Reusable contact lenses more than triple risk

People who wear reusable contact lenses are four times more likely than those who wear everyday disposables to develop a rare, sight-threatening eye infection, according to a study by UCL and Moorfields researchers.

Case study, published in ophthalmologyidentifies multiple factors that increase risk chokempa Keratitis (AK), including reusing or wearing lenses overnight or while showering.

AK is a type of bacterial keratitis (corneal infection) – a condition that leads to inflammation of the cornea (the eye’s protective outer layer).

Lead author, Professor John Dart (UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust) said: “In recent years, we have seen an increase in chokempa Keratitis in the UK and Europe, while infection remains rare, is preventable and warrants a public health response.

Contact lenses are generally very safe but are associated with a small risk of bacterial keratitis, which is mostly caused by bacteria, and is the only sight-threatening complication when used. Given that an estimated 300 million people worldwide wear contact lenses, it is important for people to know how to reduce their risk of developing keratitis. “

The use of contact lenses is now the main cause of bacterial keratitis in patients with healthy eyes in the Nordic countries. Vision loss caused by bacterial keratitis is uncommon but chokempaAlthough it is a rare cause, it is one of the most serious and is responsible for about half of contact lens users who develop vision loss after keratitis. 90% of AK cases are associated with avoidable risks, although infection is still rare, affecting less than 1 in 20,000 annual contact lens wearers in the UK.

AK causes the front surface of the eye, the cornea, to become painful and inflamed due to infection chokempaIt is a cyst-forming microorganism. The most affected patients (a quarter of the total) end up with less than 25% of their vision or go blind after illness and face prolonged treatment. Overall, 25% of those affected need a cornea transplant to treat the disease or restore vision.

For the study, researchers recruited more than 200 patients at Moorfields Eye Hospital who completed a survey, including 83 people with rheumatoid arthritis, and compared them to 122 participants who came to eye care clinics with other conditions, and who served as a control group.

People who wore reusable soft contact lenses (such as monthly lenses) had a 3.8 times more likely to develop AK, compared to people who wore daily disposable lenses. Showering with lenses in increased odds AK increased 3.3 times, while wearing lenses overnight increased odds by 3.9 times. Among daily disposable lens wearers, reusing their lenses increased the risk of infection. After a recent contact lens check with a health professional, reduce your risk.

With further analysis, the researchers estimated that 30-62% of cases in the UK, and possibly many other countries, could be prevented if people switched from reusable lenses to daily disposable lenses.

A recent study led by Professor Dart found that AK is increasing in prevalence in the UK. By reviewing incidence data from Moorfields Eye Hospital from 1985 to 2016, he and his team found an increase starting in 2000-2003, when there were 8 to 10 cases per year, to between 36 and 65 cases per year at the end of the study period.

“Previous studies have linked AK to wearing contact lenses in hot tubs, swimming pools, or lakes,” said first author, Associate Professor Nicole Karnett (University of New South Wales, Sydney, UCLA Institute of Ophthalmology and Moorfields Eye Hospital). We added showers to that list, emphasizing that exposure to any water should be avoided when wearing lenses. Public swimming pools and coastal authorities can help reduce this risk by advising against swimming in contact lenses.”

Professor Dart added: “Contact lens packaging should include information on lens safety and risk avoidance, even if it’s as simple as ‘no water’ labels in every case, especially given that many people buy their lenses online without talking to a health professional.”

“Basic contact lens hygiene measures can go a long way in avoiding infection, such as washing and drying hands thoroughly before putting in lenses.”

The study was funded by Fight for Sight, NIHR Moorfields Biomedical Research Center, and Moorfields Eye Charity.

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