The risk of a rare sight-threatening eye infection is nearly four times greater for people who use reusable contact lenses than for those who wear disposable lenses daily, according to a new study. new research.
Acanthamoeba keratitis (AK) is an infection of the cornea, and is a condition that leads to inflammation of the cornea – the clear protective layer of the eye.
The study, led by the UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust – identified several factors that increase the risk of AK, including reusing lenses or wearing them overnight or in the shower.
More than 200 hospital patients completed a survey, including 83 with AK and 122 visiting eye clinics with other conditions.
Researchers found people who wore reusable soft contact lenses – such as laurel glasses – were 3.8 times more likely to develop AK than those who wore disposable contact lenses. daily.
Showering with lenses increases AK’s odds by 3.3x, while wearing lenses overnight increases this rate by 3.9x.
Researchers estimate 30-62% of cases, in the UK and many other countries, could be prevented if people switched from disposable to disposable glasses.
They have recommended that people avoid wearing their lenses while swimming or in the shower, and that the packaging has a “water-free” label.
Although vision loss from infection is uncommon, Acanthamoeba, although a rare cause, is one of the most serious and causes about half of contact lens wearers. lens loss of vision after keratitis.
Around 90% of AK cases are associated with avoidable risks although the infection remains rare, affecting less than one in 20,000 contact lens wearers each year in the UK.
The most severely affected patients – a quarter of the total – have 25% less vision or go blind.
Overall, 25% of affected people required a corneal transplant to treat the disease or restore vision, the study found.
Lead author Professor John Dart said: “In recent years, we have seen an increase in Acanthamoeba keratitis in the UK and Europe, and while infection remains rare, it is possible. preventable and requires a public health response.
“Contact lenses are generally very safe, but there is a small risk of bacterial keratitis, most commonly caused by bacteria, and this is the only vision-threatening complication with their use.
“With an estimated 300 million people globally wearing contact lenses, it’s important for everyone to know how to reduce their risk of developing keratitis.”
The study, published in the Journal of Ophthalmology, was funded by Fight for Sight, the NIHR Moorfields Biomedical Research Center and the Moorfields Eye Charity.