[ad_1]
People who wear contact lenses are often warned to properly clean their reusable contacts. A new study released Friday provides a sober reminder of why these warnings exist. Since 2011, an epidemic of a rare infection that can cause blindness has been prevalent among lens wearers in England, often due to poor hygiene.
The infection is caused by unicellular amoebae belonging to Acanthamoeba kind, which gives its name to the disease: Acanthamoeba keratitis. Unlike the flu or the cold virus, however, these people do not really want to infect and infect people. They prefer to live in the soil or in fresh water, where they can feast on bacteria to their content (figurative). But when these amoebae enter our eyes, they can cause open wounds in the cornea that permanently damage our eyesight.
Acanthamoeba keratitis is rare, but its rarity is still debated. Some studies have estimated that only 1.2 cases per million adults in the United States each year. But we know that contact lens wearers are at higher risk. According to the Centers for Disease Control and Prevention, approximately 85% of the estimated cases in the United States occur in lens wearers.
In recent years, the authors of the current study have noticed what appeared to be a rise in cases in southeastern England. They decided to consult the patient files of the Moorfields Eye Hospital, a large hospital in the area where cases of Acanthamoeba keratitis. They examined cases over a period of 20 years, from 1986 to 2016.
From 2000 to 2003, they found less than ten cases a year. But as of 2010, the annual incidence of Acanthamoeba keratitis was three times greater than from 2004 to 2009.
In the hope of determining the exact cause of the outbreak, they then compared some of these patients to a control group of other contact lens wearers who had visited the hospital. Both groups completed surveys on how they handled and used their lenses.
The researchers found that the risk of infection was more than three times higher among respondents who often did not clean their lenses; who were not great hand washers; who swam or used spas while wearing lenses; or who used a special disinfectant called Oxipol to clean their lenses. But, according to the authors, none of these factors is probably the only reason for the increase in the number of cases.
The results were published in the British Journal of Ophthalmology,
"This infection is still quite rare, usually affecting 2.5 to 100,000 lens users a year in southeastern England, but largely preventable," said John Dart, a researcher at the University. College London and Ophthalmologist at Moorfields Eye Hospital. "This increase in the number of cases underscores the need for contact lens users to be aware of the risks."
Practical steps have already been taken to curb the epidemic. Manufacturers of a brand of reusable lenses often used by patients in the study have since stopped using Oxipol as a disinfectant. But there are some things that lens wearers will have to do to avoid an amoeba.
"People who wear reusable contact lenses should be sure to thoroughly wash and dry their hands before handling contact lenses and avoid wearing them while swimming, washing their face or taking bath, "explains Dart. "Daily disposable lenses, which eliminate the need for contact lens cases or solutions, may be safer and we are currently analyzing our data to determine the risk factors for them."
It could be worse, though. At least they are not eyeworms.
Source link
