A point-of-care diagnostics – similar to an at-home COVID-19 test kit – could detect microbial keratitis (MK) caused by Aspergillus fungus with good accuracy, according to a prospective study.
An Aspergillus-specific lateral-flow device is already approved by the United States Food and Drug Administration (FDA) for pulmonary aspergillosis testing. It was able to detect MK with high sensitivity for both corneal scrape (0.89, 95% CI 0.74–0.95) and swab samples (0.94, 95% CI, 0.73–1.00).
Overall accuracy was 0.94 (95% CI 0.90-0.97) and 0.88 (95% CI 0.73-0.96), respectively, according to the study, published in JAMA Ophthalmology.1
There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes
MK is a common cause of unilateral visual impairment, blindness, and eye loss in low-income and middle-income countries, the study authors said.
“There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes,” they wrote.
The diagnostic study was conducted between May 2022 and January 2023 at an Indian corneal clinic. All study participants were recruited at their first presentation to the clinic. Patients aged 15 years or older met the eligibility criteria if they had a corneal ulcer that was suggestive of a bacterial or fungal infection, and were about to undergo diagnostic scrape and culture.
Microbes causing the MK are bacteria in half of cases and fungi like Aspergillus in the other half, but clinicians usually can’t distinguish without testing, which can take days.
“This finding is of particular importance because swabs could be used to collect corneal samples from patients with suspected microbial keratitis in settings where the routine method of specimen collection by scraping is not possible, such as primary care,” investigators wrote.
- Gunasekaran, R., Mills, B., et al., Rapid Point-of-Care Identification of Aspergillus Species in Microbial Keratitis. JAMA Ophthalmol. 2023 Sep 28:e234214. doi: 1001/jamaophthalmol.2023.4214. Epub ahead of print. PMID: 37768674; PMCID: PMC10540059.
