Posters

5 year microbiology results for microbial keratitis from Torbay and South Devon NHS Foundation Trust

Poster Details

First Author: S.Levy UK

Co Author(s):    J. Court                    

Abstract Details

Purpose:

Microbial keratitis is a common ophthalmic presentation with the potential for blinding disease if not treated promptly with antimicrobials. Current topical empirical treatment regimens vary throughout the world. To better treat patients with microbial keratitis we were keen to identify the common organisms grown from corneal scrapes taken in the department, as well as the sensitivities of the organisms. We also analysed contact lens growth, if sent, in these patients to see if the results provided additional information which was of benefit when making the clinical diagnosis and in treating the patient.

Setting:

Torbay and South Devon NHS Foundation Trust Ophthalmology Department serves a resident population of approximately 286,000 people in the South West of the UK. Between 2018 and 2019 the department had 78,370 ophthalmology outpatient attendances.

Methods:

A retrospective review of patients who had corneal scrapes sent to the Torbay and South Devon NHS Foundation Trust Microbiology department between 2015 and 2019 was conducted. The corneal scrape gram stain results, culture growth and sensitivities for the organisms were then analysed. Of the microbial keratitis patients any patients who had contact lenses sent to the microbiology department during the 5 year period were analysed. Medisoft electronic records and electronic clinic letters were reviewed for complex cases and for all contact lens cases, to assess if the lens results altered management and treatment.

Results:

243 corneal scrapes were sent to microbiology over the 5 year period with considerably less scrapes being performed in 2019 (20) compared to 2015 (69). 34 of these patients had contact lenses sent. 51.9% of the scape samples showed no growth. The most common gram positive organisms were; coagulase negative staphylococcus and bacillus species and gram negative organisms were; pseudomonas aeruginosa and serratia species. 4 of 185 organisms were resistant to both cefuroxime and ofloxacin. Five organisms, which were grown on 16 occasions, showed resistance to ofloxacin. Fungal growth was found on 31% of the contact lenses and multiple bacterial organisms from each lens.

Conclusions:

Resistance to commonly used topical empirical antibiotics, ofloxacin and cefuroxime, is low and does not appear to be increasing. There is a trend in sending less corneal scrapes which we hypothesise is due to patients presenting earlier following better awareness of the risks associated with contact lens use. Contact lenses frequently grew multiple organisms with a high fungal growth rate. Contact lens microbiology results did not change clinical management. With low resistance to ofloxacin there is evidence in this department that monotherapy with preservative free levofloxacin, which has better pseudomonas cover, may be appropriate and result in less corneal toxicity.

Financial Disclosure:

None