Prognostic Factors for Functional and Anatomic Outcomes in Patients with Diabetic Macular Edema Treated with Dexamethasone Implant

PURPOSE: To investigate the prognostic factors of visual and anatomic outcomes in patients with diabetic macular edema (DME) treated with intravitreal injection of dexamethasone implant. METHODS: We retrospectively studied 32 eyes of 31 patients with DME for best-corrected visual acuity (BCVA), central macular thickness, and height and width of both intraretinal fluid (IRF) and subretinal fluid. Logistic regression analysis was used to examine correlations between the baseline characteristics and outcomes at 3 and 6 months. RESULTS: Baseline predictor of BCVA ≥20 / 40 at month 3 was short height of baseline IRF (p = 0.02), while good baseline BCVA was a predictor for month 6 (p = 0.01). Predictors of improvement in logarithm of minimum angle of resolution BCVA 0.2 at month 3 were the absence of baseline IRF and poor baseline BCVA (p = 0.02 and p = 0.009, respectively), while poor baseline BCVA was the sole predictor at month 6 (p = 0.01). Predictor of central macular thickness ≤300 µm at month 3 was younger age (p = 0.03), while the absence of IRF was the predictor for BCVA improvement at month 6 (p = 0.02). BCVA ≤20 / 100 at month 3 was predicted by poor baseline BCVA (p = 0.01), and increased width of total IRF was the predictor at month 6 (p = 0.02). Predictor of loss of logarithm of minimum angle of resolution BCVA 0.2 at month 6 was increased width of total IRF at baseline (p = 0.04). Additional injection within 6 months was negatively associated with the presence of baseline DME (p = 0.03). CONCLUSIONS: The visual and anatomical outcome of DME treatment with dexamethasone implant can be predicted by baseline visual acuity and IRF morphology.