To report a case of acute endophthalmitis after a dexamethasone (Ozurdex®) intravitreal implant for macular edema (ME) secondary to branch retinal vein occlusion (BRVO).

A 63-year-old male patient presented with decreased vision in the right eye due to ME secondary to BRVO. The patient was treated with an intravitreal bevacizumab injection, but ME did not improve. Two months after the injection, dexamethasone (Ozurdex®) intravitreal implantation was performed. Four days after the implantation, the patient visited our clinic complaining of severe visual disturbance. Slight conjunctival injection was observed and inflammatory cells and hypopyon were found in the anterior chamber. Fundus was not visible due to vitreous opacity. The patient was presumed to have acute endophthalmitis. Vitrectomy, intravitreal antibiotics injection, dexamethasone implant removal and phacoemulsification were performed. After treatment, the patient's fundus markedly improved, the inflammatory response was controlled and coagulase negative staphylococcus was detected from vitreous culture.

In cases of intravitreal dexamethasone implant associated with acute endophthalmitis, careful examination for diagnosis of endophthalmitis is recommended because the patient may not present with severe ocular pain and injection due to anti-inflammatory effect of corticosteroid.