We report a case of herpes simplex keratitis after Descemet membrane endothelial keratoplasty (DMEK).

A 67-year-old male underwent DMEK in his left eye due to pseudophakic bullous keratopathy. One week after DMEK, re-bubbling was performed due to partial detachment of Descemet's membrane at the corneal periphery. After re-bubbling, the cornea remained clear and the patient's visual acuity gradually improved. Two months after DMEK, the patient presented with mild discomfort and decreased visual acuity. The cornea showed an irregular, narrow dendrite with an epithelial defect and surrounding opacity. After confirming that Descemet's membrane was attached, the patient was started on oral valacyclovir for suspected herpes keratitis. Herpes simplex virus type 1 was eventually identified by polymerase chain reaction. The corneal lesion resolved after three weeks of antiviral treatment.

Similar to penetrating keratoplasty, DMEK can trigger outbreaks of herpes simplex keratitis. Herpes simplex keratitis should remain on the clinician's differential diagnosis for patients who present with a corneal epithelial irregularity and decreased visual acuity following DMEK.