Contact lenses can carry a serious and blinding infection

FRIDAY, Sept. 21, 2018 (HealthDay News) – British researchers warn that contact lens wearers must be on the lookout for a rare but potentially blinding ocular infection.

In southeastern England, cases of infection, called keratitis in Acanthamoeba, have tripled since 2011, according to a new study.

The disease is usually related to misuse of contact lenses.

The infection combines a tiny unicellular amoeba with bacterial keratitis. Once the eye is infected, the cornea becomes painful and inflamed because of this microorganism forming a cyst.

According to the research team, for one in four infected people, the disease results in a loss of most of their vision or blindness and faces prolonged treatment.

Although rare, outbreaks have also occurred in the United States, said an ophthalmologist.

"There have been some outbreaks in the United States, including inappropriate disinfection of contact lenses," said Dr. Jules Winokur, who practices at Lenox Hill Hospital in New York. He was not involved in the new study.

"In clinical practice, we regularly observe cases of acanthamoeba," he said. "Most often, these cases are present in patients wearing contact lenses that have been exposed to contaminated water, from pools, water parks or even showers at home."

"The treatment of acanthamoeba can be prolonged and difficult," explained Winokur. "Toxic drugs and even corneal transplantation can be necessary treatments."

The British study was conducted by Dr. John Dart, of the Institute of Ophthalmology of University College London. His team collected patient data from 1985 to 2016 at Moorfields Eye Hospital.

They found an increase in cases of the disease eight to ten times a year in 2000-2003, and 36 to 65 cases a year more recently.

Overall, 25% of those affected needed a corneal transplant to treat the disease or restore vision, the researchers said.

The Dart team also conducted a second study, this time in people who wore reusable contact lenses daily. The study compared the 63 cases of Acanthamoeba keratitis diagnosed with 213 people who went to the ophthalmic hospital for any other reason.

The Dart group found that the risk of developing the disease was more than three times higher in people with poor contact lens hygiene. This means that people who do not wash or dry their hands before handling their lenses or those who use a disinfectant product containing Oxipol is now abandoned.

In addition, according to the study, people who wore their contacts in pools or spas were also at risk, as were people who showered or washed their faces while wearing their lenses.

"People who wear reusable contact lenses should be sure to thoroughly wash and dry their hands before handling contact lenses and avoid wearing them while swimming, washing their face or taking bath".

"Daily disposable lenses, which eliminate the need for contact lens cases or solutions, may be safer and we are currently analyzing our data to determine risk factors," he said in a statement. university press.

Dart pointed out that "this infection is still quite rare, usually affecting less than 3,000 lens users a year in southeastern England, but it is largely preventable."

"This increase in the number of cases highlights the need for contact lens users to be aware of the risks," he added.

Dr. Matthew Gorski is an ophthalmologist at Northwell Health in Great Neck, New York. He acknowledged that good contact lens hygiene could prevent most cases of Acanthamoeba.

According to Gorski, this includes:

• Wash hands with soap and water before handling contacts.
• Disinfect, clean and properly store your contacts, including never using tap water to clean contacts.
• Remove contacts from your eyes before exposure to water, such as swimming, showering or bathing.
• Immediately remove contacts and consult your eye doctor if you have eye pain, sensitivity to light, red eyes, or change of vision.

The study was published on 21 September in the British Journal of Ophthalmology.

More information

For more information on keratitis in Acanthamoeba, visit the American Optometric Association.