Making a point of care

One of the many changes to life since the pandemic has been an increased familiarity with point of care tests; tests that can easily be carried out directly on, or even by, the patient and yield results without the need for sending off to a lab. Most readers, for example, will be completing a lateral flow test this week (figure 1).

Point of care tests need to be able to identify some form of bio-marker, whether that be a protein, a pathogen or an antibody remnant, that is present in sufficient quantities in an accessible body fluid to be taken up by a swab and detected by a chemical response able to trigger a visible confirmation. Eye care practitioners have easy access to a body fluid that contains a wealth of potential biomarkers; the tears. Currently, almost 1,800 proteins are known to constitute the human tear proteome. Of these, a significant proportion are found to selectively decrease or increase in ocular surface diseases and thus are potential biomarkers.1