People who wear reusable contact lenses are nearly four times more likely to develop a rare eye infection that could rob them of their vision, a study finds.
The British scientists behind the study also warned that wearing contact lenses in the shower, pool and while sleeping also increases the risk.
In the study, they looked at more than 200 daily or reusable contact lens users who came to clinics with an eye infection or other illness.
They found that Acanthamoeba keratitis (AK) — which inflames the surface of the eye and can lead to blindness — was much more common in those who put the same lenses in and out of their eyes.
The infection is triggered when the microorganisms get on contact lenses through a contaminated solution or dirty hands and then enter the eye through small tears.
Patients suffer from eye pain, redness, blurred vision, a cloudy vision in the eye and, in severe cases, may eventually lose their vision. Treatment involves antiseptics to be applied directly to the surface of the eye, possibly for six months to a year.
Pictured above is the cloudy looking eye which can be caused by an infection with Acanthamoeba keratitis (AK). About 85 percent of cases involve contact lens users (stock image)
Acanthamoeba Keratitis: The Eye Infection That Can Make You Blind
What is Acanthamoeba Keratitis (AK)?
This is an infection of the cornea, or surface of the eye, caused by a microorganism.
How do I catch the disease?
It is most common in contact lens wearers, but can infect anyone.
The disease is triggered when the microorganism gets into your eye, either by putting contact lenses in your eye with dirty hands, or standing in the shower or swimming pool wearing the lenses.
It then enters the eye through small cracks in the surface and causes the infection.
What are the symptoms?
Symptoms include blurred vision, a cloudy or dirty-looking cornea, eye pain, eye redness, and watery eyes.
It can take several days to weeks for these to appear after infection.
Does it jeopardize my vision?
If left untreated, the infection can lead to permanent vision loss and total blindness, the CDC says.
Other complications include inflammation of the eye that is painful and partial vision loss.
What is the treatment?
Patients are normally offered an antiseptic to clear the infection from the eye, which is applied directly to the surface.
This may be necessary for six months to a year.
Patients may also be prescribed antibiotics, and surgery may be required in some cases.
Professor John Dart, an ophthalmologist at Moorfields Eye Hospital in London, UK, who led the study, said: ‘In recent years we have seen an increase in Acanthamoeba keratitis (AK).
‘[But] although the infection is still rare, it is preventable and warrants a public health response.”
He added: ‘Previous studies have linked AK to wearing contact lenses in hot tubs, swimming pools or lakes, and here we have added showers to that list, underscoring the need to avoid exposure to water when wearing lenses. .
Contact lens packaging should include information about lens safety and risk avoidance, even as simple as ‘no water’ labels on every box, especially given that many people buy their lenses online without having to wear a contact lens. to talk to a health professional.’
In the study – pulled in the magazine Ophthalmology — Scientists searched hospital records for an emergency room in South East England for patients with daily or reusable contact lenses.
They found 83 cases of AK seen on the unit between January 2011 and August 2014.
They then checked data for the following year on contact lens users who came in for another illness, unrelated to the infection, and found 122 cases.
Each also completed a questionnaire about their contact lens type and daily activities.
The results showed that of the 83 AK cases, only 20 (24 percent) used daily contact lenses.
But the other 63 (76 percent) were people who used soft or hard reusable lenses.
Statistics showed that the risk of developing AK was 284 percent higher in those who used reusable lenses compared to daily disposables.
The scientists also examined whether certain activities made the infection more likely.
Of the 20 AK cases who answered the question whether they wore contact lenses in the shower, 12 (60 percent) admitted this.
In comparison, in the other group, that was 25 out of 66 (37 percent)
In the paper, scientists said reusable contact lens users were at greater risk because they were more likely to contaminate their lenses.
On how to reduce the risk, they said lenses should not be worn at night and contamination of the solution in which they are kept should be avoided.
Fewer than 100 Americans suffer from an AK infection each year.
But scientists warn the numbers are rising, with more than 85 percent of cases being detected solely in contact lens users.
Symptoms of the infection take several days to weeks to appear, but include blurred vision, eye pain, and eye redness.
The eye may also appear cloudy to others, or even feel like there is something in it.
Patients are normally offered antiseptics to be applied to the surface of the eye to treat it.
But they may also be prescribed antibiotics or even offered surgery to help treat the infection.
In the United States alone, an estimated 45 million people wear contact lenses.