Severe Staphylococcus lugdunensis keratitis

We report a severe case of Staphylococcus lugdunensis (S. lugdunensis) keratitis presenting as suppurative keratitis in a 77-year-old woman. The patient's chief complaint was eye pain and decreased visual acuity in her right eye. Suppurative keratitis with a severe corneal abscess was diagnosed by a slit-lamp ophthalmic examination. The causative organism was identified as S. lugdunensis by bacterial culture, using a corneal abrasion specimen. She was treated with an intravenous drip infusion of ceftazidime and instillation of gentamicin sulfate ophthalmic solution (six times daily) and ofloxacin ophthalmic ointment (once daily before bedtime) as empiric therapy. Her hospital course was complicated by a corneal perforation of her right eye. The antibiotic susceptibility for S. lugdunensis was sensitive, but with a slightly high MIC for antibiotics used in empiric therapy. The therapeutic drug was changed to levofloxacin ophthalmic solution. The corneal abscess left a scar after healing. Representative causative organisms of suppurative keratitis include Pseudomonas aeruginosa and Streptococcus pneumoniae, but care must be taken in cases involving rare causative organisms. Empiric therapy is necessary for rapidly progressing suppurative keratitis, but a detailed examination of the causative organism is important for therapeutic planning before empiric therapy.