To report a successful case of corneal ulcer caused by multidrug-resistant Pseudomonas aeruginosa using topical colistin in an immobilized patient who was hospitalized for a long period.

An immobilized 58-year-old female who was admitted for a long stay due to cerebral aneurysm hemorrhage presented with left ocular discharge and hyperemia, and was referred to our clinic. The patient was treated at a local clinic with topical antibiotics, but showed no improvement. At initial visit, she had difficulty communicating with the medical team and taking ophthalmic examination, and she had severe chemosis and corneal infiltration, corneal opacity, and hypopyon on her left eye with a portable slit lamp. Gram staining, bacterial and fungal cultures, and an antibiotic sensitivity test were performed from a corneal scrape. The cultures revealed growth of Pseudomonas aeruginosa , which is resistant to all antibiotics except colistin. As soon as we were aware of the results of the antibiotic sensitivity test, she was treated with topical colistin 0.19% every 1 hour on her left eye, starting immediately. After 28 days of treatment, the infection was resolved except for the remaining corneal opacity. She had a persisted stable corneal lesion at 1-year-follow up after colistin treatment, which indicated no recurrence.

Due to gait disturbance, the patient almost missed appropriate ophthalmic examination or treatment. However, as we started immediate topical colistin treatment, we report a successful therapy of corneal ulcer induced by multidrug-resistant Pseudomonas aeruginosa without severe complications, such as perforation.