Contact Lens Care & Compliance
New Solutions, Innovations
BY MICHAEL A. WARD, MMSC, FAAO
Abbott Medical Optics (AMO) will launch its new RevitaLens Ocutec Multipurpose Disinfecting Solution (MPDS) in the United States at the American Academy of Optometry meeting later this month, after its inital launch in Europe in early 2010. It is a next-generation, dual disinfection MPDS designed to provide superior antimicrobial efficacy along with enhanced lens wearing comfort. RevitaLens Ocutec is classified as a stand-alone multipurpose disinfecting product with a required soak time of four hours. AMO recommends a rub and rinse regimen with its products.
How It Works
RevitaLens Ocutec utilizes a dual disinfection system with the biguanide alexidine dihydrochloride at 0.00016% in combination with polyquaternium-1 (PQ-1) at 0.0003%. PQ-1 is the primary antimicrobial in Alcon's Opti-Free Express and Opti-Free Replenish products, as well as an ingredient in Bausch + Lomb's new Biotrue multipurpose solution.
Alexidine is a broad spectrum biocide commonly used in mouthwashes. It is an amphipathic bisbiguanide that acts as an antimicrobial, but can also neutralize bacterial membrane components as potential stimulators of inflammation. Alexidine has been shown to prevent macrophage activation in the presence of bacteria and to suppress inflammatory responses caused by activation of toll-like receptors (TLRs). Although alexidine is not currently found in ophthalmic products, it was previously used as a component in Renu with MoistureLoc (RML, B+L) MPS, which was removed from the market in 2006 due to RML association with outbreaks of fungal keratitis. It's since been proven that alexidine was not a culprit in the RML product deficiency, rather it was due to evaporative films formations. AMO claims that RevitaLens Ocutec possesses superior antimicrobial activity against Acanthamoeba trophozoites and cysts, as well as against all challenge bacteria and fungi, including Fusarium.
Figure 1. The new RevitaLens Ocutec MPDS.
RevitaLens Ocutec is buffered with sodium borate. Borates go beyond buffering capabilities and may exhibit microbiostatic and even microbicidal effects, therefore contributing to overall antimicrobial effectiveness.
RevitaLens Ocutec contains Tetronic 904, a block copolymer surfactant that provides lubrication through its mucoadhesive properties. Ethylenediaminetetraacetate (EDTA) is a chelant that binds free metal ions (Ca++, Mg++), thus decreasing deposit formation, and destabilizes bacterial cell walls, adding to the product's antimicrobial properties.
From 2004 to 2006, we witnessed the last significant introduction of new soft contact lens care products from the major manufacturers, followed by two significant product recalls. The industry has corrected the shortcomings of those earlier products, and better solutions are now emerging. Although the FDA's requirements for new solutions are still a work in progress, these are exciting times for new lens care products, which are emphasizing powerful antimicrobial efficacies along with ocular surface protections and associated lens wearing comfort. CLS
Mr. Ward is an instructor in ophthalmology at Emory University School of Medicine and Director, Emory Contact Lens Service. He is also a consultant for AMO. You can reach him at email@example.com.