The CDC warn that if individuals who wear contact lenses do not take proper care of them, they may be at increased risk of keratitis.
Contact lenses - worn by around 38 million Americans - are a popular alternative to wearing glasses. But improper care of contact lenses can cause eye infections like keratitis, which can lead to blindness.
Dr. Jennifer R. Cope, a medical epidemiologist of the National Center for Emerging, Zoonotic and Infectious Diseases at the Centers for Disease Control and Prevention (CDC), and co-author of a new CDC Morbidity and Mortality Weekly Report (MMWR) on keratitis in the US, says:
"Contact lenses offer wearers good sight without the hassle of glasses, but they can also make wearers more prone to infection if they're not careful. Users should follow good hygiene and care steps every time they wear, clean and store their contacts to help keep their eyes healthy."
The CDC estimate that every year, nearly a million doctor visits in the US are for keratitis, incurring a direct health care cost of $175 million.
Most cases of keratitis - if caught early - are easily treated. If untreated, the condition can lead to inflammation, pain and even blindness.
Anyone who develops pain or inflammation in the eyes should see their doctor immediately - especially if they wear contact lenses - warn the CDC. Their new MMWR report states that contact lens wear is one of the primary culprits in cases of keratitis.
The authors note that:
"Among the estimated 38 million contact lens wearers in the US, poor storage case hygiene, infrequent storage case replacement and overnight lens wear are established preventable risk factors for microbial keratitis, contact lens-related inflammation and other eye complications."
Good hygiene habits for contact lens wearers
The CDC recommend the following steps to ensure good hygiene and habits in caring for and storing contact lenses in order to minimize the risk of keratitis:
- Wash hands with soap and water and dry them well before touching contact lenses
- Rub and rinse contact lenses in disinfecting solution every time you remove them
- Use only the contact lens solution recommended by an eye care provider
- Never top up the solution in the contact lens case; always use a fresh batch each time and never mix fresh solution with old or used solution
- Never use water or saliva to clean contact lenses and never store them in water
- Do not sleep in contact lenses unless prescribed to do so by an eye care provider
- Keep water away from contact lenses and take them out before showering, swimming or using a hot tub
- Take care of the contact lens case: rub and rinse it with contact lens solution, dry it with a clean tissue and store it upside down with the caps off after each use
- Replace the contact lens case with a new one every 3 months
- Visit an eye care provider at least every year, or more often if your health care provider recommends it
- Ask your eye care provider about how to care for your contact lenses and supplies
- If you experience pain, discomfort, redness in the eye or blurred vision, take your lenses out straight away and call an eye care provider
- Carry a pair of glasses with you in case you need to take out your lenses.
In April 2014, Medical News Today reported new research that shows bacteria survive longer in contact lens cleaning solution than previously thought. The researchers found that one type of bacteria - associated with a more severe case of keratitis that takes longer to heal - was able to survive for over 4 hours, much longer than the 10 minutes it takes to kill the majority of bacteria found in contact lenses.