Reusable contact lenses cause more inflammation

The joint project between researchers from the State University of New York and the University of New South Wales measured higher tear cytokine concentration and conjunctival cell metaplasia in reusable contact lens wearers, which indicated higher ocular inflammatory responses.{{quote-A:R-W:450-Q: The high inflammatory responses are a likely explanation for the common complaints of discomfort with prolonged use }}The researchers applied ocular surface staining using flourescein and lissamine green to analyse for tear cytokine concentrations, while two conjunctival impression cytology samples were taken from lens-covered and uncovered regions to evaluate for goblet cell density and conjunctival metaplasia.The study involved 36 regular contact lens wearers – 24 using reusable lenses and 14 using disposables. The participants were asked to wear lenses for one hour, after which basal tears were collected from the lower tporal tear meniscus of both eyes.Reusable contact lens wearers had higher tear cytokine concentrations, conjunctival cell metaplasia, and conjunctival staining compared to disposable lens wearers. According to the researchers, the high inflammatory responses are a likely explanation for the common complaints of discomfort with prolonged use.The authors also suggested that contact lens care solutions, particularly multipurpose solutions, contribute to inflammation.