A new outbreak of a rare but preventable eye infection that can cause blindness, has been identified in contact lens wearers in a new study led by UCL and Moorfields Eye Hospital researchers.
The research team found a threefold increase in Acanthamoeba keratitis since 2011 in South-East England.
Reusable contact lens wearers with the eye infection are more likely to have used an ineffective contact lens solution, have contaminated their lenses with water or reported poor contact lens hygiene, according to the findings published today in the British Journal of Ophthalmology. “This infection is still quite rare, usually affecting 2.5 in 100,000 contact lens users per year in South East England, but it’s largely preventable. This increase in cases highlights the need for contact lens users to be aware of the risks,” said the study’s lead author, Professor John Dart (UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust).
Acanthamoeba keratitis is an eye disease that causes the front surface of the eye, the cornea, to become painful and inflamed, due to infection by Acanthamoeba, a cyst-forming microorganism.
The most severely affected patients (a quarter of the total) have less than 25% of vision or become blind following the disease and face prolonged treatment. Overall 25% of people affected require corneal transplants to treat the disease or restore vision.
Anyone can be infected, but contact lens users face the highest risk, due to a combination of increased susceptibility to infection, for reasons not fully established, as a result of contact lens wear and contamination of lens cases.
The researchers collected incidence data from Moorfields Eye Hospital, from 1985 to 2016. They found an increase dating from 2000-2003, when there were eight to 10 cases per year, to between 36-65 annual cases in the past few years. As Moorfields treats more than one in three cases of the disease in the UK, the researchers expect their findings are relevant to the UK more broadly.
Alongside these findings, they conducted a case-control study of people who wear reusable contact lenses on a daily basis (although the disease is also associated with disposable lenses), comparing those who had a diagnosis of Acanthamoeba keratitis to those who had come in to Moorfields A&E for any other reason, from 2011 to 2014.
Read more at University College London