EFFICACY OF COMBINED DEXAMETHASONE IMPLANT AND NAVIGATED SUBTHRESHOLD MICROPULSE YELLOW LASER IN DIABETIC MACULAR EDEMA.

Abstract

To compare functional and anatomical outcomes of combining intravitreal dexamethasone implant (DEX-I) (Ozurdex) with navigated subthreshold yellow (577 nm) micropulse laser (subthreshold micropulse laser treatment [SMLT]) versus dexamethasone monotherapy in diabetic macular edema. In this prospective randomized study, 80 eyes with center-involving diabetic macular edema were allocated to two groups: 40 eyes received DEX-I followed 4 weeks later by navigated SMLT (DEX-I + SMLT), and 40 eyes received DEX-I alone (DEX-I). Best-corrected visual acuity (Early Treatment Diabetic Retinopathy Study - ETDRS letters), central subfield thickness, and ETDRS subfield thicknesses were measured at baseline and at 2, 4, 6, 9, and 12 months. Reinjection-free survival was analyzed over 12 months. At 6 months, mean best-corrected visual acuity improvement was greater in the DEX-I + SMLT group than in the DEX-I monotherapy group (6.2 ± 5.1 vs. 4.1 ± 6.4 letters; P = 0.03), and this difference persisted at 12 months (5.8 ± 6.5 vs. 3.6 ± 6.8 letters; P = 0.05). Mean central subfield thickness was lower in the DEX-I + SMLT group at 6 months (295 ± 46 vs. 321 ± 58 µ m; P = 0.02) and remained lower at 12 months (315 ± 60 vs. 342 ± 70 µ m; P = 0.05). Median retreatment-free survival was longer in the combination group (11.2 vs. 8.3 months). Within the 12-month follow-up period, sequential navigated SMLT performed 4 weeks after dexamethasone implantation was associated with improvements in visual and anatomical outcomes and with a longer retreatment-free interval compared with dexamethasone monotherapy, without additional safety concerns.