Are Contact Lenses Safe? Cases of Rare Eye Infection That Can Cause Blindness May Be Increasing

Cases of an uncommon eye infection that can cause blindness may be increasing because of something that's used every time contacts are inserted: water.

Scientists at Moorfields Eye Hospital in London noticed an increasing number of patients being diagnosed with a rare eye infection. Published in the British Journal of Ophthalmology on September 19, the study confirmed that infections from Acanthamoeba keratitis have grown—and the source is easy to avoid.

Acanthamoeba keratitis is caused by a microscopic amoeba that infects the cornea, which is the outer, transparent cover of the eye. According to the Centers of Disease Control and Prevention, when the Acanthamoeba amoeba enters the eye, it can cause a range of symptoms, such as eye redness, blurred vision, and eye pain, and without treatment, can lead to vision loss or blindness. Acanthamoeba amoebas are often found in water, such as wells or the pipes in plumbing.

"We think any water exposure is a risk for the disease," John Dart, a professor at University College London, consultant at Moorfields Eye Hospital and author on the study told Newsweek. "Unlike bacteria infections which are more common, this is 90 percent preventable."

However, once the infection is contracted, it can be hard to treat.

"We recently studied 196 patients and a quarter of them were required more than 10 months treatment, three years follow up, and thirty hospital visits," Dart explained. Only about 70 percent can be cured in 12 months without surgery and most of the patients are young people. "We don't have drugs that work quickly for every patient."

Dart's team noticed that the number of cases had grown in recent years. Between 2010 and 2011, there were about 10 to 18 cases at Moorfields, but by 2013, there were between 36 and 65. Dart said overall, they've seen around a 3-fold increase in cases. The latest outbreak was likely due to contaminated contact lens solution, he thinks. In the past, in the U.S., there have been outbreaks because of both homemade and store-bought solutions.

While the infection is more common in the U.K., people in the U.S. can still follow a new contact lens routine to avoid infection. Dart recommended placing a warning to avoid water on the contact lens packaging.

"Avoid water and follow the instruction on the solution. If you use solution, change your contact lens case every month," Dart said. He also recommended washing and completely drying hands before touching contacts, as well as changing them after showering, washing one's face, or swimming.