A new long-term study aims to determine whether orthokeratology with specially designed gas permeable (GP) contact lenses can safely and effectively control the progression of nearsightedness in children.

The clinical study, called the Stabilizing Myopia by Accelerating Reshaping Technique (SMART) study, will compare the progression of myopia among 267 children ages 8 to 14 that have been enrolled in the study. The research is taking place at 10 clinical research sites throughout the United States.

A total of 162 of children enrolled in the study have been successfully fit with the ortho-k contacts and will wear the GP lenses on an overnight basis throughout the five-year study period. The overnight ortho-k lenses enable the subjects to see clearly throughout the day without glasses or contact lenses.

A control group of 105 children in the study will wear silicone hydrogel contact lenses on a daily wear basis throughout the study, replacing the lenses monthly.

At yearly intervals, the children wearing the ortho-k lenses will return the gas permeable contacts to one of the study’s investigators and will be given soft contact lenses to wear temporarily. While wearing the soft lenses, the subjects’ eyes will be examined every three days until their myopia has stabilized.

The investigator will then compare this amount of myopia with how nearsighted the child was at the beginning of the study to determine the net effect of the ortho-k lenses on slowing the progression of nearsightedness. After this comparison is made, the participant will again wear the ortho-k lenses for another one-year period.

The researchers say the five-year SMART study will offer more information about the safety and effectiveness of overnight orthokeratology than previous ortho-k studies, which typically have evaluated subjects over a period of no more than two years and often for six months or less.

You can follow the progress of the research and get the latest updates by visiting the SMART Clinical Trial page on Facebook.

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.

This week, Unilens Vision Inc. (Largo, Fla.) launched C-VUE Advanced Toric Multifocal contact lenses. These specialty lenses correct both astigmatism and presbyopia.

According to the 1999-2004 National Health and Nutrition Examination Survey (NHANES), approximately 36 percent of Americans ages 20 and older have astigmatism. Presbyopia is an age-related vision problem that affects virtually everyone some time after age 40.

Eye doctors can customize the new C-VUE Advanced Toric Multifocal lenses for their patients by specifying astigmatic and multifocal powers, multifocal zone size, lens diameter, base curve and more. The monthly disposable contact lenses also feature advanced hydration properties for all-day comfort, according to the company.

Unilens Vision Inc. offers a free trial program and a 120-day performance guarantee. The lenses are available exclusively from independent eye care professionals. Read more at www.unilens.com.