Pseudophakic cystoid macular edema (CMO) known to appear in 0.1—2.35% of patients after phacoemulsification is one of the common causes of vision decrease during postoperative period. The authors analyzed a case of CMO development in a pseudophakic patient diagnosed 7 months after uncomplicated phacoemulsification. Optical coherence tomography (OCT) was suggested for patients with low vision and a sensation of shroud before the eye for early diagnosis of pathological process. Intravitreal injection of the 0.7 mg dexamethasone micro-implant performed soon after establishing the diagnosis was proved to be viable for postoperative CMO arrest in patients without previous treatment. One month after intravitreal implant injection, the visual acuity in the patient’s eye improved from 0.4 to 0.7, and retinal thickness in the macular area decreased from 705 to 255 μm. The result remained stable for 10 months. Intravitreal micro-implant appeared to have higher efficiency in contrast with traditional treatment methods (according to literature data), which was attributed to direct drug delivery to the area of pathological process. The use of 0.7 mg dexamethasone implant did not increase the intraocular pressure indicating its potential viability for patients with compensated glaucoma.