people who use contact lenses Nearly four times more likely to develop reusable Acanthamoeba keratitisAccording to a study led by researchers at University College London and Moorfields Eye Hospital, a rarer sight-threatening eye infection compared to daily disposable lens wearers.
Case-control study, published in Ophthalmology, identifies several risk factors of this pathology, a type of microbial keratitis that causes inflammation of the cornea (the transparent protective outer layer of the eye) and requires intensive treatment and even corneal transplantation, leaving severe sequelae in vision Is. Among the habits that can increase the chances of suffering from it: reuse of lenses or during its use at night or in the shower,
“In recent years, we have seen aggravated keratitis by Acanthamoeba in the UK and Europe, and although infection is still rare, it is preventable and requires a public health response,” said lead author Professor John Dart, from the UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust.
“Contact lenses are generally very safe, but they are associated with a small risk of microbial keratitis, most commonly caused by bacteria, which is the only sight-threatening complication of contact lens wear. Worldwide With about 300 million people wearing contact lenses in the U.S., it is important for people to know how to reduce their risk of developing keratitis,” says Dart.
Vision loss from microbial keratitis is uncommon, but Acanthamoeba, although a rare cause, is one of the most serious, accounting for about half of contact lens wearers who develop vision loss after keratitis. 90% of cases are associated with avoidable risks, although infection remains rare, affecting less than 1 in 20,000 contact lens wearers a year in the UK.
Acanthamoeba keratitis causes pain in the front surface of the eye, the cornea and becomes inflamed due to infection with Acanthamoeba, a cyst forming microorganism, The most severely affected patients (a quarter of the total) end up with less than 25% vision or become blind after illness and face long-term treatment. Overall, one in four affected people require a corneal transplant to cure the disease or restore vision.
For the study, researchers recruited more than 200 Moorfields Eye Hospital patients who completed a survey that included 83 people with the condition, and compared them to 122 participants who attended eye care clinics with other conditions. participated, served as a group of controls.
People who wore reusable soft contact lenses (such as monthly ones) were 3.8 times more likely to develop Acanthamoeba keratitis than those who wore disposable lenses daily. Showering with contact lenses increased the odds by 3.3 times, there was a 3.9-fold increase in the odds when wearing contact lenses at night. In daily disposable contact lens wearers, reuse increased the risk of infection. Conversely, the risk is lower with a recent lens examination by a healthcare professional.
A recent study led by Professor Dart found that the prevalence of this type of keratitis is increasing in the UK. Reviewing Moorfields Eye Hospital incidence data from 1985 to 2016, he and his team found an increase from 2000-2003, when it increased from eight to 10 cases per year at the end of the period to between 36 and 65 cases per year. . ,
“Previous studies have linked Acanthamoeba keratitis to contact lens wear” hot tubs, pools or lakes, and here we’ve added showerheads to that list, emphasizing that exposure to water should be avoided while wearing lenses. Public swimming pools and coastal authorities can help reduce this risk by advising against swimming with contact lenses,” explains Nicole Carnt, associate professor at the UCL Institute of Ophthalmology and Moorfields Eye Hospital and first author of the study.
In Dart’s opinion, “contact lens boxes should include information about risk prevention, even something as simple as a contact lens sticker. ‘there is no water’ In any case, given that many people buy their lenses online without talking to a health professional«. In addition, the study’s lead authors remind that basic hygiene measures When wearing contact lenses can go a long way in preventing infection, “like” wash hands thoroughly and dry Before putting on contact lenses.