Antimicrobial resistance (AMR) has been described as a global health threat by The World Health Organisation. Resistant organisms can lead to ocular infection that irreversibly damages the eye’s structures, resulting in vision loss and even blindness. Prompt use of appropriate antimicrobials can preserve vision.
The central cornea has a white opacity known as ‘infiltrate’ with an epithelial defect and conjunctival injection
A study – the Bacterial Ocular Surveillance System study (BOSS) – lead by Sydney specialists, has found an alternative to the Australian empiric antibiotics currently recommended for microbial keratitis by the Therapeutic Guidelines Australia (www.tg.org.au).
The Bacterial Ocular Surveillance System study (BOSS) promotes rational antimicrobial use for ocular infection potentially saving sight. Previously known as Keratitis Antimicrobial Resistance Surveillance Program (KARSP), BOSS examined 374 bacteria isolated from cases of microbial keratitis at Sydney Eye Hospital from 1 January 2017 to 31 December 2018.
Prof Stephanie Watson from the Corneal Research Group at the University of Sydney Save Sight Institute and Prof Monica Lahra from NSW Health Pathology led the BOSS. AMR profiles were analysed in the context of the current Australian empiric regimens for topical therapy: ciprofloxacin/ofloxacin monotherapy versus combination therapy of cefalotin/cephazolin plus gentamicin. At the Sydney Eye Hospital, combinations of chloramphenicol plus gentamicin; and chloramphenicol plus ciprofloxacin are alternatively used, so they were also analysed.
The study reported no significant difference between antimicrobial cover provided either with ciprofloxacin/ofloxacin vs cefalotin/cephazolin plus gentamicin. However, a treatment with chloramphenicol plus ciprofloxacin/ofloxacin or gentamicin, had significant improved cover. To access the report, visit doi.org/10.33321/cdi.2020.44.86.
Dr Maria Cabrera-Aguas, who compiled the report commented, “BOSS has allowed us to choose the best antimicrobials for microbial keratitis. I am looking forward to reporting BOSS data for 2019-2020 in 2021. We will need to watch for any further increases in resistance to cefalotin and whether fluoroquinolone resistance emerges as has happened in the USA and India”.
To prevent sight loss from microbial keratitis it is also important to understand why infection occurs. The BOSS review of 1,052 cases of microbial keratitis cases from the Sydney Eye Hospital from 2012 to 2016 was published in Graefe’s Archive for Clinical and Experimental Ophthalmology Journal in April 2020. Nearly nine out of 10 people had at least one predisposing factor; with contact lens wear the most common, found in two-thirds of the cases. To access the article, visit doi.org/10.1007/s00417-020-04681-0
For more information on the study contact Prof Stephanie Watson at [email protected].
