Since Acanthamoeba can survive in the space between the lens and the eye, people who wear contact lenses are at higher risk of infection.
The paper titled ‘Acanthamoeba keratitis: confirmation of the UK outbreak and a prospective case-control study identifying contributing risk factors’ was published in the British Journal of Ophthalmology on September 19.
What is responsible for the infection?
The infection, known as Acanthamoeba keratitis is caused by a single-celled microorganism called Acanthamoeba. It is found in environments all over the world, including water bodies and soil.
While anyone could be infected, people who wear contact lenses are at higher risk since the amoebae can survive in the space between the lens and the eye. According to the Centers for Disease Control and Prevention, contact lens wearers make up 85 per cent of cases in the United States.
How prevalent is the infection?
Though prevalence has risen, overall incidence is still rare. However, the findings from the new study specifically looked at South-East England.
Using data from Moorfields Eye Hospital, the researchers studied cases recorded over three decades, from 1985 to 2016. An increase was observed between the early 2000s (eight to 10 annual cases) and in recent years (36 to 65 annual cases).
“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 lead author John Dart, a professor at the UCL Institute of Ophthalmology.
How dangerous could it be?
In the worst case scenario, the disease might result in permanent blindness or poor vision. This occurs as a result of trauma after the amoebae invade the cornea. According to a 2015 study, symptoms usually involve massive pain, photophobia, and tearing.
“The sooner the disease is diagnosed, the better the outcome,” the authors wrote. “If diagnosis is delayed, the amoebae have already penetrated deeply into the corneal stroma and successful therapy becomes exceedingly difficult.”
What precautions can people take?
The rise in cases is probably due to a number of factors rather than a single reason, the researchers suggest. But above all, practicing good hygiene with your lenses can significantly eliminate the risk of infection.
This means never reusing or topping off old solution while cleaning and storing them. Storage cases should also be replaced at least once every three months.
“People who wear reusable contact lenses need to make sure they thoroughly wash and dry their hands before handling contact lenses, and avoid wearing them while swimming, face washing or bathing,” Dart added.
Source: Medical Daily