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.

Rinsing silicone hydrogel contact lenses with an approved contact lens solution after removing them from the eye removes more than half the protein that accumulates on the lenses, according to a new study.

Researchers at The Ohio State University College of Optometry found that rinsing silicone hydrogel contacts thoroughly as part of a “no rub” lens care system removes protein deposits from the lenses significantly better than foregoing the rinse step.

Subjects participating in the study were fit with silicone hydrogel lenses manufactured by CIBA Vision and then wore the lenses on a daily wear basis for five days. They were instructed to use Aquify Multi-Purpose Disinfecting Solution (CIBA Vision) after each day of wear, following the manufacturer’s “no rub” care instructions.

The study participants then returned to the clinic and their lenses were removed by a gloved examiner. One lens was rinsed with the contact lens care solution and the other was not. Protein was then chemically removed from all lenses and quantified.

More than 50 percent more protein was chemically extracted from the lenses that did not undergo the rinse step after removal from the eye.

The results of the study suggest silicone hydrogel lenses have significantly less protein build-up if they are thoroughly rinsed with a multi-purpose contact lens care solution when removed from the eye. Including this rinse step as part of a “no rub” care system therefore may decrease the risk of contact lens discomfort and contact lens-related eye infections.

A full report of the study appears in the August 2009 issue of Optometry and Vision Science.

New SofLens daily disposable contact lenses by Bausch & Lomb offer the benefits of daily disposable contacts and an advanced optical design, according to the company. The new lenses feature Bausch & Lomb’s proprietary High Definition Optics, which is designed to reduce blur, halos and glare for optimal vision.

SofLens daily disposable contact lenses also feature a thin lens design and slow-release moisture formula for all-day comfort, which is key for sensitive eyes, the company says. As with all daily disposable lenses, contact lens care is unnecessary and there is less risk of lens deposit build-up, which can lead to eye infections.

For a free trial of SofLens daily disposable lenses and a High Definition Optics lens demo, visit www.soflens.com.