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.

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.

New research shows several strains of bacteria can form biofilms on contact lenses, making the microbes more resistant to lens disinfection with contact lens solutions. In the September 2009 issue of the medical journal Cornea, researchers reported the results of a recent study of bacterial biofilms grown on silicone hydrogel contacts.

The researchers designed a study to determine if three types of bacteria associated with contact lens-related eye infections (Pseudomonas aeruginosa, Serratia marcescens and Staphylococcus aureus) form biofilms on silicone hydrogel contacts, and what effect this might have on the ability of contact lens solutions to effectively disinfect contacts.

Biofilms are collections or aggregates of microorganisms that adhere to a surface (such as a contact lens or contact lens storage case) and to components of the biofilm itself.

The researchers found that all three types of bacteria studied form biofilms on silicone hydrogel contact lenses. When examined microscopically, the biofilms consisted of dense networks of cells arranged in multiple layers, forming a matrix with extracellular material.

The study also demonstrated that the biofilms formed by these bacteria decreased the disinfecting effectiveness of common multipurpose contact lens solutions.

This research confirms the importance of proper contact lens care and scheduled replacement of disposable contacts to decrease the build-up of bacterial biofilms on contact lenses that may increase the risk of contact lens-related eye infections.

You can learn more about contact lens biofilms here.

What is the best method for cleaning and disinfecting your contact lenses?

In a recent issue of Contact Lens Spectrum, two prominent researchers addressed this issue in a point-counterpoint debate.

Charlotte Joslin, OD, PhD, epidemiologist and assistant professor of ophthalmology and visual sciences at the University of Illinois at Chicago, prefers hydrogen peroxide-based contact lens solutions. She says that a recent study found that only a two-step hydrogen peroxide lens care system was effective against a microorganism that can cause a serious eye infection called acanthamoeba keratitis.

In addition to being proven effective against Acanthamoeba organisms, two-step hydrogen peroxide-based (HPB) contact lens care solutions also are the most effective against bacterial and fungal eye infections, according to Dr. Joslin. She also said that there have been two worldwide recalls of (non-hydrogen peroxide) multipurpose contact lens solutions due to outbreaks of amoeba and fungal eye infections associated with the use of these one-step solutions.

Dr. Joslin’s argument was countered by Craig A. Woods, PhD, research manager at the Centre for Contact Lens Research, School of Optometry, University of Waterloo (Ontario, Canada).

Dr Woods believes multipurpose contact lens care solutions offer the best combination of safety, cost and effectiveness.

He says that one-step (”no rub”) multipurpose solutions are less expensive and easier to use than HPB disinfecting solutions, and contact lens wearers are more likely to use them properly. He says that there have been “only rare reports” of complications associated with multipurpose solutions, and that they are proven safe and effective.

Dr. Woods also says that hydrogen peroxide-based lens care systems require contacts to be exposed to the hydrogen peroxide solution for a significant amount of time, and that single-step HPB systems may not allow sufficient time for complete disinfection.

He says that while the recent outbreaks of eye infections that caused global recalls of certain multipurpose care solutions were “horrendous for the individuals involved,” he believes these were isolated incidents and not representative of the overall performance of multipurpose disinfecting solutions.

The full point-counterpoint discussion of contact lens care solutions featuring Drs. Joslin and Woods appears in the June 2009 issue of Contact Lens Spectrum.