Analysis of anatomical biomarkers in subtypes of diabetic macular edema refractory to anti-vascular endothelial growth factor treated with dexamethasone implant.

Abstract

To analyze functional and anatomical outcomes in subtypes of diabetic macular edema treated with a single dexamethasone implant and to assess the usefulness of a pro-re-nata treatment among subtypes. Retrospective study in morphologic patterns of diabetic macular edema (diffuse retinal thickening n = 15; cystoid macular edema n = 38, and serous retinal detachment n = 17) recalcitrant to anti-vascular endothelial growth factor, treated with dexamethasone implant. Examinations included timing to recidive of diabetic macular edema, best-corrected visual acuity, and central subfield macular thickness at 2, 4, and 6 months. In previously treated patients with a mean of 6.64 ± 3.69 anti-vascular endothelial growth factor injections, the best-corrected visual acuity improved from 61.64 ± 13.71 to 65.71 ± 14.65 as per the Early Treatment Diabetic Retinopathy Study protocol (p = 0.009) and central subfield macular thickness change from 447.46 ± 110.82 to 354.39 ± 80.46 µm (p < 0.005). The best-corrected visual acuity improvement was better in the diffuse retinal thickening group (68.67 ± 13.81 vs 65.26 ± 14.04 in cystoid macular edema and vs 64.12 ± 17.06 in serous retinal detachment), whereas higher central subfield macular thickness thinning was observed in serous retinal detachment group (368.47 ± 29.96 to 310.27 ± 67.47 in diffuse retinal thickening, vs 445.92 ± 105.06 to 364.39 ± 80.28 and 520.59 ± 122.96 to 370.94 ± 81.73 in cystoid macular edema and serous retinal detachment, respectively). Cystoid macular edema group was the group with more recurrences after 6 months (86.8% vs 66.7% in diffuse retinal thickening and 70.6% in serous retinal detachment). Dexamethasone implant is effective for all persistent diabetic macular edema subtypes with sustained functional and morphologic gains in the first 6 months.