This article is more than 5 years old. Information may no longer be current.
Free-living amoeba may cause keratitis in cosmetic contact lenses
Click Here to Manage Email Alerts
The public should be aware of possible cosmetic contact lens contamination with potentially pathogenic free-living amoeba that can directly or indirectly cause keratitis, according to researchers in Eye & Contact Lens.
One hundred cosmetic contact lens (CCL) symptomatic wearers in Thailand were randomly selected and questioned regarding their lens use, and a pair of their CCL was obtained.
Most participants (85%) wore lenses for vision correction, while 15% had normal eyesight, but all participants were wearing lenses for reasons of cosmetic appearance or convenience.
Nearly half of the participants were experienced wearers.
Of the CCL types worn, 88% of wearers used normal size CCL (less than 14.5 mm), whereas 12% used monthly disposable lenses, 3% wore daily disposable lenses and 3% wore yearly disposable lenses.
A total of 86% of wearers reported eye irritation, and 53% reported they had experienced redness of the eyes.
For cleaning and soaking lenses, 86% used multipurpose solution, 13% used both multipurpose solution and normal saline, and one participant used only normal saline.
Regarding CCL knowledge, 35% of wearers correctly answered nine or 10 questions and were classified as having good knowledge, whereas 47% correctly answered seven or eight questions, 10% correctly answered five or six questions, and 8% correctly answered four questions or fewer, as having moderate, fair or inadequate knowledge, respectively.
As for hygiene, most participants had good (51%) and excellent (40%) behaviors.
Two pairs of CCLs were contaminated with free-living amoeba (FLA). Acanthamoeba-like trophozoites were observed on the PYG [peptone yeast glucose] medium from the first contaminated CCL. The risk of contamination involved the exclusive repeated use of the commercially prepared saline solution without preservatives for cleaning and soaking the CCL until it is empty.
The contaminant of the second pair of CCL was Vahlkampfia-like trophozoites, attributed to swimming while wearing lenses.
In addition to poor hygiene, contaminated contact lens solutions and contamination of contact lens storage cases are important causes of keratitis, according to researchers.
While this study shows low contamination rates of FLA, this is the first report describing the presence of potentially pathogenic FLA in used CCL from asymptomatic wearers, researchers wrote. – by Abigail Sutton
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts