Posters

To report a case of bandage contact lens wear related infectious keratitis caused by Rhizobium Radiobacter

Poster Details

First Author: V.Ho UK

Co Author(s):    S. Maqsood   S. Curtis   D. Lake              

Abstract Details

Purpose:

Rhizobium radiobacter is part of the Rhizobium genus which contains of four other species (R. rhizogenes, R. ribu, R. undicola and R. vitis). R. radiobacter is the only known opportunistic human pathogen. They are aerobic, non-spore-forming gram-negative bacilli, first reported in 1980, affecting a patient with prosthetic aortic valve endocarditis. Catheter related infection, bacteremia and pneumonia are some of the conditions caused by the pathogen. In eye, R. radiobacter has been isolated in cases of endophthalmitis post-cataract surgery or intravitreal injections and microbial keratitis.

Setting:

A case report in a corneal unit of a tertiary centre.

Methods:

A 84 year old man with a history of left retinal vein occlusion, secondary glaucoma, with light perception, developed band keratopathy requiring EDTA chelation and superficial keratectomy. The procedure gave patient short-term relief however band keratopathy recurred, monthly bandage contact lens was given instead for comfort as patient refused further surgery. Patient presented with small irritation in his left eye 18 months later. On slitlamp examination, he was found to have a moderately injected conjunctiva, a large central epithelial defect along the interpalpebral area, surrounded by multiple small foci of subepithelial and anterior stromal infiltrates on his opaque cornea.

Results:

Patient was started on intensive topical moxifloxacin whilst waiting for microbiology result. After 2 days of treatment, patient complained of increasing pain and intolerant to moxifloxacin with little resolution of signs hence treatment was changed to hourly cefuroxime and gentamicin. Corneal scraping result showed Rhizobium radiobacter, which is a gram-negative plant pathogen, sensitive to quinolones and cefuroxime. Treatment was changed to cefuroxime and levofloxacin (preservative free) according to the sensitivity of culture results and to reduce ocular surface toxicity. Patients’ symptoms improved significantly within a week with less pain, reduced density of infiltrates and stable vision.

Conclusions:

In the 5 reported cases of keratitis, all occurred in younger patients with a healthy ocular surface who were either contact lens wearer or had ocular trauma. Culture sensitivity to the isolated R. Radiobacter was sensitive to quinolone, and had good response to the treatment within a month with variable visual outcomes. The differences between these cases and our reported case was that our patient was in a older age group with a poor ocular surface who developed keratitis secondary to chronic contact lens wear and possible of direct exposure to soil, with quick and good response to topical treatment.

Financial Disclosure:

None