Replacing your contact lens case frequently reduces the risk of contamination that can lead to contact lens-related eye infections, according to a new study.

In research designed to evaluate the relationship between the age and contamination of storage cases for contact lenses, investigators at the Institute for Eye Research and the School of Optometry and Vision Science at the University of New South Wales (Sydney, Australia) collected 64 lens cases from contact lens wearers who had no symptoms of eye problems.

Most of the participants in the study (95 percent) wore soft contacts. The researchers did not specify how many of these soft lens wearers wore color contacts. They also did not say if any of the participants wore theatrical contact lenses.

The contact lens solutions used by most participants were one-step multipurpose solutions (83 percent).

Bacterial and/or fungal contamination was found in 58 percent of the cases. There was no significant difference in the risk of contamination based on the brand of contact lens solution used.

Lens cases that were less than nine months old had a significantly lower risk of being contaminated than older cases.

The researchers concluded that the results of the study suggest that replacing contact lens cases frequently reduces the risk of contamination, and said the general consensus among optometrists is that contact lens cases should be replaced every 3 to 6 months.

SOURCE: Profile and frequency of microbial contamination of contact lens cases. Optometry and Vision Science. March 2010.

In today’s issue of Contact Lenses Today, optometrist and contact lens specialist Morris Lehrfeld, OD, shares the following tips he gives to his patients to help keep their eyes healthy when wearing contact lenses:

1. Use only solutions prescribed by your eye doctor. Older and generic contact lens solutions can cause compatibility issues, especially with modern silicone hydrogel contacts, says Dr. Lehrfeld.
2. Use fresh contact lens solution every day. Many contact lens wearers are guilty of “topping off” the contact lens solution left in their lens case from the previous day. This reduces the effectiveness of the disinfection process, potentially leading to serious contact lens-related eye infections.
3. Replace your contact lens case at least every three months. Even with proper lens care, bacteria and other infection-causing agents can accumulate in contact lens cases over time. Routine replacement of your lens case can reduce the risk of contamination and eye infections.

Dr. Lehrfeld is an eye care provider at Palatine Vision Center, a group optometric practice in Palatine, Illinois. Contact Lenses Today is a weekly e-mail newsletter for eye doctors sponsored by the professional journal, Contact Lens Spectrum.

In this month’s issue of Contact Lens Spectrum, editor and contact lens specialist Jason J. Nichols, OD, warns that current economic conditions may be affecting how people are wearing and caring for their contact lenses.

Dr. Nichols says hard economic times can alter people’s behavior regarding their health, including how frequently they replace their contacts and how they use contact lens solutions.

“I am hearing more and more reports of patients looking for the cheapest ‘bottle’ on the shelf, which just happens to be saline rather than an appropriate care solution,” he says. Many contact lens wearers may also be using their lenses for longer periods of time rather than discarding and replacing them according to the schedule their optometrist or ophthalmologist recommends, according to Dr. Nichols.

Internet blogs and social networking sites may be contributing to the problem: some sites feature discussion boards where contact lens wearers report how they routinely wear their disposable contacts longer than recommended.

Dr. Nichols warns that poor contact lens habits frequently lead to contact lens-related eye infections, including severe infections like Acanthamoeba keratitis. He urges eye doctors to continue educating and re-educating their patients about proper contact lens wear and care.

In a related story published in the journal, a survey released by the American Optometric Association indicates 52 percent of consumers are visiting their eye doctor less frequently due to economic reasons. The same survey says 59 percent are visiting their primary care physician less frequently.

Silicone hydrogel contact lenses, even more than conventional soft contacts, require a rubbing step when cleaning and disinfecting the lenses with “no-rub” contact lens solutions, says a prominent contact lens specialist.

Michael A. Ward, MMSc, FAAO, instructor in ophthalmology at Emory University School of Medicine (Atlanta, Ga.) and director of Emory Eye Center’s Contact Lens Service, says adding the manual cleaning step maximizes comfort, improves vision and reduces the risk of contact lens-related eye infections.

Researchers are finding that one-step (”no-rub”) contact lens solutions often do not completely remove environmental debris, skin oils and make-up from the surface of contact lenses. These lens deposits can cause eye discomfort and vision problems, and may also decrease the effectiveness of lens disinfectants and lead to serious problems, including bacterial and fungal eye infections and Acanthamoeba keratitis.

Silicone hydrogel lenses, which allow more oxygen to reach the cornea than regular soft contacts, are as likely as regular soft lenses to accumulate lens deposits if they are not properly cleaned and disinfected after each wearing period.

If patients at Emory Contact Lens Service are not compliant with a rub-and-rinse lens care regimen and lens deposits are noted, switching to a hydrogen peroxide-based lens care system often solves the problem, Ward told online newsletter Contact Lenses Today (Oct 22).

Another option for people who are prone to contact lens deposits or fail to care for their lenses properly is to switch to daily disposable contacts, which are designed to be discarded after a single use.