlled with topical hypotensive drugs.Of the 23 phakic eyes at baseline,5 eyes(21.7%)either had new onset lens opacity or progression of an existing opacity during the study follow-up.Four of them(2 in the naive group and 2 in the previously treated one)required cataract surgery at months 4,6,6,and 6,respectively.CONCLUSION:The results obtained in this study may support the early use of DEX Ozurdex as first line therapy in naive patients.