To report a case of a Corynebacterium macginleyi -infected corneal ulcer of a patient who had been treated for conjunctivitis for more than 3 months.

A 72-year-old female was transferred from a private ophthalmic clinic for evaluation of herpetic keratitis with progressive corneal edema and infiltration in the left eye. She had a history of conjunctival hyperemia and eyeball pain in her left eye 3 months prior to her visit. She was treated with levofloxacin eye drops and acyclovir ointment (Herpesid®, Samil, Co., Ltd. Seoul, Korea). On slit lamp examination, 5.4 × 4.0 mm corneal epithelial defects and stromal infiltrations were observed in the upper to central cornea, and endothelial keratic precipitates were found. Gram positive bacteria were detected on Gram staining and Corynebacterium macginleyi was identified on bacterial cultures from the conjunctiva and cornea. She was treated with topical vancomycin eye drops. After 3 months of treatment, the corneal ulcer was completely resolved, leaving mild superficial opacity on the cornea.

While Corynebacterium macginleyi , normal flora of the conjunctiva, is considered a major causative agent for conjunctivitis and blepharitis, Corynebacterium macginleyi should also be considered a possible cause of slowly progressive keratitis in patients with chronic conjunctivitis.