A 32-year-old man had undergone small incision lenticule extraction (SMILE) that was complicated by intraoperative epithelial detachment in the right eye. Corneal epithelial erosion reoccurred at two and four months after surgery. At the third time of epithelial erosion, slit-lamp examination revealed dense white infiltrates throughout the corneal cap-stromal interface. The patient was initially managed with high-dose topical antibiotics. After the negative culture and Gram staining results from the interface washout, diffuse lamellar keratitis was confirmed and topical steroids were administered. The inflammation resolved, and corneal transparency was achieved after treatment. Timely diagnosis and appropriate treatment are highly critical for prognosis.