Contact lenses alert after rise in eye infection which can blind
DOCTORS have warned contact lens wearers to take more care after a trebling in the cases of an eye infection which can cause blindness.
It is caused by a micro-organism in water burrowing into the cornea and forming a cyst.
The disease was found in people wearing reusable lenses which had become contaminated or who had been swimming while wearing their lenses. Poor contact lens hygiene was also blamed.
The number of cases of the infection called acanthamoeba keratitis, known as ‘AK’, has tripled since 2011, according to a study at Moorfields Eye Hospital in London.
Lead author Professor Jonathan Dart said: ‘This infection is largely preventable. This increase in cases highlights the need for users to be aware of the risks.’
The most severely affected AK patients, a quarter of the total, become blind or are left with less than 25 per cent of their vision and face prolonged treatment.
Around one in four who are affected need corneal transplants to treat the disease or restore vision. Although anyone can be infected, contact lens users face the highest risk due to an increased susceptibility to infection, for reasons not fully known, as a result of wearing them. Another factor is the contamination of lens cases.
Researchers examined data from Moorfields from 1985 to 2016. They found a rise in AK cases dating from 2000-2003, when there were eight to ten cases a year, to between 36-65 cases annually in the past few years.
As Moorfields treats more than a third of AK cases in the UK, the study findings are relevant to the UK more broadly. The study’s case-control research included 63 people with AK and 213 without.
It found the risk of developing the disease was more than three times greater among people who did not always wash and dry their hands before handling lenses and for those who wore them while swimming or in hot tubs.
Showering and face washing while wearing contact lenses were also likely to be risk factors.
Acanthamoeba occurs more in the UK than other countries, probably due to higher levels found in water supplies in homes.
The study said the outbreak is unlikely to be due to any one factor in isolation.
Professor Dart said: ‘ Daily disposable lenses may be safer and we are analysing our data to establish the risk factors for these.’
Irenie Ekkeshis, of Acanthamoeba Keratitis Patient Support Group UK said: ‘This research confirms what those of us affected by AK have suspected: that incidences of this life-changing infection are on the increase and more should be done. It is imperative that regulators and those in the optical sector take immediate and urgent action on prevention.’