New cause of infectious keratitis identified

US clinicians have described a case of infectious keratitis caused by the pathogen Nocardia sienata

close up of eye
Pixabay/Bruno Henrique

BMJ Case Reports authors have described a case of infectious keratitis in a 25-year-old man caused by Nocardia sienata.

The patient presented for treatment after experiencing two months of worsening pain in his left eye as well as an atypical corneal ring infiltrate.

The patient wore soft contact lenses but did not expose them to water. He worked in a warehouse that packaged marijuana products. He had no history of recent travel.

Visual acuity in the affected left eye was 6/12. Corneal cultures for bacteria, fungus and acanthamoeba all demonstrated no growth.

He was treated with eye drops containing a combination steroids and antibiotics for two weeks but his condition continued to worsen.

After three weeks, the organism which grew on atypical agar was identified as the Nocardia genus, prompting a switch in treatment to amikacin.

Four weeks after beginning treatment with amikacin, the infection completely resolved.

The clinicians highlighted that amikacin should be used as a first line therapy once a diagnosis of Nocardia keratitis is confirmed.

“Topical steroids should be cautiously used since they are associated with worse visual outcomes,” the authors shared.