Purpose: To investigate the associations between early anatomical responses and intraocular pressure (IOP) changes in macular edema (ME) due to retinal vascular diseases treated with an intravitreal dexamethasone (DEX) implant. Methods: A retrospective review was conducted involving ME patients who underwent intravitreal DEX implantation. The eyes were divided into increased IOP (IIOP) or non-IIOP (nIIOP) groups according to the presence or absence of significant IOP elevation. Significant IOP elevation was defined by both the absolute value of IOP elevation (5 mmHg or higher) and an elevation percentage of the baseline IOP (an increase equal to 30% of the pre-injection IOP or higher). We analyzed the difference in central subfield thickness (CST) change according to the IOP elevation after DEX implantation. Relationships between IOP change and CST reduction after intravitreal DEX implantation were analyzed by Pearson correlation coefficients. Results: A total of 49 eyes, 29 with diabetic ME and 20 with ME due to retinal vein occlusion (RVO), were included in this study. Of the 49 eyes, 18 eyes (36.7%) were classified as IIOP group and 31 (63.3%) as nIIOP group. Significant differences in mean CST reductions over baseline one week after DEX implantation were observed between the groups. The degree of CST reduction from baseline to 1 week was significantly correlated with the degree of IOP change from baseline at 1 week and 1 month after intravitreal DEX implantation. Conclusions: In patients with ME due to retinal vascular diseases, we noted an early anatomical response significantly correlated with IOP change after intravitreal DEX implantation. Therefore, patients with favorable early anatomical responses to DEX implantation should be carefully monitored for IOP elevation.