Reusable Contacts Increase Risks for Acanthamoeba Keratitis

FRIDAY, Sept. 30, 2022 (HealthDay News) -- The risk for Acanthamoeba keratitis (AK) is tripled in daily wear (DW) reusable contact lens users versus daily disposable (DD) contact lens users, according to a study published online Aug. 8 in Ophthalmology.

Nicole Carnt, Ph.D., from University of New South Wales in Sydney, and colleagues assessed risk factors for the development of AK for DD contact lens users compared to DW reusable lens users. The analysis included 83 AK cases and 122 controls.

The researchers found that when adjusting for potential confounders, the odds of AK were higher for DW reusable soft lenses (odds ratio [OR], 3.84) and rigid lenses (OR, 4.56) than for DD lenses. Among DD users, AK was associated with less frequent professional follow-up visits (OR, 10.12), showering in lenses (OR, 3.29), lens reuse (OR, 5.41), and overnight wear (OR, 3.93). The population attributable risk percentage estimated that 30 to 62 percent of cases could be prevented by switching from reusable soft lens to DD lens use.

"Given that an estimated 300 million people across the globe wear contact lenses, it is important that people know how to minimize their risks for developing keratitis," a coauthor said in a statement. "Contact lens packaging should include information on lens safety and risk avoidance, even as simple as 'no water' stickers on each case, particularly given that many people buy their lenses online without speaking to a health professional."

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